Removal of Cefotaxime Antibiotics from Hospital Wastewater using TiO2 and SiO2 Nanoparticles-Modified Polyethersulfone Membrane: Experimental and Computational Study

Removal of Cefotaxime Antibiotics from Hospital Wastewater using TiO2 and SiO2 Nanoparticles-Modified Polyethersulfone Membrane: Experimental and Computational Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Removal of Cefotaxime Antibiotics from Hospital Wastewater using TiO 2 and SiO 2 Nanoparticles-Modified Polyethersulfone Membrane: Experimental and Computational Study Zeinab Nikfarjam, Mohammad Momen Heravi, Mohammad Reza Bozorgmehr This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1494699/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Antibiotics may be regarded as novel and harmful contaminants in the ecosystem because of their increased usage worldwide and presence in wastewater, endangering people's health and the environment even in small amounts. Among the adverse effects of the compounds are drug resistance and alteration in biological cycles. The present study aims to remove one of the cephalosporin antibiotics (cefotaxime) from hospital wastewater using synthetic modified membranes containing nanoparticles based on the in vitro and molecular dynamics (MD) simulation study. To do so, first, Polyethersulfone (PES) polymeric membrane, silicon dioxide (SiO 2 ), and titanium dioxide (TiO 2 ) nanoparticles were synthetic in the practical phase. Then, the impact of different factors, including pH, concentration, and contact time, was examined on the efficiency of wastewater treatment. Thermodynamic studies were also conducted to identify and analyze the adsorption isotherms of the PES polymeric membrane. The results indicate that the PES polymeric membrane achieved the maximum surface adsorption at 37 ° C, 180 min contact time, and pH = 5. The simulations were performed using Materials Studio and LAMMPS molecular dynamics simulator. The efficiency of simulations was assessed when the boundary conditions and force field were determined. At various temperatures, the best operating temperature, adsorption isotherms, and membrane morphology have all been studied. The adsorption isotherms were determined on the membrane surface in a low-pressure range from 1 kPa to 10000 kPa and at three different temperatures 21°C, 28°C, and 37°C. According to the results, the adsorption rate of cefotaxime on the membrane at 21°C and 28°C is approximately 2.6 times the adsorption rate at 37°C and a pressure of 1 kPa. The distribution of molecules at the given temperatures, the position of the occupied membrane, and the membrane cavities for trapping cefotaxime molecules were all observed in the analysis of the density of cefotaxime adsorbed on the membrane surface. Finally, a good agreement was achieved between the simulation and experimental results for wastewater treatment. Antibiotic removal Membrane Cefotaxime Molecular dynamic simulations Figures Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Introduction Because of the potential negative environmental consequences of emerging contaminants, they have caught the attention of academics and the international community. Accordingly, several attempts have been undertaken for reflecting the significance of contaminant emissions into various environments and adopting all the actions or steps necessary. However, improving present water and wastewater treatment technologies and integrating them into a complete and cyclical water management system is a long-term solution to this problem [ 1 ]. Antibiotics are the most alarming of all emerging contaminants, given their contribution to the development of resistant bacteria, even at low concentrations [ 2 ]. It seems that antibiotics do not kill bacteria at low concentrations, but the bacteria respond to mutations by developing genes to defend themselves from antibiotics. It should be mentioned that antibiotics are capable of replicating these genes in different bacterial strains [ 3 , 4 ]. These contaminants need to be regarded as a challenge because the long-term consequences of these medications have yet to be explored since the environment is likely to encounter numerous resistant bacteria with no unique, efficient behaviors in the next few years. According to the World Bank, by 2050, the resistant bacteria will have killed 10 million individuals per year and forced 28 million individuals to fall into extreme poverty [ 5 , 6 ]. Further antibiotics usage leaves considerable residues entering the environment, infiltrating the ecosystem either directly or indirectly. In a variety of matrices, human and veterinary specific antibiotic residues have been found. According to the literature on the significant impact of antibiotic usage, antibiotic exposure has been demonstrated to affect the survival and growth of aquatic organisms significantly. Antibiotics are mostly acquired in natural waters (i.e., rainwater, seawater, and river water, and groundwater) from the wastewaters of municipal wastewater treatment facilities and pharmaceutical manufacturing facilities. The antibiotics discharged into the natural environment are expected to be propriety for municipal wastewater treatment facilities. Hence, pharmaceutical chemicals, particularly antibiotics, are identified as developing environmental pollutants classed as substances resistant to bioaccumulation, reflecting the antibiotics as toxic and hazardous chemicals [ 7 , 8 ]. Membrane processes are one of the most practical techniques utilized to separate medications, such as antibiotics since they are more efficient and less expensive. Emerging membrane technologies hold great potential for removing pollutants, such as antibiotics. The most significant maintenance characteristics of nanofiltration as a membrane separation technology for multivalent ions and organic substances at relatively low operating pressures make it appealing. The membrane separation technology is frequently utilized in drinking water quality monitoring, wastewater treatment, and industrial applications [ 9 ]. In a membrane process, there are usually two phases (permeability and selectivity) physically separated by a third phase (membrane). However, all membrane materials possess one common feature, i.e., they allow to flow of various materials through them selectively. That is to say, a membrane is a tool allowing materials to be separated concerning their molecular sizes [ 10 ]. Generally, membranes can be classified into two classes biological and synthetic. In addition, the types of constituent materials and manufacturing technology utilized to produce the membrane might result in various structures [ 11 ]. The polymer types are chosen for producing polymeric membranes concerning different factors, including thermal, chemical, and mechanical characteristics of polymers and parameters affecting the permeability of polymers, the challenge that is prominent significantly in producing porous membranes. For example, polysulfone (PSU) and polyethersulfone (PES) polymeric membranes are frequently utilized as raw materials to produce ultrafiltration and microfiltration membranes due to their high mechanical, thermal, and chemical endurance and their homogeneous characteristics. In general, availability, ease of processing, and optimized selectivity features of this polymer type makes it the dominant polymer in the production of membranes [ 12 , 13 ]. Polymeric membranes have a hydrophobic nature decreasing the water permeability and sensitivity to fouling and sedimentation, particularly the organic matter deposition. Thus, the structure of membranes is modified for enhancing their hydrophilicity, resulting in increased water flux, reversibility, and fouling resistance. Hence, different techniques are utilized for improving the membranes and increasing their hydrophilicity, characterized as a surface coating. Surface grafting and different surface modification techniques can change the surface chemistry enhance the membrane surface hydrophilicity and membrane bending. The employment of hydrophilic polymers combined with hydrophobic polymers, such as PES polymeric membrane, may result in the modified characteristics and morphology of the membranes. The employment of amphiphilic copolymers may result in the enhanced surface hydrophilicity and even bulk membranes. Also, mineral nanoparticles may enhance membrane efficiency because of some factors, such as microscopic particles, extended surface area, and intense activities [ 14 – 16 ]. One field of study in extensive membrane separation technology is nanomaterials that improve low fouling or antifouling membranes [ 17 ]. Accordingly, in this study, two different nanoparticles were utilized at the same time. In the present work, the MD simulations were also utilized. In summary, a molecular simulation is an important tool used to study polymer science, which can be utilized for polymer systems with a known configuration, and its characteristics can be determined at the molecular/micro scales. The MD simulations allow academics to evaluate the impact of systemic changes on the macroscopic characteristics of a system. Given the inability of polymer systems to show materials' behaviors at the atomic scale, the laboratory study of polymer systems is not essential for gaining a thorough knowledge of many phenomena, highlighting the significant contribution of molecular simulations in predicting and designing polymer systems to justify the effective laboratory techniques. Among the simulation techniques, the MD simulation technique is significantly effective in studying the polymer systems [ 18 ]. Each MD simulation consists of three stages: 1) Determining a series of initial conditions (initial position and speed of all particles), 2) selecting a proper potential function for describing the interactions between particles, and 3) the study of system changes over time by numerically integrating a series of classical Newtonian equations of motion for all system particles concerning the periodic boundary conditions, and managing temperature and pressure for the physical replication of the thermodynamic ensemble [ 19 ]. A variety of polymer solutions are utilized in different industrial applications, such as adhesives, dyes, coatings, polymerization, fiber membrane manufacturing, and so on. The molecular simulation techniques can give detailed data about the behaviors of chains in polymer solutions, predict the biomolecules' structures and chemical interactions, as well as the polymeric material behaviors, and recognize a variety of underlying molecular characteristics of membranes and processes [ 20 ] Materials And Methods Experiment: Different materials were used in the present study, including PES polymeric membrane as the primary polymer, polyvinylpyrrolidone (PVP) as an auxiliary polymer for porosity regulation, dimethylacetamide (DMA) as an organic solvent, SiO 2 and TiO 2 nanoparticles, and distilled water as anti-solvent (Table 1 presents the chemical structures of used materials). In addition, a UP400s-ultrasonic device (Sound Technology Development Ltd, Iran) was utilized in the coagulation technique for solution uniformization during the membrane synthesis. Furthermore, Shing Sing magnetic stirrer (Germany) with a variable round of 100–800 rpm was utilized for bubble removal from the solvent, besides a film applicator for filtrating the prepared solution. Membrane preparation method The weight ratios of 25% PES, 5% PVP, 1% SiO 2 , and 2% TiO 2 were considered for membrane production. First, two separate containers were used to prepare the solutions, one containing additive and auxiliary polymer, and 20% of the required solvent was placed on a magnetic stirrer. The other containing nanoparticles and the remaining solvent were sonicated at the minimum temperature in the ultrasonic device. Stirring was continued for a long time following the preparation of a homogeneous solution and the addition of the contents of the first container, and then the bubbles were allowed to escape completely after the necessary period of time. Finally, a film applicator of a specific thickness was used to transfer the solution to the glass. Next, a coagulation bath was used for preparing the membrane that was then transferred to another distilled water container for solvent removal. In this phase, any quantity of PVP that can be dissolved in water is removed from the film by dissolving it in water. The scanning electron microscope (SEM) and atomic force microscope (AFM) (Figs. 1 and 2 ) imaging techniques were used to capture an image from the adsorbent surface structure for morphological analysis of the physical membrane surface. The number of adsorption-needed sites grows as the heterogeneous adsorbent surface is confirmed. The adsorption is also enhanced by the pores at the adsorbent surface. The synthetic membrane was characterized using the Fourier-transform infrared (FTIR) spectroscopy technique (Fig. 3 ). The membrane hydrophilicity was determined by conducting a contact angle test (Table 2 ). The membrane surface-water contact angle decreases by adding nanoparticles to the polymer solution, indicating that hydrophilicity of the membrane containing nanoparticles increases in comparison with the plain polymeric membrane. Table 2 The result of the contact angel test on the synthetic membrane. membrane Contact angel PES 68 PES TiO 2 – SiO 2 57.4 Impact of various parameters on the cefotaxime adsorption pH effect Tests were conducted at the pH values of 5, 7, and typical ones for examining the impact of pH on the adsorption. The pH value was regulated using sodium hydroxide and 0.1 M hydrochloric acid. The first was to complete adsorption in three wastewater samples containing cefotaxime antibiotics. After that, samples were taken at various pH values, and the quantity of drugs left in the wastewater was recorded. Impact of contact time and temperature on adsorption The tests were repeated at three 60, 120, and 180 seconds contact times, three 21°C, 28°C, and 37°C temperatures, and the constant pH value of 5 to examine the impact of contact time and temperature on the adsorption rate by keeping the adsorbent constant from the prepared membrane containing nanoparticles. The solution containing the left drug was then collected, and a spectrophotometer was then used to read and record its quantity. Impact of initial drug concentration in wastewater Tests were conducted at 10, 25, and 50 ppm by keeping constant other parameters to examine the impact of the initial concentration of cefotaxime on the adsorption. The quantity of drugs left in the solution was then measured. Determining the percent removal and adsorption capacity The percent antibiotic elimination (R) and the adsorption capacity (q e ) can be calculated as follows: $$\text{R}=\frac{(\text{C}\text{o}-\text{C}\text{e})}{\text{C}\text{o}}\times 100$$ 1 $$\text{q}\text{e}=\frac{(\text{C}\text{o}-\text{C}\text{e})}{\text{w}}\times \text{V}$$ 2 where C o , C e , V, w, R, qe denote the initial and final concentrations (mg/L) of antibiotic molecules in the solution, solution volume (L), solution mass (gr), removal efficiency (%), and adsorption capacity (mg/g), respectively. Finally, adsorption isotherms, corresponding associations, and the governing equations were evaluated. Then, for laboratory result confirmation, the Monte Carlo calculations were performed. Data analysis The pH effect on the cefotaxime adsorption using optimized synthetic membrane containing nanoparticles at the contact time of 120 min, the temperature of 28°C, and the membrane adsorption value of 2.5 mg is shown in Fig. 4 . As shown in the figure, because the concentration of hydrogen ions is low at the pH value of 7, and hydrogen ions are absorbed rather than medicinal ions, the minimum adsorption rate is at this pH value. Adsorption efficiency reduces as the pH value increases, leading to achieving the minimum percent adsorption at the pH value of 7. The type and ionic state of the adsorbent causative agents significantly affect the pH value of antibiotic adsorption. Consequently, it can be concluded that the pH value affects the adsorption equilibrium; thus, the pH value of 5 was chosen as the best pH, with the maximum cefotaxime adsorption by a membrane containing nanoparticles. The quantity of hydrogen ions and the antibiotic ions-adsorbent bond reduces by increasing the pH value. This most is likely due to an increase in inadequate retention time for the synthesis of active hydroxyl radicals and adequate time for the hydroxyl radical reaction to the cefotaxime molecules. The impact of contact time on the cefotaxime adsorption using optimized synthetic membrane containing nanoparticles at the pH value of 5, the temperature of 28°C, and the membrane adsorption value of 2.5 mg is shown in Fig. 5 . As shown in the figure, the fast adsorption in the contact time of 120 min is due to the abundant surface sites for cefotaxime adsorption on synthetic membranes containing nanoparticles. When the external sites are saturated after 120 min, further time is required for the adsorption to occur at the internal active sites. Since practically, all internal and external sites are saturated after 180 min, and the adsorption process achieves a state of equilibrium, so the best time is 180 min for the maximum drug adsorption (100% adsorption). The impact of temperature on the cefotaxime adsorption using optimized synthetic membrane containing nanoparticles at the pH value of 5, contact time of 180 min, and membrane adsorption value of 2.5 mg is shown in Fig. 6 . As shown in the figure, the efficiency of cefotaxime adsorption increases at the temperature of 28°C. The cefotaxime adsorption was 95.1%, 96.2%, and 99% for all three actual hospital wastewater samples at the contact time of 180 min, respectively. Consequently, 28°C was found as the best temperature for cefotaxime removal from hospital wastewaters using synthetic membrane containing nanoparticles. The initial concentration of study antibiotic is another key parameter in the adsorption system for the synthetic study of the adsorption and the effective and fast practical application of membranes. Figure 7 shows the impact of this parameter on the cefotaxime adsorption from the hospital wastewater using an optimized synthetic membrane containing nanoparticles at the pH value of 5, contact time of 180 min, temperature of 28°C, and membrane adsorption value of 2.5 mg. As shown in the figure, given the occupancy of sites in the membrane containing nanoparticles, the efficiency of adsorption rate reduces rapidly as the drug concentration in wastewater increases. Adsorption isotherm Adsorption isotherm representing the relationship between adsorbent concentration and adsorption capacity is the most significant parameter in the design of adsorption systems. The adsorption is described as a mass transfer defined by mathematical equations as a process of adsorption equilibrium and adsorption speed. Analysis of adsorption isotherm data is essential for developing the equations that reflect the achieved results used in the system design. Adsorption isotherms are useful quantitative expressions that tell how well an adsorbent can absorb a specific substance [ 21 ]. When both phases are in equilibrium, the equation of adsorption isotherm offers a relationship between the drug concentration in the solution and the quantity of drug absorbed at the solid phase [ 22 ]. This equilibrium analysis gives data, such as the final adsorbent capacity of a specific substance in a single-component system. Besides, the isotherm diagrams of the equilibrium data may be used to derive the isotherm constants required in the mathematical modeling of adsorption systems. As reported in the related literature, although different adsorption isotherm models have been developed, only a few can be utilized to absorb drugs from hospital wastewaters. The adsorption mechanism can be used to describe the adsorption isotherm models [ 23 ]. The Langmuir, Freundlich, and Temkin isotherm models are the three most frequently models suitable for experimental data [ 24 ]. The linear equation of adsorption isotherm for the Langmuir isotherm model is given by (3) [ 25 ]: $$\frac{1}{{\text{q}}_{\text{e}}}=\frac{1}{{\text{k}}_{\text{l}}\times {\text{q}}_{\text{m}\text{a}\text{x}}^{2}}\times \frac{1}{{\text{C}}_{\text{e}}}+\frac{1}{{\text{q}}_{\text{m}\text{a}\text{x}}}$$ 3 where C e , q e, q max , and k L denote the ion equilibrium concentration (mg/L), the quantity of adsorbed ions in equilibrium per gram of absorbent, surface adsorption capacity (mg/g), and adsorption energy (L/g) of Langmuir constants, respectively. Also, R L, whose value denotes the mode and way of adsorption isotherm, is another significant and efficient parameter expressing the main features of the Langmuir equation. The adsorption is undesirable, irreversible, linear, and desirable for R L > 1, R L =0, R L =1, and 0 < R L <1, respectively [ 26 ]. The value of R L is given by: $${\text{R}}_{\text{L}}=\frac{1}{1+{\text{K}}_{\text{L}}{\text{C}}_{\text{o}}}$$ 4 where C o (mg/L) denotes the initial concentration of antibiotics in the aqueous solution. The calculations of adsorption isotherm for cefotaxime were done at 21°C and 37°C because the temperature at which 100% adsorption occurred was 28°C. Based on the results, the maximum adsorption capacity at 0 < R L <1 and the temperatures of 21°C and 37°C is 901.091 mg/g and 1250 mg/g, respectively, indicating the linear and optimal adsorption of drug molecules using the adsorbent (Figs. 8 and 9 ). The Freundlich isotherm model is another frequently utilized isotherm model known as an experimental model that may be used to describe how different adsorbents absorb organic and inorganic substances. The linear equation of adsorption isotherm for Freundlich isotherm model is given by: $${\text{L}\text{n}\text{q}}_{\text{e}}=\text{L}\text{n} {\text{K}}_{\text{f}}+\frac{1}{\text{n}}\text{L}\text{n} {\text{C}}_{\text{e}}$$ 5 where q e , C e , K f , and n denote the equilibrium adsorption capacity (mg/g), ion equilibrium concentration in solution (mg/L), and the Freundlich isotherm model's constants related to adsorption capacity and adsorption intensity, respectively. The results from the cefotaxime adsorption by the adsorbent are represented in Figs. 8 and 9 . In numerous investigations, the value of n has been reported to be between 1 (linear adsorption for all active adsorbent sites) and 10 (a higher degree of interaction between the adsorbent and study material ions) [ 27 ]. The n represents the distribution of adsorbent particles attached to the adsorbent surface. Also, 1/n with values ranging from zero to one represents surface heterogeneity. The surface heterogeneity increases as the value of n approaches zero. Further, 1/n = 0, 0 < 1/n 1 represent the reversible, desirable, and undesirable adsorption, respectively. The constants and parameters of the Freundlich