Present invention deals with cost-effective surface-modified zeolite
materials developed from commercial zeolites and flyash-based zeolites by
treating with surface modifiers like hexadecyltrimethyl ammonium bromide
(HDTMA-Br). The formation of zeolitic materials with anionic
characteristics requires treatment with a surfactant with initial
concentrations greater than its critical micelle concentration (CMC). The
sorption of oxyanions on the surfactant-modified zeolite (SMZ) is
attributed to surface complexation and surface precipitation.
Incorporation of metal ions on SMZ showed improved anion uptake for
dearsenification of water due to synergistic effects and is able to meet
the stringent target of 10 ppb of As on potable water being adopted by
most countries. High selectivity, faster kinetics and high adsorption
capacity ensures cost effectiveness of this product as compared to other
low-cost products for dearsenification. Zeolite analogues with anionic
characteristics have been developed for their applications for removal of
arsenic from water. The material developed can also be used to remove
other anions like chromium and selenium.