A continuous method for arsenic removal from groundwater using hybrid biopolymer-iron-nanoaggregates: improvement through factorial designs

Abstract

BACKGROUND: Due to a variety of toxicological problems, the presence of As(V) in aquifers is a significant concern. Sorption using chitosan doped with iron nanoaggregates results in a green and cheap methodology for its elimination. RESULTS: The hybrid sorbent was characterized by SEM, EDS, TGA, XRD, and FTIR spectroscopy. Its stability against pH and time was determined by ICP-MS, while conventional analytical techniques verified its Fe content. The sum of an individual As(V) removal capacity by chitosan and iron nanoaggregates was smaller than that of the hybrid sorbent, indicating the existence of synergy. CONCLUSION: This study demonstrates the great capacity of the hybrid sorbent to eliminate As(V) working with a continuous system (columns). The additional use of a factorial design allows for determining of optimal operating values to optimize two responses. In other words, in this multi-response system, column service time (tb) was minimized and, at the same time, it maximized the volumes of purified water obtained ([As(V)] <0.05 m L−1) using desirability function.