Adsorptive Removal of Fluoride from Water by Heat-Treatment Waterworks Alum Sludge  

作　　者：帖靖玺 米晓 张西旺 

机构地区：[1]School of Environmental and Municipal Engineering,North China University of Water Resources and Electric Power [2]Department of Chemical Engineering,Faculty of Engineering,Monash University

出　　处：《Journal of Donghua University(English Edition)》2014年第1期18-24,共7页东华大学学报（英文版）

基　　金：Research Fund for Introduced High-Level Talents of North China University of Water Resources and Electric Power,China;Research Fund for Key Scientific Project of Education Department of Henan Province,China(No.13B560114);Joint Research Fund for Overseas Chinese Scholars and Scholars in Hong Kong and Macao,China(No.51328803)

摘　　要：Alum sludge （AS） is a world-wide by-product generated in the drinking water treatment process when aluminum salts are used as coagulant. Its high AI content makes it a potential adsorbent for flouride removal from water. A high performance adsorbent was fabricated via heat treatment of AS and batch adsorption experiments were carried out to investigate its flouride adosroption performance. The results indicated that AS treated at 300℃ （AS300） for 1 h had the highest adsorption capacity for fluoride （52.9% fluoride removal）. The adsorption of fluoride by AS300 fitted better the Langmuir isotherm model than the Freundlich model. The maximum fluoride adsorption capacity of AS300 increased from 4.0 to 9.3 mg/g sludge when reaction temperature increased from 15 to 35 ℃. Thermodynamic parameters showed that the adsorption of fluoride by AS was spontaneous and endothermie. Hence higher temperature was favorable for fluoride adsorption. The adsorption process followed the pseudo-second-order equation. In addition, the fluoride adsorption on AS300 decreased from 4.3 to 2.5 mg/g sludge when the solution initial pH increased from 4.0 to 9.0, which meant that adsorption capacity was greatly dependent upon the initial pH of the solution. The results provide new insight into the resource utilization of AS for fluoride removal.Alum sludge( AS) is a world-wide by-product generated in the drinking water treatment process when aluminum salts are used as coagulant. Its high Al content makes it a potential adsorbent for flouride removal from water. A high performance adsorbent was fabricated via heat treatment of AS and batch adsorption experiments were carried out to investigate its flouride adosroption performance. The results indicated that AS treated at 300℃( AS300) for 1 h had the highest adsorption capacity for fluoride( 52. 9% fluoride removal). The adsorption of fluoride by AS300fitted better the Langmuir isotherm model than the Freundlich model. The maximum fluoride adsorption capacity of AS300increased from 4. 0 to 9. 3 mg /g sludge when reaction temperature increased from 15 to 35 ℃. Thermodynamic parameters showed that the adsorption of fluoride by AS was spontaneous and endothermic.Hence higher temperature was favorable for fluoride adsorption.The adsorption process followed the pseudo-second-order equation.In addition,the fluoride adsorption on AS300 decreased from 4. 3 to2. 5 mg /g sludge when the solution initial pH increased from 4. 0 to9. 0,which meant that adsorption capacity was greatly dependent upon the initial pH of the solution. The results provide new insight into the resource utilization of AS for fluoride removal.

关 键 词：alum sludge （AS） FLUORIDE adsorption isotherm kinetic modelinf THERMODYNAMICS 

分 类 号：X703.5[环境科学与工程—环境工程]