Sorption removal of cephalexin by HNO_3 and H_2O_2 oxidized activated carbons  

作　　者：LIU WeiFeng XIE HuiJun ZHANG Jian ZHANG ChengLu 

机构地区：[1]Shandong Key Laboratory of Water Pollution Control and Resource Reuse,School of Environmental Science and Engineering,Shandong University,Jinan 250100,China [2]Environment Research Institute,Shandong University,Jinan 250100,China

出　　处：《Science China Chemistry》2012年第9期1959-1967,共9页中国科学（化学英文版）

基　　金：supported by the National Key Technology R&D Program for the 11th Five-year Plan (2006BAC10B03);the National Water Special Project (2009ZX07210-009-04);the Scientific Technology Research and Development Program of Shandong,China (2010GZX20605);Graduate Independent Innovation Foundation of Shandong University(2009JQ009)

摘　　要：Cephalexin＇s traces within pharmaceutical effluents have toxic impact toward ecological and human health. Low-cost activated carbon derived from Trapa natans husk was oxidized with hydrogen peroxide and nitric acid, and tested for their ability to re- move cephalexin from aqueous solutions. Oxidization with H202 showed negative effect on the cephalexin sorption, whereas HNO3 oxidization improved the adsorption. The cephalexin adsorption isotherms on the native and HNO3 oxidized carbons correlated well with the Freundlich equation while their kinetics followed the pseudo-second order model. The removal of cephalexin by the native and HNO3 oxidized carbons was found to be most favored at low ionic strength and strong acidic conditions. Based on the thermal and FTIR analyses, the interaction mechanisms of the interaction between cephalexin and the carbons were proposed. Electrostatic attraction, hydrophobic interaction and chemical bonding with surface functional groups were demonstrated as primary mechanisms for cephalexin removal. The nitrogen functionalities on the carbon surface were considered to be an important factor affecting the adsorption process.Cephalexin's traces within pharmaceutical effluents have toxic impact toward ecological and human health.Low-cost activated carbon derived from Trapa natans husk was oxidized with hydrogen peroxide and nitric acid,and tested for their ability to remove cephalexin from aqueous solutions.Oxidization with H2O2 showed negative effect on the cephalexin sorption,whereas HNO3 oxidization improved the adsorption.The cephalexin adsorption isotherms on the native and HNO3 oxidized carbons correlated well with the Freundlich equation while their kinetics followed the pseudo-second order model.The removal of cephalexin by the native and HNO3 oxidized carbons was found to be most favored at low ionic strength and strong acidic conditions.Based on the thermal and FTIR analyses,the interaction mechanisms of the interaction between cephalexin and the carbons were proposed.Electrostatic attraction,hydrophobic interaction and chemical bonding with surface functional groups were demonstrated as primary mechanisms for cephalexin removal.The nitrogen functionalities on the carbon surface were considered to be an important factor affecting the adsorption process.

关 键 词：CEPHALEXIN activated carbon OXIDATION ADSORPTION mechanism 

分 类 号：TQ324.4[化学工程—合成树脂塑料工业] TQ465.1