Kinetics and equilibrium of adsorption of dissolved organic matter fractions from secondary effluent by fly ash  

作　　者：Liangliang Wei Kun Wang Qingliang Zhao Chunmei Xie Wei Qiu Ting Jia 

机构地区：[1]School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China [2]State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China

出　　处：《Journal of Environmental Sciences》2011年第7期1057-1065,共9页环境科学学报（英文版）

基　　金：supported by the National Nature Science Foundation of China (National Creative Research Groups)(No. 50821002);the Key Scientific and Technological Project of National Water Pollution Control and Management (No. 2009ZX07317-008);the Scientific and Technological Innovation Research Fund of Harbin (No.2010RFQXN111)

摘　　要：Fly ash was used as a low-cost adsorbent for removing dissolved organic matter （DOM） in secondary effluent. Batch experiments were conducted under various adsorbent dosages, pH, contact time, temperatures and DOM fractional characteristics. Under the optimum conditions of fly ash dosage of 15 g/L, temperature of 303 K and contact time of 180 min, a removal of 22.5% of the dissolved organic carbon （DOC）, 23.7% of UV-254, 25.9% of the trihalomethanes precursors in secondary effluent was obtained. The adsorption of DOM fractions onto fly ash all followed the pseudo second-order kinetic model, and the hydrophilic fraction adsorption by fly ash also fitted the intraparticle diffusion model quite well. Freundlich and Langmuir models were applicable to the fly ash adsorption and their constants were evaluated. The maximum adsorption capacities of the adsorptions revealed that fly ash was more effective in adsorbing hydrophilic fraction than the acidic fractions. Structure changes of the DOM fractions after fly ash adsorption were also characterized via spectrum analyzing. Those mechanisms presented critical step toward improved efficiencies of fly ash adsorption via further surface-modification.Fly ash was used as a low-cost adsorbent for removing dissolved organic matter （DOM） in secondary effluent. Batch experiments were conducted under various adsorbent dosages, pH, contact time, temperatures and DOM fractional characteristics. Under the optimum conditions of fly ash dosage of 15 g/L, temperature of 303 K and contact time of 180 min, a removal of 22.5% of the dissolved organic carbon （DOC）, 23.7% of UV-254, 25.9% of the trihalomethanes precursors in secondary effluent was obtained. The adsorption of DOM fractions onto fly ash all followed the pseudo second-order kinetic model, and the hydrophilic fraction adsorption by fly ash also fitted the intraparticle diffusion model quite well. Freundlich and Langmuir models were applicable to the fly ash adsorption and their constants were evaluated. The maximum adsorption capacities of the adsorptions revealed that fly ash was more effective in adsorbing hydrophilic fraction than the acidic fractions. Structure changes of the DOM fractions after fly ash adsorption were also characterized via spectrum analyzing. Those mechanisms presented critical step toward improved efficiencies of fly ash adsorption via further surface-modification.

关 键 词：fly ash ADSORPTION dissolved organic matter FRACTIONATION KINETICS 

分 类 号：X76[环境科学与工程—环境工程] S153[农业科学—土壤学]