Biosynthesis based membrane filtration coupled with iron nanoparticles reduction process in removal of dyes

In this work, filtration of membrane and reduction of iron nanoparticles (FeNPs) was coupled to remove dyes with different molecular weight. The FeNPs–Calcium alginate (CaAlg) composite membrane was biosynthesized using green tea. The FeNPs–CaAlg composite membrane was characterized by series of instruments. The results indicate that the FeNPs-CaAlg membrane has an excellent performance in filtrating dyes, nearly the same filtration flux with purified water and almost no flux reduction with filtration time. The FeNPs-CaAlg membrane exhibits different rejection performance for dyes with different molecular weight. The mechanism was discussed and it can be concluded that, for dyes with small molecular weight like crystal violet, besides the influence of the change in the effective channel size made by the load of FeNPs, the intensive reducibility of FeNPs also has great effect on the rejection rate.