isotherm model were also determined. The value of n in the cefotaxime adsorption from the actual hospital wastewater using the synthesized membrane containing nanoparticles at the temperatures of 21°C and 37°C was estimated to be 6.154 mg/g and 0.374 mg/g, respectively. The value of 1/n reflects the desirable and undesirable cefotaxime adsorption from hospital wastewater at 21°C and at 37°C, respectively. Based on the Freundlich isotherm model, the coefficient of determination (R 2 ) was determined 0.8684 mg/g and 0.7522 mg/g at the temperatures of 21°C and 37°C for the cefotaxime adsorption from hospital wastewater using membrane containing nanoparticles, respectively, indicating the capability of Freundlich isotherm model in describing the isothermal adsorption of the drug (Figs. 10 and 11 ). According to our findings, the cefotaxime adsorption from real hospital wastewaters using synthesized membranes containing nanoparticles is based on the Langmuir (but 21°C) and Freundlich isotherm models. Simulation Studies The Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) is an open-source molecular dynamics simulator that is utilized for computational investigations [ 28 ]. This simulator is one of the first MD codes introduced for particle modeling in various gas, liquid, and solid phases. Multiple force fields and potentials, as well as various boundary conditions, can be used to model different atomic, polymer, biological, metal systems and a combined system composed of these systems. The CFF91force field designed for usage in polymers and organic materials was used to perform calculations. The PES polymeric membrane was prepared using the polymer builder package utilized in the material studio program. To do so, the head and tail points of the monomer were determined, and two strains of PES polymeric membrane with a length of 15 monomers were established using the material studio program, as shown in Figs. 12 and 13 . Similarly, the material studio program was used in preparing the PVP polymer of 25 monomeric chains. A specific morphology was achieved by adding two SiO 2 and TiO 2 nanoparticles to the membrane. The desired percent composition was selected based on the mass percent composition utilized in the experiments. In the material studio program, all of the structures were given to the Amorphous Cell module, and the membrane structure was built using the default density to get the required membrane structure. Figure 14 shows a schematic representation of the achieved membrane. In the LAMMPS molecular dynamics simulator, the equilibrium and associated polymer consistent force field (pcff) coefficients were determined for each atom type [ 29 ]. The cut-off radius for electrostatic was chosen as 12 Aº, and Van der Waals interaction was chosen as 12 Aº. The long-distance electrostatic interactions of the system were calculated using the k-space algorithm [ 30 ]. The temperature and pressure of the system were controlled using a Nose-Hoover thermostat and barostat during the membrane preparation [ 31 ]. Also, the Tdamp and Pdamp values were chosen as 100 and 1000, respectively. In all stages, the time step was set at 1 femtosecond. Of designs established to compress and balance the membrane density, two cases are discussed as follows. In 2000, a 12-step preliminary compression design was introduced [ 28 ], followed by the 12-step annealing and compression design [ 32 ]. Later, in 2011, a general overview was developed based on the 12-step annealing and compression design [ 33 ]. Table 3 presents the characteristics of this 21-step compression/equilibrium general design utilized for density balance. This 21-step design is known as a simulated annealing algorithm where the membrane is periodically cooled and heated to generate the final structure. During compression, the box changes dimensions and overcomes the energy barriers on the study system. As a result, the final density of the system will have a more precise equilibrium value besides its more reliable morphology. Table 3 Compression design. Stage Slow decentralization Time (ps) 1 NVT 600 K 50 2 NVT 300 K 50 3 NPT 0.02Pmax bar, 300 K 50 4 and 5 NVT 600 K, NVT 300 K 50, 100 6 NPT 0.6Pmax bar, 300 K 50 7 and 8 NVT 600 K, NVT 300 K 50, 100 9 NPT Pmax bar, 300 K 50 10 and 11 NVT 600 K, NVT 300 K 50, 100 12 NPT 0.5Pmax bar, 300 K 5 13 and 14 NVT 600 K, NVT 300 K 5, 10 15 NPT 0.1Pmax bar, 300 K 5 16 and 17 NVT 600 K, NVT 300 K 5, 10 18 NPT 0.01Pmax bar, 300 K 5 19 and 20 NVT 600 K, NVT 300 K 5, 10 21 NPT 1 bar, 300 K 100 P max = 40 Gpa The system is fed into NVT and NPT ensembles regularly in this design. At each ensemble, the compaction is carried out by increasing the temperature and pressure of the system. Then, periodic boundary conditions were applied to all three dimensions following the Mont Carlo GCMC simulations using LAMMPS molecular dynamics simulator. The nature of the interactions between the adsorbent and adsorbed molecules was determined using a force field similar to that utilized for the membrane. An in-house program was used to convert the Ceftriaxone molecule's parameters into the files required for LAMMPS simulation. The adsorption coefficients were calculated at three temperatures of 21°C, 28°C, and 37°C and a radiation frequency of 12 Aº by applying the pressure ranging from 1 kPa to 10000 kPa. After balancing the system with 106 steps, additional 106 steps were completed to acquire and evaluate data. Adsorption of cefotaxime molecules on membranes Cefotaxime adsorption isotherms were determined on the membrane surface in the pressures ranging from 1kPa to 10000 kPa, at three different temperatures of 21°C, 28°C, and 37°C, as shown in Figs. 15 – 17 . It was revealed that the adsorption rate of cefotaxime on the membrane at 21°C and 28°C is approximately 2.6 times the adsorption rate at 37°C at a pressure of 1 kPa. Figure 16 . shows the adsorption rate of cefotaxime at a temperature of 21°C. As shown in the figure, at extreme pressure, the membrane adsorption is about 15 molecules per membrane (by adding the percentages from the previous section). At this temperature and pressures near 3000 kPa, the cefotaxime adsorption is constant, indicating that membrane sites are saturated at this pressure and temperature. Figure 17 . shows the adsorption rate of cefotaxime at 28°C. The adsorption curve shows the adsorption rate of 16 cefotaxime molecules at zero pressures so that the adsorption rate should be increased by increasing pressure. Although the membrane seems to exhibit evidence of saturation at a pressure of 9000 kPa, this figure does not show the degree of saturation for this membrane versus cefotaxime at 28°C. When comparing the adsorption diagrams at 21°C and 28°C, it can be found that a similar pattern can be anticipated for cefotaxime adsorption at two temperatures, implying that the adsorption rate of cefotaxime molecules at both temperatures is comparable. Figure 17 . shows the adsorption rate of cefotaxime at 37°C. The adsorption diagram does not follow the same pattern as the previous two temperatures, which is surprising. At 37°C, the adsorption rate of the membrane is much lower than at the previous two temperatures at pressures near zero. At high pressures, a similar pattern can be seen, which means that the membrane follows a similar pattern and is saturated at much lower pressures. Figure 18 shows the morphological analysis of the membrane after maximum cefotaxime is absorbed at the three desired temperatures, in addition to the density of adsorbed cefotaxime as aqua fields or phases in the membrane (distribution of cefotaxime molecules on the membrane). In addition, the occupied membrane sites are shown at all three temperatures, representing the membrane cavities available to trap the cefotaxime molecules. Discussion And Conclusions The present study was conducted to modify the PES polymeric membrane using two nanoparticles for cefotaxime removal from the hospital wastewater. Based on the results from laboratory studies, the pH value, temperature, contact time, and initial concentration improve the effectiveness of the membrane. It can be concluded from diagrams that the maximum cefotaxime adsorption by this membrane containing nanoparticles was realized at the pH value of 5. The quantity of hydrogen ions and the antibiotic ions-adsorbent bond reduces by increasing the pH value. The drug-adsorption equilibrium time was 180 min, where 100% adsorption occurred. The initial concentration of cefotaxime was another important parameter affecting the adsorption kinetics and the effective and fast practical application of membranes. The results showed that the adsorption rate decreases by increasing drug concentration, which might be because of membrane fouling and adsorption sites' saturation. The results from the analysis of adsorption kinetics using a synthetic membrane indicated that the quasi first-order model could describe the kinetic behavior of adsorption due to higher computational value than the value obtained from laboratory data (q e. exp ) and also the determined R 2 value using the quasi first-order model. The Langmuir isotherm model-based adsorption capacity calculations at temperatures of 21 and 37°C confirmed that 0 < RL < 1 of the adsorption means that the best adsorption of drug molecules using the adsorbent follows a linear pattern. The constants and parameters of the Freundlich isotherm model, as well as the value of n in cefotaxime adsorption in real hospital wastewater using the synthetic membrane containing nanoparticles, revealed that the cefotaxime adsorption in hospital wastewater was desirable and undesirable at 21°C and 37°C, respectively. The value achieved for R 2 using the Freundlich isotherm model for cefotaxime adsorption from hospital wastewater reflected the significant capability of this model in describing the adsorption isothermal of the drug. Examining the simulation diagrams with the LAMMPS molecular dynamics simulator confirmed the laboratory data and offered further data regarding the membrane morphology shown in the figures and diagram. Declarations Funding: Not applicable Conflicts of interest/Competing interests: Not applicable Availability of data and material (data transparency): All data and calculations can be presented and read if needed. Code availability (software application or custom code): Since open-source software was utilized in this study, the data about it is also available to academics. Authors' contributions : Study concept and design: Zeinab Nikfarjam, Mohammad Momen Heravi, Mohammad Reza Bozorgmehr Acquisition of data and Analysis and interpretation of data: Mohammad Momen Heravi, Zeinab Nikfarjam (Experiments), Zeinab Nikfarjam, Mohammad Reza Bozorgmehr (Computational) Drafting of the manuscript : Zeinab Nikfarjam, Mohammad Momen Heravi, Mohammad Reza Bozorgmehr Study supervision: Mohammad Momen Heravi, Mohammad Reza Bozorgmehr References Poynton HC, Robinson WE (2018) Contaminants of emerging concern, with an emphasis on nanomaterials and pharmaceuticals. Green Chemistry. Elsevier, pp 291–315 La Farre M, Pérez S, Kantiani L, Barceló D (2008) Fate and toxicity of emerging pollutants, their metabolites and transformation products in the aquatic environment. 