As(III) Adsorption from Drinking Water on Nanoscale Zero-Valent Iron: Kinetics and Isotherm Studies

摘要

Nanoscale zero-valent iron (NZVI) is increasingly gaining interest as an efficient sorbent for various types of aqueous pollutants. This paper examined the potential for using laboratory synthesized NZVI particles (~40 nm, 49.2 m~2/g) to remove arsenite [As(III)] from drinking water. Batch experiments were conducted to study the removal kinetics, sorption isotherms, and the effect of anions or heavy metal ions on arsenic removal with NZVI. NZVI demonstrated very rapid adsorption and large capacity for the removal of As(III). The maximum As(III) adsorption capacity in batch experiments calculated by Langmuir adsorption isotherm was 76.3 mg/L of As(III)/g of NZVI. The reduction of As(III) followed a pseudo-first-order kinetics that the rate constants (k_(SA)) was 3.42 mUm~2 min. This study suggests that implementation of NZVI for remediation of As(III) from drinking water is sufficient.