Removal of As(III) and As(V) from water using reduced GO-Fe0 filled PANI composite

Abstract

A novel ternary adsorbent was prepared by reductive deposition of zerovalent iron on reduced graphene oxide through in-situ polymerization of aniline. SEM/EDS study showed an irregular, porous, and heterogeneous surface morphology with iron available for As binding. Batch adsorption experiments were conducted to determine the optimum conditions for As adsorption with optimum adsorbent dose, initial concentration of As, pH etc. Under optimized conditions, the maximum removal percentage of As was 99.6% for As(III) and 89% for As(V). The adsorption of arsenic on the composite was fitted well to the pseudo-second-order kinetic model and obeyed both Langmuir [R 2 = 0.955 for As(III) and 0.992 for As(V)] and Freundlich [R 2 = 0.975 for As(III) and 0.993 for As(V)] models. In aqueous solutions, the common co-ions phosphate hindered As removal more than the any other ions. The absorptive ability of adsorbent was compared with those of different adsorbents and found to be considerably efficient.