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Elsevier Lee H, Venable RM, MacKerell Jr AD, Pastor RW (2008) Molecular dynamics studies of polyethylene oxide and polyethylene glycol: hydrodynamic radius and shape anisotropy. Biophys J 95(4):1590–1599 Gulnaz O, Sahmurova A, Kama S (2011) Removal of Reactive Red 198 from aqueous solution by Potamogeton crispus. Chem Eng J 174(2–3):579–585 Yadav SK, Singh DK, Sinha S (2014) Chemical carbonization of papaya seed originated charcoals for sorption of Pb (II) from aqueous solution. J Environ Chem Eng 2(1):9–19 Febrianto J, Kosasih AN, Sunarso J, Ju YH, Indraswati N, Ismadji S (2009) Equilibrium and kinetic studies in adsorption of heavy metals using biosorbent: a summary of recent studies. J Hazard Mater 162(2–3):616–645 Mall ID, Srivastava VC, Agarwal NK, Mishra IM (2005) Adsorptive removal of malachite green dye from aqueous solution by bagasse fly ash and activated carbon-kinetic study and equilibrium isotherm analyses. Colloids Surf A 264(1–3):17–28 Ho YS (2006) Isotherms for the sorption of lead onto peat: comparison of linear and non-linear methods.Polish journal of environmental studies, 15(1) Delle Site A (2001) Factors affecting sorption of organic compounds in natural sorbent/water systems and sorption coefficients for selected pollutants. A review. J Phys Chem Ref Data 30(1):187–439 Hofmann D, Fritz L, Ulbrich J, Schepers C, Böhning M (2000) Detailed-atomistic molecular modeling of small molecule diffusion and solution processes in polymeric membrane materials. Macromol Ther Simul 9(6):293–327 Plimpton S (1995) Fast parallel algorithms for short-range molecular dynamics. J Comput Phys 117(1):1–19 Maple JR, Thacher TS, Dinur U, Hagler AT (1990) Biosym force field research results in new techniques for the extraction of inter-and intramolecular forces. Chem Des Automat News 5(9):5–10 Hockney RW, Eastwood JW (1989) The Particle-Mesh force calculation. Computer Simulation Using Particles, Adam Hilger, Bristol and New York, NY, USA, 120–165 Hoover WG (1985) Canonical dynamics: Equilibrium phase-space distributions. Phys Rev A 31(3):1695 Karayiannis NC, Mavrantzas VG, Theodorou DN (2004) Detailed atomistic simulation of the segmental dynamics and barrier properties of amorphous poly (ethylene terephthalate) and poly (ethylene isophthalate). Macromolecules 37(8):2978–2995 Larsen GS, Lin P, Hart KE, Colina CM (2011) Molecular simulations of PIM-1-like polymers of intrinsic microporosity. Macromolecules 44(17):6944–6951 Tables Table 1 is available in the Supplemental Files section. Supplementary Files Table1.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-1494699","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":95628621,"identity":"5b3802c9-6dd8-4728-ba35-b166441bdae8","order_by":0,"name":"Zeinab Nikfarjam","email":"data:image/png;base64,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","orcid":"","institution":"Islamic Azad University Mashhad Branch","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Zeinab","middleName":"","lastName":"Nikfarjam","suffix":""},{"id":95628622,"identity":"57fadd83-e244-4f3c-8d91-705f41375257","order_by":1,"name":"Mohammad Momen Heravi","email":"","orcid":"","institution":"Islamic Azad University Mashhad Branch","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Mohammad","middleName":"Momen","lastName":"Heravi","suffix":""},{"id":95628623,"identity":"a407ab23-89c3-4a3c-9f23-a0b57a60053c","order_by":2,"name":"Mohammad Reza Bozorgmehr","email":"","orcid":"","institution":"Islamic Azad University Mashhad Branch","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Mohammad","middleName":"Reza","lastName":"Bozorgmehr","suffix":""}],"badges":[],"createdAt":"2022-03-27 16:03:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-1494699/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-1494699/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":19992774,"identity":"34769382-c210-4d64-bb0b-c1062ec65cce","added_by":"auto","created_at":"2022-04-05 19:41:33","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":31419,"visible":true,"origin":"","legend":"\u003cp\u003eAFM image captured from a synthetic membrane.\u003c/p\u003e\u003cp\u003e\u0026nbsp;\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/15b24e7655d728cd36865527.jpg"},{"id":19993665,"identity":"f4fa8291-bc9f-4891-9f3a-f0152f75f6b7","added_by":"auto","created_at":"2022-04-05 19:46:33","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":26437,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR result for the synthetic membrane.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/4a6663da00c22492586db438.png"},{"id":19993666,"identity":"0413e0b2-c1ad-47b3-9b37-79d517788b44","added_by":"auto","created_at":"2022-04-05 19:46:33","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":963153,"visible":true,"origin":"","legend":"\u003cp\u003eImpact of pH value on cefotaxime adsorption.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/f03ec3c362022120de73195c.jpg"},{"id":19994259,"identity":"06851375-e05b-4905-b6f0-ab1f7cf65d44","added_by":"auto","created_at":"2022-04-05 19:56:33","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":962681,"visible":true,"origin":"","legend":"\u003cp\u003eImpact of contact time on the cefotaxime adsorption.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/3a567dca252ef71653c96a4d.jpg"},{"id":19992775,"identity":"b50ce514-9744-4d33-93b3-b87b02b53a83","added_by":"auto","created_at":"2022-04-05 19:41:33","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":957917,"visible":true,"origin":"","legend":"\u003cp\u003eImpact of temperature on the cefotaxime adsorption.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/d715fc312ea486ee2ce2ca3d.jpg"},{"id":19992779,"identity":"1d5f2573-5f7f-419d-9c7d-c2e6147c0907","added_by":"auto","created_at":"2022-04-05 19:41:33","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":984309,"visible":true,"origin":"","legend":"\u003cp\u003eImpact of initial drug concentration on cefotaxime adsorption.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"fig7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/1fd5adf4ca5df63e697e3986.jpg"},{"id":19994261,"identity":"67b307ed-48c3-4f0a-baaa-c2a8b0f3b54f","added_by":"auto","created_at":"2022-04-05 19:56:33","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":248534,"visible":true,"origin":"","legend":"\u003cp\u003eLangmuir isotherm model for cefotaxime adsorption from real hospital wastewater using synthetic membrane containing nanoparticles at the temperature of 21°C.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig8.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/628874f26b2853bff148e631.jpg"},{"id":19994573,"identity":"5164cd9e-3b18-41ba-980d-4dac4960cb74","added_by":"auto","created_at":"2022-04-05 20:01:33","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":243184,"visible":true,"origin":"","legend":"\u003cp\u003eLangmuir isotherm model for cefotaxime adsorption from real hospital wastewater using synthesized membrane containing nanoparticles at the temperature of 37°C, R\u003csup\u003e2\u003c/sup\u003e=0.9734, and y=0.0008x+0.0008.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig9.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/4a88d2bfd787927095c6976f.jpg"},{"id":19993946,"identity":"e7a2f5c0-5e5d-4539-87d6-00b919282e29","added_by":"auto","created_at":"2022-04-05 19:51:33","extension":"jpg","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":212139,"visible":true,"origin":"","legend":"\u003cp\u003eFreundlich isotherm model for the cefotaxime adsorption from real hospital wastewater using synthetic membrane containing nanoparticles at the temperature of 21°C, R\u003csup\u003e2\u003c/sup\u003e=0.8646, and y=0.1625x+6.4727.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig10.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/8739026ea8606048d220fc8e.jpg"},{"id":19993951,"identity":"e393e0f6-6857-4187-a793-bad7ff786919","added_by":"auto","created_at":"2022-04-05 19:51:33","extension":"jpg","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":207556,"visible":true,"origin":"","legend":"\u003cp\u003eFreundlich isotherm model for the cefotaxime adsorption from real hospital wastewater using synthetic membrane containing nanoparticles at the temperature of 37°C, R\u003csup\u003e2\u003c/sup\u003e=0.7522, and y=2.6734x+7.7457.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig11.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/bfb092ca91a9fa3389ad6d34.jpg"},{"id":19992784,"identity":"aa246f5c-7cef-4377-9e80-a29584140c24","added_by":"auto","created_at":"2022-04-05 19:41:33","extension":"jpg","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":158812,"visible":true,"origin":"","legend":"\u003cp\u003eThe skeleton of polyethersulfone (PES) polymeric membrane with a purple stripe.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"fig12.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/565c06f58761c675217255fb.jpg"},{"id":19992787,"identity":"907bc186-9b40-469f-9d6d-cdee13f3f513","added_by":"auto","created_at":"2022-04-05 19:41:33","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":658300,"visible":true,"origin":"","legend":"\u003cp\u003eThe skeleton of Polyvinylpyrrolidone (PVP) polymeric membrane with a purple stripe.\u0026nbsp;\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"fig13.png","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/0bf1a44a1f59678f91db2c75.png"},{"id":19993674,"identity":"046ea1ba-6963-4510-81b0-51b921a2268f","added_by":"auto","created_at":"2022-04-05 19:46:33","extension":"jpg","order_by":14,"title":"Figure 14","display":"","copyAsset":false,"role":"figure","size":166667,"visible":true,"origin":"","legend":"\u003cp\u003eA schematic representation of the achieved membrane.\u003c/p\u003e","description":"","filename":"fig14.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/ae100e9d07f46c84738facf8.jpg"},{"id":19992790,"identity":"5fd6b996-7d9c-437b-9234-34590eec1572","added_by":"auto","created_at":"2022-04-05 19:41:34","extension":"jpg","order_by":15,"title":"Figure 15","display":"","copyAsset":false,"role":"figure","size":279635,"visible":true,"origin":"","legend":"\u003cp\u003eCefotaxime adsorption isotherm on the membrane at 21°C.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig15.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/140cd48bd8e0e0183caea013.jpg"},{"id":19993676,"identity":"5692f094-b669-4bcb-ac6e-c141f85423e3","added_by":"auto","created_at":"2022-04-05 19:46:33","extension":"jpg","order_by":16,"title":"Figure 16","display":"","copyAsset":false,"role":"figure","size":325589,"visible":true,"origin":"","legend":"\u003cp\u003eCefotaxime adsorption isotherm on the membrane at 28°C.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig16.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/60fb0d71c1c3aa5e9fc60b0f.jpg"},{"id":19993952,"identity":"a5b36368-8352-40da-a081-705a1b7374e8","added_by":"auto","created_at":"2022-04-05 19:51:33","extension":"jpg","order_by":17,"title":"Figure 17","display":"","copyAsset":false,"role":"figure","size":299264,"visible":true,"origin":"","legend":"\u003cp\u003eCefotaxime adsorption isotherm on the membrane at 37°C.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig17.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/8a816befdd98233228eed761.jpg"},{"id":19993670,"identity":"49032ac5-3da6-4428-8b4f-05ad47dc4d14","added_by":"auto","created_at":"2022-04-05 19:46:33","extension":"png","order_by":18,"title":"Figure 18","display":"","copyAsset":false,"role":"figure","size":78196,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of the absorbed cefotaxime molecules. The density of cefotaxime molecules embedded in the membrane cavities is shown in blue.