Remediation of arsenic(III) from aqueous solutions using zero-valent iron (ZVI) combined with potassium permanganate and ferrous ions

Abstract

A system of zerovalent iron combined with potassium permanganate and ferrous irons (Fe(II)-KMnO4-ZVI)was used to remove As(III), one of themost poisonouswastewater pollutants. The Fe(II)- KMnO4-ZVI system was characterized by using X-ray photoelectron spectroscopy and scanning electron microscopy. The As(III) removal efficiency by the Fe(II)-KMnO4-ZVI system under different conditions was investigated and the experimental datawere fitted to adsorption kinetics and isothermmodels. As(III) could be removed by both physisorption and chemisorption through mixing adsorbents in a very short time (minute scale) with high removal ratios (more than 99.5%) over a wide range of pH (1-9) and concentration (20-100 mg/L). The removal of As(III) by the Fe(II)-KMnO4-ZVI system agreed well with pseudo-first-order reaction kinetics and pseudo-second-order reaction kinetics. The Freundlich isotherm provided a good model of the adsorption system, indicating that the Fe(II)-KMnO4-ZVI system has heterogeneous structure. The results show that the Fe(II)-KMnO4-ZVI system exhibited a high removal efficiency for As(III), which suggested that it might be an effective material for As(III) remediation.