Zeolite Performance as an Anion Exchanger for Arsenic Sequestration in Water

摘要

Zeolites are well known for their use in ion exchange and acid catalysis reactions. The use of zeolites in anion or ligand exchange reactions is less studied. The NH_4~+ form of zeolite Y (NY6, Faujasite) has been tested in this work to evaluate its performance for arsenic removal from water in continuous-flow reactions. Zeolite NY6 performed well for arsenate removal under simple and complex inlet chemistries. The results from column studies indicate that contact time and zeolite particle size can be varied to optimize both the physical and chemical performance of the continuous-flow process. Evaluation of a physical mixture of NY6 and the NH_4~+ form of zeolite ZSM-5 indicate the potential for treatment of complex contaminant streams containing As, Cd, Pb and MTBE. Overall, these experimental results indicate that synthetic zeolites offer significant flexibility in designing continuous-flow treatment processes for the removal of inorganic and organic contaminants in aqueous waste streams.