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Fig18.png","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/d58fc053a709aa55934a6004.png"},{"id":19992791,"identity":"578f9135-7631-4f17-9fc6-334bff4b5afe","added_by":"auto","created_at":"2022-04-05 19:41:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":551614,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/3468d174-81a6-4513-9ba5-5ce97373abc5.pdf"},{"id":19992772,"identity":"92ddf872-95c9-42ad-9cab-b8bff668547c","added_by":"auto","created_at":"2022-04-05 19:41:33","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":33964,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-1494699/v1/a8e781747a09248843601976.docx"}],"financialInterests":"","formattedTitle":"\u003cp\u003eRemoval of Cefotaxime Antibiotics from Hospital Wastewater using TiO\u003csub\u003e2\u003c/sub\u003e and SiO\u003csub\u003e2\u003c/sub\u003e Nanoparticles-Modified Polyethersulfone Membrane: Experimental and Computational Study\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eBecause of the potential negative environmental consequences of emerging contaminants, they have caught the attention of academics and the international community. Accordingly, several attempts have been undertaken for reflecting the significance of contaminant emissions into various environments and adopting all the actions or steps necessary. However, improving present water and wastewater treatment technologies and integrating them into a complete and cyclical water management system is a long-term solution to this problem [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Antibiotics are the most alarming of all emerging contaminants, given their contribution to the development of resistant bacteria, even at low concentrations [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. It seems that antibiotics do not kill bacteria at low concentrations, but the bacteria respond to mutations by developing genes to defend themselves from antibiotics. It should be mentioned that antibiotics are capable of replicating these genes in different bacterial strains [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThese contaminants need to be regarded as a challenge because the long-term consequences of these medications have yet to be explored since the environment is likely to encounter numerous resistant bacteria with no unique, efficient behaviors in the next few years. According to the World Bank, by 2050, the resistant bacteria will have killed 10\u0026nbsp;million individuals per year and forced 28\u0026nbsp;million individuals to fall into extreme poverty [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFurther antibiotics usage leaves considerable residues entering the environment, infiltrating the ecosystem either directly or indirectly. In a variety of matrices, human and veterinary specific antibiotic residues have been found. According to the literature on the significant impact of antibiotic usage, antibiotic exposure has been demonstrated to affect the survival and growth of aquatic organisms significantly. Antibiotics are mostly acquired in natural waters (i.e., rainwater, seawater, and river water, and groundwater) from the wastewaters of municipal wastewater treatment facilities and pharmaceutical manufacturing facilities. The antibiotics discharged into the natural environment are expected to be propriety for municipal wastewater treatment facilities. Hence, pharmaceutical chemicals, particularly antibiotics, are identified as developing environmental pollutants classed as substances resistant to bioaccumulation, reflecting the antibiotics as toxic and hazardous chemicals [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMembrane processes are one of the most practical techniques utilized to separate medications, such as antibiotics since they are more efficient and less expensive. Emerging membrane technologies hold great potential for removing pollutants, such as antibiotics. The most significant maintenance characteristics of nanofiltration as a membrane separation technology for multivalent ions and organic substances at relatively low operating pressures make it appealing. The membrane separation technology is frequently utilized in drinking water quality monitoring, wastewater treatment, and industrial applications [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn a membrane process, there are usually two phases (permeability and selectivity) physically separated by a third phase (membrane). However, all membrane materials possess one common feature, i.e., they allow to flow of various materials through them selectively. That is to say, a membrane is a tool allowing materials to be separated concerning their molecular sizes [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eGenerally, membranes can be classified into two classes biological and synthetic. In addition, the types of constituent materials and manufacturing technology utilized to produce the membrane might result in various structures [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe polymer types are chosen for producing polymeric membranes concerning different factors, including thermal, chemical, and mechanical characteristics of polymers and parameters affecting the permeability of polymers, the challenge that is prominent significantly in producing porous membranes. For example, polysulfone (PSU) and polyethersulfone (PES) polymeric membranes are frequently utilized as raw materials to produce ultrafiltration and microfiltration membranes due to their high mechanical, thermal, and chemical endurance and their homogeneous characteristics. In general, availability, ease of processing, and optimized selectivity features of this polymer type makes it the dominant polymer in the production of membranes [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePolymeric membranes have a hydrophobic nature decreasing the water permeability and sensitivity to fouling and sedimentation, particularly the organic matter deposition. Thus, the structure of membranes is modified for enhancing their hydrophilicity, resulting in increased water flux, reversibility, and fouling resistance. Hence, different techniques are utilized for improving the membranes and increasing their hydrophilicity, characterized as a surface coating. Surface grafting and different surface modification techniques can change the surface chemistry enhance the membrane surface hydrophilicity and membrane bending. The employment of hydrophilic polymers combined with hydrophobic polymers, such as PES polymeric membrane, may result in the modified characteristics and morphology of the membranes. The employment of amphiphilic copolymers may result in the enhanced surface hydrophilicity and even bulk membranes. Also, mineral nanoparticles may enhance membrane efficiency because of some factors, such as microscopic particles, extended surface area, and intense activities [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOne field of study in extensive membrane separation technology is nanomaterials that improve low fouling or antifouling membranes [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Accordingly, in this study, two different nanoparticles were utilized at the same time.\u003c/p\u003e \u003cp\u003eIn the present work, the MD simulations were also utilized. In summary, a molecular simulation is an important tool used to study polymer science, which can be utilized for polymer systems with a known configuration, and its characteristics can be determined at the molecular/micro scales. The MD simulations allow academics to evaluate the impact of systemic changes on the macroscopic characteristics of a system. Given the inability of polymer systems to show materials' behaviors at the atomic scale, the laboratory study of polymer systems is not essential for gaining a thorough knowledge of many phenomena, highlighting the significant contribution of molecular simulations in predicting and designing polymer systems to justify the effective laboratory techniques. Among the simulation techniques, the MD simulation technique is significantly effective in studying the polymer systems [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eEach MD simulation consists of three stages: 1) Determining a series of initial conditions (initial position and speed of all particles), 2) selecting a proper potential function for describing the interactions between particles, and 3) the study of system changes over time by numerically integrating a series of classical Newtonian equations of motion for all system particles concerning the periodic boundary conditions, and managing temperature and pressure for the physical replication of the thermodynamic ensemble [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eA variety of polymer solutions are utilized in different industrial applications, such as adhesives, dyes, coatings, polymerization, fiber membrane manufacturing, and so on. The molecular simulation techniques can give detailed data about the behaviors of chains in polymer solutions, predict the biomolecules' structures and chemical interactions, as well as the polymeric material behaviors, and recognize a variety of underlying molecular characteristics of membranes and processes [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/p\u003e"},{"header":"Materials And Methods","content":"\u003cdiv class=\"Section2\" id=\"Sec3\"\u003e\n \u003ch2\u003eExperiment:\u003c/h2\u003e\n \u003cp\u003eDifferent materials were used in the present study, including PES polymeric membrane as the primary polymer, polyvinylpyrrolidone (PVP) as an auxiliary polymer for porosity regulation, dimethylacetamide (DMA) as an organic solvent, SiO\u003csub\u003e2\u003c/sub\u003e and TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles, and distilled water as anti-solvent (Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e presents the chemical structures of used materials). In addition, a UP400s-ultrasonic device (Sound Technology Development Ltd, Iran) was utilized in the coagulation technique for solution uniformization during the membrane synthesis. Furthermore, Shing Sing magnetic stirrer (Germany) with a variable round of 100\u0026ndash;800 rpm was utilized for bubble removal from the solvent, besides a film applicator for filtrating the prepared solution.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec4\"\u003e\n \u003ch2\u003eMembrane preparation method\u003c/h2\u003e\n \u003cp\u003eThe weight ratios of 25% PES, 5% PVP, 1% SiO\u003csub\u003e2\u003c/sub\u003e, and 2% TiO\u003csub\u003e2\u003c/sub\u003e were considered for membrane production. First, two separate containers were used to prepare the solutions, one containing additive and auxiliary polymer, and 20% of the required solvent was placed on a magnetic stirrer. The other containing nanoparticles and the remaining solvent were sonicated at the minimum temperature in the ultrasonic device. Stirring was continued for a long time following the preparation of a homogeneous solution and the addition of the contents of the first container, and then the bubbles were allowed to escape completely after the necessary period of time. Finally, a film applicator of a specific thickness was used to transfer the solution to the glass. Next, a coagulation bath was used for preparing the membrane that was then transferred to another distilled water container for solvent removal. In this phase, any quantity of PVP that can be dissolved in water is removed from the film by dissolving it in water. The scanning electron microscope (SEM) and atomic force microscope (AFM) (Figs. