Chemical and structural properties of Jordanian zeolitic tuffs and their admixtures with urea and thiourea: Potential scavengers for phenolics in aqueous medium

Native Jordanian zeolitic tuffs, rich in phillipsite, were treated with ure a and thiourea. The chemical and structural properties of the tuffs and the ir urea and thiourea admixtures were studied using SEM, XRF, XRD, and FTIR techniques, and their adsorption capacities were estimated by the methylene blue method, The urea and thiourea treatment has not affected the mineral constitution of the tuffs. The results revealed that urea and thiourea were linked by hydrogen bonding through the NH, moiety to the zeolite substrate , with urea showing the strongest effect. Experiments were carried out to i nvestigate the possible use of the prepared materials for the removal of ph enol and chlorinated phenols from aqueous solutions. Although thiourea caus ed a reduction in the relative surface area, both urea and thiourea admixtu res mere more effective than the free zeolitic tuff in the removal of pheno l and chlorinated phenols from water, with urea admixture displaying the la rgest removal capacity. (C) 1999 Academic Press.