Preparation and Characterization of Ceramic Hollow Microspheres for Heavy Metal Ion Removal in Wastewater

摘要

Ceramic hollow microspheres (CHMSs) were prepared to use as sipports for the removal of heavy metal ions from industrial waste-water. A water extraction sol—gel technique was used to prepare ~rous CHMS by extracting water from an emulsion of LUDOX (silica colloid; 5K)2, Aldrich Co.) and 2-ethyl-1-hexanol. Experi-ments were conducted to control pore sire, wall thickness, and sep-aration yield by examining the ratio of precursors (LUDOX and 2-ethyl-1-hexanol}, catalyst (NH4OH), sintering temperature, sur-factant (SPAN 80), extractant (n-butaool), stirring speed, and con-centration of precursor (LUDOX). The results revealed that the optimum conditions were 20 ml of a 10 wt% sQiution of LUDOX, 10 ml of NH4OH, a sititering temperature of 30OOC~ d.4 ml of SPAN ~, 200 ml of n-butanol, and a stirring speed of 73t) rpm/100 ml of 2-ethyl.1-hexanol. CHMSs were impregnated in Cyanex 272 and examined for their ability to remove heavy metal ions from a solu-tion. Based on an experiment involving the removal of metal ions using CHMSs that were prepared under optimum conditions, Zn Ion was removed at a level of 0.354 mmol/g at pH 4, which was about twice the adsorption capacity of CHMSs prepared by Wilcox (Mater. Res. Soc. Symp. Proc. 346,201 (1994)).