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e) imaging techniques were used to capture an image from the adsorbent surface structure for morphological analysis of the physical membrane surface. The number of adsorption-needed sites grows as the heterogeneous adsorbent surface is confirmed. The adsorption is also enhanced by the pores at the adsorbent surface. The synthetic membrane was characterized using the Fourier-transform infrared (FTIR) spectroscopy technique (Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eThe membrane hydrophilicity was determined by conducting a contact angle test (Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). The membrane surface-water contact angle decreases by adding nanoparticles to the polymer solution, indicating that hydrophilicity of the membrane containing nanoparticles increases in comparison with the plain polymeric membrane.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003cdiv align=\"left\" class=\"colspec\"\u003e\u003cbr\u003e\u003c/div\u003e\u0026nbsp;\u003ctable border=\"1\" id=\"Tab2\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eThe result of the contact angel test on the synthetic membrane.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"2\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003emembrane\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eContact angel\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePES\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e68\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePES TiO\u003csub\u003e2\u003c/sub\u003e \u0026ndash; SiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e57.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec5\"\u003e\n \u003ch2\u003eImpact of various parameters on the cefotaxime adsorption\u003c/h2\u003e\n \u003cdiv class=\"Section3\" id=\"Sec6\"\u003e\n \u003ch2\u003epH effect\u003c/h2\u003e\n \u003cp\u003eTests were conducted at the pH values of 5, 7, and typical ones for examining the impact of pH on the adsorption. The pH value was regulated using sodium hydroxide and 0.1 M hydrochloric acid. The first was to complete adsorption in three wastewater samples containing cefotaxime antibiotics. After that, samples were taken at various pH values, and the quantity of drugs left in the wastewater was recorded.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec7\"\u003e\n \u003ch2\u003eImpact of contact time and temperature on adsorption\u003c/h2\u003e\n \u003cp\u003eThe tests were repeated at three 60, 120, and 180 seconds contact times, three 21\u0026deg;C, 28\u0026deg;C, and 37\u0026deg;C temperatures, and the constant pH value of 5 to examine the impact of contact time and temperature on the adsorption rate by keeping the adsorbent constant from the prepared membrane containing nanoparticles. The solution containing the left drug was then collected, and a spectrophotometer was then used to read and record its quantity.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec8\"\u003e\n \u003ch2\u003eImpact of initial drug concentration in wastewater\u003c/h2\u003e\n \u003cp\u003eTests were conducted at 10, 25, and 50 ppm by keeping constant other parameters to examine the impact of the initial concentration of cefotaxime on the adsorption. The quantity of drugs left in the solution was then measured.\u003c/p\u003e\n \u003cdiv class=\"Section3\" id=\"Sec9\"\u003e\n \u003ch2\u003eDetermining the percent removal and adsorption capacity\u003c/h2\u003e\n \u003cp\u003eThe percent antibiotic elimination (R) and the adsorption capacity (q\u003csub\u003ee\u003c/sub\u003e) can be calculated as follows:\u003c/p\u003e\n \u003cdiv class=\"Equation\" id=\"Equ1\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e$$\\text{R}=\\frac{(\\text{C}\\text{o}-\\text{C}\\text{e})}{\\text{C}\\text{o}}\\times 100$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\n \u003c/div\u003e\n \u003cdiv class=\"Equation\" id=\"Equ2\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equ2\" name=\"EquationSource\"\u003e$$\\text{q}\\text{e}=\\frac{(\\text{C}\\text{o}-\\text{C}\\text{e})}{\\text{w}}\\times \\text{V}$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e2\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003ewhere C\u003csub\u003eo\u003c/sub\u003e, C\u003csub\u003ee\u003c/sub\u003e, V, w, R, qe denote the initial and final concentrations (mg/L) of antibiotic molecules in the solution, solution volume (L), solution mass (gr), removal efficiency (%), and adsorption capacity (mg/g), respectively. Finally, adsorption isotherms, corresponding associations, and the governing equations were evaluated. Then, for laboratory result confirmation, the Monte Carlo calculations were performed.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec10\"\u003e\n \u003ch2\u003eData analysis\u003c/h2\u003e\n \u003cp\u003eThe pH effect on the cefotaxime adsorption using optimized synthetic membrane containing nanoparticles at the contact time of 120 min, the temperature of 28\u0026deg;C, and the membrane adsorption value of 2.5 mg is shown in Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e. As shown in the figure, because the concentration of hydrogen ions is low at the pH value of 7, and hydrogen ions are absorbed rather than medicinal ions, the minimum adsorption rate is at this pH value. Adsorption efficiency reduces as the pH value increases, leading to achieving the minimum percent adsorption at the pH value of 7. The type and ionic state of the adsorbent causative agents significantly affect the pH value of antibiotic adsorption. Consequently, it can be concluded that the pH value affects the adsorption equilibrium; thus, the pH value of 5 was chosen as the best pH, with the maximum cefotaxime adsorption by a membrane containing nanoparticles. The quantity of hydrogen ions and the antibiotic ions-adsorbent bond reduces by increasing the pH value. This most is likely due to an increase in inadequate retention time for the synthesis of active hydroxyl radicals and adequate time for the hydroxyl radical reaction to the cefotaxime molecules.\u003c/p\u003e\n \u003cp\u003eThe impact of contact time on the cefotaxime adsorption using optimized synthetic membrane containing nanoparticles at the pH value of 5, the temperature of 28\u0026deg;C, and the membrane adsorption value of 2.5 mg is shown in Fig. \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e. As shown in the figure, the fast adsorption in the contact time of 120 min is due to the abundant surface sites for cefotaxime adsorption on synthetic membranes containing nanoparticles. When the external sites are saturated after 120 min, further time is required for the adsorption to occur at the internal active sites. Since practically, all internal and external sites are saturated after 180 min, and the adsorption process achieves a state of equilibrium, so the best time is 180 min for the maximum drug adsorption (100% adsorption).\u003c/p\u003e\n \u003cp\u003eThe impact of temperature on the cefotaxime adsorption using optimized synthetic membrane containing nanoparticles at the pH value of 5, contact time of 180 min, and membrane adsorption value of 2.5 mg is shown in Fig. \u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e. As shown in the figure, the efficiency of cefotaxime adsorption increases at the temperature of 28\u0026deg;C. The cefotaxime adsorption was 95.1%, 96.2%, and 99% for all three actual hospital wastewater samples at the contact time of 180 min, respectively. Consequently, 28\u0026deg;C was found as the best temperature for cefotaxime removal from hospital wastewaters using synthetic membrane containing nanoparticles.\u003c/p\u003e\n \u003cp\u003eThe initial concentration of study antibiotic is another key parameter in the adsorption system for the synthetic study of the adsorption and the effective and fast practical application of membranes. Figure \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e shows the impact of this parameter on the cefotaxime adsorption from the hospital wastewater using an optimized synthetic membrane containing nanoparticles at the pH value of 5, contact time of 180 min, temperature of 28\u0026deg;C, and membrane adsorption value of 2.5 mg. As shown in the figure, given the occupancy of sites in the membrane containing nanoparticles, the efficiency of adsorption rate reduces rapidly as the drug concentration in wastewater increases.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec11\"\u003e\n \u003ch2\u003eAdsorption isotherm\u003c/h2\u003e\n \u003cp\u003eAdsorption isotherm representing the relationship between adsorbent concentration and adsorption capacity is the most significant parameter in the design of adsorption systems. The adsorption is described as a mass transfer defined by mathematical equations as a process of adsorption equilibrium and adsorption speed. Analysis of adsorption isotherm data is essential for developing the equations that reflect the achieved results used in the system design. Adsorption isotherms are useful quantitative expressions that tell how well an adsorbent can absorb a specific substance [\u003cspan class=\"CitationRef\"\u003e21\u003c/span\u003e]. When both phases are in equilibrium, the equation of adsorption isotherm offers a relationship between the drug concentration in the solution and the quantity of drug absorbed at the solid phase [\u003cspan class=\"CitationRef\"\u003e22\u003c/span\u003e]. This equilibrium analysis gives data, such as the final adsorbent capacity of a specific substance in a single-component system. Besides, the isotherm diagrams of the equilibrium data may be used to derive the isotherm constants required in the mathematical modeling of adsorption systems.\u003c/p\u003e\n \u003cp\u003eAs reported in the related literature, although different adsorption isotherm models have been developed, only a few can be utilized to absorb drugs from hospital wastewaters. The adsorption mechanism can be used to describe the adsorption isotherm models [\u003cspan class=\"CitationRef\"\u003e23\u003c/span\u003e]. The Langmuir, Freundlich, and Temkin isotherm models are the three most frequently models suitable for experimental data [\u003cspan class=\"CitationRef\"\u003e24\u003c/span\u003e]. The linear equation of adsorption isotherm for the Langmuir isotherm model is given by (3) [\u003cspan class=\"CitationRef\"\u003e25\u003c/span\u003e]:\u003c/p\u003e\n \u003cdiv class=\"Equation\" id=\"Equ3\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equ3\" name=\"EquationSource\"\u003e$$\\frac{1}{{\\text{q}}_{\\text{e}}}=\\frac{1}{{\\text{k}}_{\\text{l}}\\times {\\text{q}}_{\\text{m}\\text{a}\\text{x}}^{2}}\\times \\frac{1}{{\\text{C}}_{\\text{e}}}+\\frac{1}{{\\text{q}}_{\\text{m}\\text{a}\\text{x}}}$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e3\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003ewhere C\u003csub\u003ee\u003c/sub\u003e, q\u003csub\u003ee,\u003c/sub\u003e q\u003csub\u003emax\u003c/sub\u003e, and k\u003csub\u003eL\u003c/sub\u003e denote the ion equilibrium concentration (mg/L), the quantity of adsorbed ions in equilibrium per gram of absorbent, surface adsorption capacity (mg/g), and adsorption energy (L/g) of Langmuir constants, respectively. Also, R\u003csub\u003eL,\u003c/sub\u003e whose value denotes the mode and way of adsorption isotherm, is another significant and efficient parameter expressing the main features of the Langmuir equation. The adsorption is undesirable, irreversible, linear, and desirable for R\u003csub\u003eL\u003c/sub\u003e\u0026gt; 1, R\u003csub\u003eL\u003c/sub\u003e=0, R\u003csub\u003eL\u003c/sub\u003e=1, and 0\u0026thinsp;\u0026lt;\u0026thinsp;R\u003csub\u003eL\u003c/sub\u003e\u0026lt;1, respectively [\u003cspan class=\"CitationRef\"\u003e26\u003c/span\u003e]. The value of R\u003csub\u003eL\u003c/sub\u003e is given by:\u003c/p\u003e\n \u003cdiv class=\"Equation\" id=\"Equ4\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equ4\" name=\"EquationSource\"\u003e$${\\text{R}}_{\\text{L}}=\\frac{1}{1+{\\text{K}}_{\\text{L}}{\\text{C}}_{\\text{o}}}$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e4\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003ewhere C\u003csub\u003eo\u003c/sub\u003e (mg/L) denotes the initial concentration of antibiotics in the aqueous solution.