title: Preparation and Characterization of Ceramic Hollow Microspheres for Heavy Metal Ion Removal in Wastewater.
abstract: Ceramic hollow microspheres (CHMSs) were prepared to use as supports for the removal of heavy metal ions from industrial waste-water. A water extraction sol-gel technique was used to prepare porous CHMS by extracting water from an emulsion of LUDOX (silica colloid; SiO(2), Aldrich Co.) and 2-ethyl-1-hexanol. Experiments were conducted to control pore size, wall thickness, and separation yield by examining the ratio of precursors (LUDOX and 2-ethyl-1-hexanol), catalyst (NH(4)OH), sintering temperature, surfactant (SPAN 80), extractant (n-butanol), stirring speed, and concentration of precursor (LUDOX). The results revealed that the optimum conditions were 20 ml of a 10 wt% solution of LUDOX, 10 ml of NH(4)OH, a sintering temperature of 500 degrees C, 0.4 ml of SPAN 80, 200 ml of n-butanol, and a stirring speed of 730 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 solution. 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)). Copyright 2000 Academic Press.
authors.affiliation: School of Chemical Engineering, Seoul National University, San 56-1 Shinlim-dong, Kwanak-gu, Seoul, 151-742, Korea
authors.initials: E
authors.lastname: Bae
authors.initials: S
authors.lastname: Chah
authors.initials: J
authors.lastname: Yi