PDA-assisted immobilization of nZVI on cotton fabric for the removal of Rhodamine B and Chromium (VI) ion

Abstract Printing and dyeing wastewater can cause serious environmental pollutant and must be treated to meet the emission standards before discharge. In this study, we report a method to prepare nano zero-valent iron (nZVI) particle-immobilized cotton (nZVI@cotton) fabrics assisted by polydopamine (PDA) deposition using cotton fabrics as the substrate. The nZVI@cotton fabric was systematically characterized using SEM, EDS, FTIR and TEM. The mechanical property tests of cotton fabric revealed a significant improvement in the breaking strength after deposition of PDA. The pollutant removal capability of nZVI@cotton fabric was evaluated using rhodamine B and Cr(VI) as models. The decolorization efficiency of rhodamine B could be up to 79.45% and Cr(VI) removal efficiency was 70.74% within 60 min, respectively. In addition, the iron content, different nZVI@cotton fabric system, the effect of pollutant composition and reusability of nZVI@cotton fabric were systematically investigated. Results showed that nZVI@cotton fabric prepared with the assistance of PDA was a kind of comparable wastewater purification material with the advantages of high removal efficiency to rhodamine B and Cr(VI) ions and easy to be recycled.