\u003c/p\u003e\n \u003cp\u003eThe calculations of adsorption isotherm for cefotaxime were done at 21\u0026deg;C and 37\u0026deg;C because the temperature at which 100% adsorption occurred was 28\u0026deg;C. Based on the results, the maximum adsorption capacity at 0\u0026thinsp;\u0026lt;\u0026thinsp;R\u003csub\u003eL\u003c/sub\u003e \u0026lt;1 and the temperatures of 21\u0026deg;C and 37\u0026deg;C is 901.091 mg/g and 1250 mg/g, respectively, indicating the linear and optimal adsorption of drug molecules using the adsorbent (Figs. \u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e and \u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eThe Freundlich isotherm model is another frequently utilized isotherm model known as an experimental model that may be used to describe how different adsorbents absorb organic and inorganic substances. The linear equation of adsorption isotherm for Freundlich isotherm model is given by:\u003c/p\u003e\n \u003cdiv class=\"Equation\" id=\"Equ5\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equ5\" name=\"EquationSource\"\u003e$${\\text{L}\\text{n}\\text{q}}_{\\text{e}}=\\text{L}\\text{n} {\\text{K}}_{\\text{f}}+\\frac{1}{\\text{n}}\\text{L}\\text{n} {\\text{C}}_{\\text{e}}$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e5\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003ewhere q\u003csub\u003ee\u003c/sub\u003e, C\u003csub\u003ee\u003c/sub\u003e, K\u003csub\u003ef\u003c/sub\u003e, and n denote the equilibrium adsorption capacity (mg/g), ion equilibrium concentration in solution (mg/L), and the Freundlich isotherm model\u0026apos;s constants related to adsorption capacity and adsorption intensity, respectively.\u003c/p\u003e\n \u003cp\u003eThe results from the cefotaxime adsorption by the adsorbent are represented in Figs. \u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e and \u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003e. In numerous investigations, the value of n has been reported to be between 1 (linear adsorption for all active adsorbent sites) and 10 (a higher degree of interaction between the adsorbent and study material ions) [\u003cspan class=\"CitationRef\"\u003e27\u003c/span\u003e]. The n represents the distribution of adsorbent particles attached to the adsorbent surface. Also, 1/n with values ranging from zero to one represents surface heterogeneity. The surface heterogeneity increases as the value of n approaches zero. Further, 1/n\u0026thinsp;=\u0026thinsp;0, 0\u0026thinsp;\u0026lt;\u0026thinsp;1/n\u0026thinsp;\u0026lt;\u0026thinsp;1, 1/n\u0026thinsp;\u0026gt;\u0026thinsp;1 represent the reversible, desirable, and undesirable adsorption, respectively.\u003c/p\u003e\n \u003cp\u003eThe constants and parameters of the Freundlich isotherm model were also determined. The value of n in the cefotaxime adsorption from the actual hospital wastewater using the synthesized membrane containing nanoparticles at the temperatures of 21\u0026deg;C and 37\u0026deg;C was estimated to be 6.154 mg/g and 0.374 mg/g, respectively. The value of 1/n reflects the desirable and undesirable cefotaxime adsorption from hospital wastewater at 21\u0026deg;C and at 37\u0026deg;C, respectively. Based on the Freundlich isotherm model, the coefficient of determination (R\u003csup\u003e2\u003c/sup\u003e) was determined 0.8684 mg/g and 0.7522 mg/g at the temperatures of 21\u0026deg;C and 37\u0026deg;C for the cefotaxime adsorption from hospital wastewater using membrane containing nanoparticles, respectively, indicating the capability of Freundlich isotherm model in describing the isothermal adsorption of the drug (Figs. \u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003e and \u003cspan class=\"InternalRef\"\u003e11\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eAccording to our findings, the cefotaxime adsorption from real hospital wastewaters using synthesized membranes containing nanoparticles is based on the Langmuir (but 21\u0026deg;C) and Freundlich isotherm models.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec12\"\u003e\n \u003ch2\u003eSimulation Studies\u003c/h2\u003e\n \u003cp\u003eThe Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) is an open-source molecular dynamics simulator that is utilized for computational investigations [\u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e]. This simulator is one of the first MD codes introduced for particle modeling in various gas, liquid, and solid phases. Multiple force fields and potentials, as well as various boundary conditions, can be used to model different atomic, polymer, biological, metal systems and a combined system composed of these systems. The CFF91force field designed for usage in polymers and organic materials was used to perform calculations. The PES polymeric membrane was prepared using the polymer builder package utilized in the material studio program. To do so, the head and tail points of the monomer were determined, and two strains of PES polymeric membrane with a length of 15 monomers were established using the material studio program, as shown in Figs. \u003cspan class=\"InternalRef\"\u003e12\u003c/span\u003e and \u003cspan class=\"InternalRef\"\u003e13\u003c/span\u003e.\u003c/p\u003e\n \u003cp\u003eSimilarly, the material studio program was used in preparing the PVP polymer of 25 monomeric chains. A specific morphology was achieved by adding two SiO\u003csub\u003e2\u003c/sub\u003e and TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles to the membrane. The desired percent composition was selected based on the mass percent composition utilized in the experiments. In the material studio program, all of the structures were given to the Amorphous Cell module, and the membrane structure was built using the default density to get the required membrane structure. Figure \u003cspan class=\"InternalRef\"\u003e14\u003c/span\u003e shows a schematic representation of the achieved membrane.\u003c/p\u003e\n \u003cp\u003eIn the LAMMPS molecular dynamics simulator, the equilibrium and associated polymer consistent force field (pcff) coefficients were determined for each atom type [\u003cspan class=\"CitationRef\"\u003e29\u003c/span\u003e]. The cut-off radius for electrostatic was chosen as 12 A\u0026ordm;, and Van der Waals interaction was chosen as 12 A\u0026ordm;. The long-distance electrostatic interactions of the system were calculated using the k-space algorithm [\u003cspan class=\"CitationRef\"\u003e30\u003c/span\u003e]. The temperature and pressure of the system were controlled using a Nose-Hoover thermostat and barostat during the membrane preparation [\u003cspan class=\"CitationRef\"\u003e31\u003c/span\u003e]. Also, the Tdamp and Pdamp values were chosen as 100 and 1000, respectively. In all stages, the time step was set at 1 femtosecond.\u003c/p\u003e\n \u003cp\u003eOf designs established to compress and balance the membrane density, two cases are discussed as follows. In 2000, a 12-step preliminary compression design was introduced [\u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e], followed by the 12-step annealing and compression design [\u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e]. Later, in 2011, a general overview was developed based on the 12-step annealing and compression design [\u003cspan class=\"CitationRef\"\u003e33\u003c/span\u003e]. Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003epresents the characteristics of this 21-step compression/equilibrium general design utilized for density balance. This 21-step design is known as a simulated annealing algorithm where the membrane is periodically cooled and heated to generate the final structure. During compression, the box changes dimensions and overcomes the energy barriers on the study system. As a result, the final density of the system will have a more precise equilibrium value besides its more reliable morphology. \u0026nbsp;\u003c/p\u003e\n \u003ctable border=\"1\" id=\"Tab3\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eCompression design.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eStage\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSlow decentralization\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eTime (ps)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNVT 600 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e50\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNVT 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e50\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNPT 0.02Pmax bar, 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e50\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 and 5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNVT 600 K, NVT 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e50, 100\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNPT 0.6Pmax bar, 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e50\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7 and 8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNVT 600 K, NVT 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e50, 100\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNPT Pmax bar, 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e50\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10 and 11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNVT 600 K, NVT 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e50, 100\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNPT 0.5Pmax bar, 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e5\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13 and 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNVT 600 K, NVT 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e5, 10\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNPT 0.1Pmax bar, 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e5\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16 and 17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNVT 600 K, NVT 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e5, 10\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNPT 0.01Pmax bar, 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e5\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e19 and 20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNVT 600 K, NVT 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e5, 10\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNPT 1 bar, 300 K\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e100\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\"\u003eP max\u0026thinsp;=\u0026thinsp;40 Gpa\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003cp\u003eThe system is fed into NVT and NPT ensembles regularly in this design. At each ensemble, the compaction is carried out by increasing the temperature and pressure of the system. Then, periodic boundary conditions were applied to all three dimensions following the Mont Carlo GCMC simulations using LAMMPS molecular dynamics simulator. The nature of the interactions between the adsorbent and adsorbed molecules was determined using a force field similar to that utilized for the membrane. An in-house program was used to convert the Ceftriaxone molecule\u0026apos;s parameters into the files required for LAMMPS simulation. The adsorption coefficients were calculated at three temperatures of 21\u0026deg;C, 28\u0026deg;C, and 37\u0026deg;C and a radiation frequency of 12 A\u0026ordm; by applying the pressure ranging from 1 kPa to 10000 kPa. After balancing the system with 106 steps, additional 106 steps were completed to acquire and evaluate data.