Polyurea Membrane as potential purifying technology for Water Cleaning: Kinetic and Equilibrium Modeling of Dyes Adsorption

Abstract A treatment of water from aqueous solutions was reported in this work using polyurea (PU) as a novel adsorbent. Dyes with different characteristics (Congo red (CR) and methylene blue (MB)) were examined for their adsorption on polyurea. The PU membrane was achieved by a reaction between a polyetheramine and polyisocyanate using sol-gel chemistry. FTIR results confirmed the formation of urea groups, and the polymeric membrane showed high homogeneity, making it a viable purifying technology for wastewater. The high swelling capacity of the membrane showed an important role in CR dye diffusion/adsorption. PU membranes exhibited excellent adsorption to CR anionic dye, with a removal efficiency of more than 85%. However, MB dye adsorption was not favorable, suggesting a high affinity with anionic species. Adsorption of CR dye onto PU followed the pseudo-second order kinetic and Langmuir isotherm models. The intraparticle diffusion model demonstrated that the swelling of PU facilitated the asorption/diffusion process and accelerated the mass transfer of the CR dye onto the membrane. Our findings suggest that PU membranes derived from commercially available reagents are promising for the decontamination of dye wastewater.