Heavy metal adsorption by a formulated zeolite-Portland cement mixture.
Large amounts of fine zeolite by-product were produced when natural zeolite was processed into a powder with a specific particle size. In Korea, large piles of this by-product exist with no disposal options. We conducted studies to determine whether mixtures of this by-product with other materials could be used as a substitute to activated carbon for wastewater treatment. A granular material was formulated by mixing zeolite by-product with Portland cement (ZeoAds), and this material was tested for its efficiency for heavy metal removal from aqueous solutions. The ZeoAds removed Pb and Cu in an aqueous solution up to 27.03 and 23.25 mg g(-1), respectively. Adsorption kinetics of the ZeoAds for heavy metals was first-order, and the ZeoAds removed about 90% of the Cu within 30 min. At solution pH lower than five, the adsorption specificity of the ZeoAds for metals was Pb>Cu>Cd>or=Zn. Langmuir isotherms adequately described the adsorption, and adsorption capacity increased as the particle size decreased to 2 mm in diameter. The maximum adsorption capacities of the metals for the ZeoAds were, irrespective of the kinds of metals, about two times greater than those of activated carbon. Column experiments demonstrated that the ZeoAds was more efficient and had a higher sorptive capacity than activated carbon for removing metals from industrial wastewater.
Ok
Yong Sik
YS
Department of Renewable Resources, University of Alberta, Edmonton, Alberta T6G 2E3, Canada.
Yang
Jae E
JE
Zhang
Yong-Seon
YS
Kim
Su-Jung
SJ
Chung
Doug-Young
DY
D000327:Adsorption; D003252:Construction Materials; D007220:Industrial Waste; D019216:Metals, Heavy / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods; D017641:Zeolites
D007220:Industrial Waste; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D017641:Zeolites