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec13\"\u003e\n \u003ch2\u003eAdsorption of cefotaxime molecules on membranes\u003c/h2\u003e\n \u003cp\u003eCefotaxime adsorption isotherms were determined on the membrane surface in the pressures ranging from 1kPa to 10000 kPa, at three different temperatures of 21\u0026deg;C, 28\u0026deg;C, and 37\u0026deg;C, as shown in Figs. \u003cspan class=\"InternalRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan class=\"InternalRef\"\u003e17\u003c/span\u003e.\u003c/p\u003e\n \u003cp\u003eIt was revealed that the adsorption rate of cefotaxime on the membrane at 21\u0026deg;C and 28\u0026deg;C is approximately 2.6 times the adsorption rate at 37\u0026deg;C at a pressure of 1 kPa. Figure \u003cspan class=\"InternalRef\"\u003e16\u003c/span\u003e. shows the adsorption rate of cefotaxime at a temperature of 21\u0026deg;C. As shown in the figure, at extreme pressure, the membrane adsorption is about 15 molecules per membrane (by adding the percentages from the previous section). At this temperature and pressures near 3000 kPa, the cefotaxime adsorption is constant, indicating that membrane sites are saturated at this pressure and temperature. Figure \u003cspan class=\"InternalRef\"\u003e17\u003c/span\u003e. shows the adsorption rate of cefotaxime at 28\u0026deg;C. The adsorption curve shows the adsorption rate of 16 cefotaxime molecules at zero pressures so that the adsorption rate should be increased by increasing pressure. Although the membrane seems to exhibit evidence of saturation at a pressure of 9000 kPa, this figure does not show the degree of saturation for this membrane versus cefotaxime at 28\u0026deg;C.\u003c/p\u003e\n \u003cp\u003eWhen comparing the adsorption diagrams at 21\u0026deg;C and 28\u0026deg;C, it can be found that a similar pattern can be anticipated for cefotaxime adsorption at two temperatures, implying that the adsorption rate of cefotaxime molecules at both temperatures is comparable. Figure \u003cspan class=\"InternalRef\"\u003e17\u003c/span\u003e. shows the adsorption rate of cefotaxime at 37\u0026deg;C. The adsorption diagram does not follow the same pattern as the previous two temperatures, which is surprising. At 37\u0026deg;C, the adsorption rate of the membrane is much lower than at the previous two temperatures at pressures near zero. At high pressures, a similar pattern can be seen, which means that the membrane follows a similar pattern and is saturated at much lower pressures.\u003c/p\u003e\n \u003cp\u003eFigure 18 shows the morphological analysis of the membrane after maximum cefotaxime is absorbed at the three desired temperatures, in addition to the density of adsorbed cefotaxime as aqua fields or phases in the membrane (distribution of cefotaxime molecules on the membrane). In addition, the occupied membrane sites are shown at all three temperatures, representing the membrane cavities available to trap the cefotaxime molecules.\u003c/p\u003e"},{"header":"Discussion And Conclusions","content":"\u003cp\u003eThe present study was conducted to modify the PES polymeric membrane using two nanoparticles for cefotaxime removal from the hospital wastewater. Based on the results from laboratory studies, the pH value, temperature, contact time, and initial concentration improve the effectiveness of the membrane. It can be concluded from diagrams that the maximum cefotaxime adsorption by this membrane containing nanoparticles was realized at the pH value of 5. The quantity of hydrogen ions and the antibiotic ions-adsorbent bond reduces by increasing the pH value. The drug-adsorption equilibrium time was 180 min, where 100% adsorption occurred. The initial concentration of cefotaxime was another important parameter affecting the adsorption kinetics and the effective and fast practical application of membranes. The results showed that the adsorption rate decreases by increasing drug concentration, which might be because of membrane fouling and adsorption sites\u0026apos; saturation. The results from the analysis of adsorption kinetics using a synthetic membrane indicated that the quasi first-order model could describe the kinetic behavior of adsorption due to higher computational value than the value obtained from laboratory data (q\u003csub\u003ee. exp\u003c/sub\u003e) and also the determined R\u003csup\u003e2\u003c/sup\u003e value using the quasi first-order model. The Langmuir isotherm model-based adsorption capacity calculations at temperatures of 21 and 37\u0026deg;C confirmed that 0\u0026thinsp;\u0026lt;\u0026thinsp;RL\u0026thinsp;\u0026lt;\u0026thinsp;1 of the adsorption means that the best adsorption of drug molecules using the adsorbent follows a linear pattern. The constants and parameters of the Freundlich isotherm model, as well as the value of n in cefotaxime adsorption in real hospital wastewater using the synthetic membrane containing nanoparticles, revealed that the cefotaxime adsorption in hospital wastewater was desirable and undesirable at 21\u0026deg;C and 37\u0026deg;C, respectively. The value achieved for R\u003csup\u003e2\u003c/sup\u003e using the Freundlich isotherm model for cefotaxime adsorption from hospital wastewater reflected the significant capability of this model in describing the adsorption isothermal of the drug. Examining the simulation diagrams with the LAMMPS molecular dynamics simulator confirmed the laboratory data and offered further data regarding the membrane morphology shown in the figures and diagram.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eFunding: Not applicable\u003c/p\u003e\n\u003cp\u003eConflicts of interest/Competing interests: Not applicable\u003c/p\u003e\n\u003cp\u003eAvailability of data and material (data transparency): All data and calculations can be presented and read if needed.\u003c/p\u003e\n\u003cp\u003eCode availability (software application or custom code): Since open-source software was utilized in this study, the data about it is also available to academics.\u003c/p\u003e\n\u003cp\u003eAuthors\u0026apos; contributions\u003cstrong\u003e:\u0026nbsp;\u003c/strong\u003eStudy concept and design: Zeinab Nikfarjam, Mohammad Momen Heravi, Mohammad Reza Bozorgmehr \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAcquisition of data and Analysis and interpretation of data: Mohammad Momen Heravi, Zeinab Nikfarjam (Experiments), Zeinab Nikfarjam, Mohammad Reza Bozorgmehr (Computational)\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDrafting of the manuscript\u003cspan dir=\"RTL\"\u003e:\u003c/span\u003e Zeinab Nikfarjam, Mohammad Momen Heravi, Mohammad Reza Bozorgmehr \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eStudy supervision: Mohammad Momen Heravi, Mohammad Reza Bozorgmehr \u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003ePoynton HC, Robinson WE (2018) Contaminants of emerging concern, with an emphasis on nanomaterials and pharmaceuticals. 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Macromolecules 44(17):6944\u0026ndash;6951\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 is available in the Supplemental Files section.\u003c/p\u003e\n"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Antibiotic removal, Membrane, Cefotaxime, Molecular dynamic simulations","lastPublishedDoi":"10.21203/rs.3.rs-1494699/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1494699/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAntibiotics may be regarded as novel and harmful contaminants in the ecosystem because of their increased usage worldwide and presence in wastewater, endangering people's health and the environment even in small amounts. Among the adverse effects of the compounds are drug resistance and alteration in biological cycles. The present study aims to remove one of the cephalosporin antibiotics (cefotaxime) from hospital wastewater using synthetic modified membranes containing nanoparticles based on the in vitro and molecular dynamics (MD) simulation study. To do so, first, Polyethersulfone (PES) polymeric membrane, silicon dioxide (SiO\u003csub\u003e2\u003c/sub\u003e), and titanium dioxide (TiO\u003csub\u003e2\u003c/sub\u003e) nanoparticles were synthetic in the practical phase. Then, the impact of different factors, including pH, concentration, and contact time, was examined on the efficiency of wastewater treatment. Thermodynamic studies were also conducted to identify and analyze the adsorption isotherms of the PES polymeric membrane. The results indicate that the PES polymeric membrane achieved the maximum surface adsorption at 37 \u0026deg; C, 180 min contact time, and pH\u0026thinsp;=\u0026thinsp;5. The simulations were performed using Materials Studio and LAMMPS molecular dynamics simulator. The efficiency of simulations was assessed when the boundary conditions and force field were determined. At various temperatures, the best operating temperature, adsorption isotherms, and membrane morphology have all been studied. The adsorption isotherms were determined on the membrane surface in a low-pressure range from 1 kPa to 10000 kPa and at three different temperatures 21\u0026deg;C, 28\u0026deg;C, and 37\u0026deg;C. According to the results, the adsorption rate of cefotaxime on the membrane at 21\u0026deg;C and 28\u0026deg;C is approximately 2.6 times the adsorption rate at 37\u0026deg;C and a pressure of 1 kPa. The distribution of molecules at the given temperatures, the position of the occupied membrane, and the membrane cavities for trapping cefotaxime molecules were all observed in the analysis of the density of cefotaxime adsorbed on the membrane surface. Finally, a good agreement was achieved between the simulation and experimental results for wastewater treatment.\u003c/p\u003e","manuscriptTitle":"Removal of Cefotaxime Antibiotics from Hospital Wastewater using TiO2 and SiO2 Nanoparticles-Modified Polyethersulfone Membrane: Experimental and Computational Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-04-05 19:41:31","doi":"10.21203/rs.3.rs-1494699/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"2a589e57-a154-4b87-bfcb-4bf52829c74c","owner":[],"postedDate":"April 5th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2022-04-05T19:41:33+00:00","versionOfRecord":[],"versionCreatedAt":"2022-04-05 19:41:31","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1494699","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1494699","identity":"rs-1494699","version":["v1"]},"buildId":"cBFmMYwuxLRRLfASyISRj","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}