不同热解温度污泥生物炭对Pb^(2+)、Cd^(2+)的吸附特性  

Adsorption characteristic of Pb^(2+)and Cd^(2+)with sludge biochars derived at different pyrolysis temperatures

作　　者：郑凯琪 王俊超[1] 刘姝彤[1] 薛红波[1] 吴继阳[1] 刘天宇[1] 尹微琴[1] 王小治[1,2] 

机构地区：[1]扬州大学环境科学与工程学院,扬州225127 [2]江苏省有机固体废弃物资源化协同创新中心,南京210095

出　　处：《环境工程学报》2016年第12期7277-7282,共6页Chinese Journal of Environmental Engineering

基　　金：江苏省社会发展项目(BE2014680;BE2015661);江苏省六大人才高峰项目(NY-017);江苏省企业研究生工作站项目资助

摘　　要：采用剩余污泥为原料,分别于300、400、500℃缺氧条件下制备污泥生物炭,利用X射线能谱仪(EDS)、环境扫描电镜(SEM)、红外光谱(FTIR)对其进行表征,并探究不同吸附时间,不同pH和不同Pb^(2+)、Cd^(2+)浓度下污泥生物炭对Pb^(2+)、Cd^(2+)的吸附特性,以期拓展污泥资源化利用途径。结果表明,准二级动力学方程能更好地描述污泥生物炭对Pb^(2+)、Cd^(2+)的吸附过程,约30 h达到平衡,其吸附主要受化学吸附控制。随溶液初始pH的升高,重金属的吸附量呈先增高后降低趋势,在pH 4.5时对Pb^(2+)的吸附量最大,而Cd^(2+)在pH 6.5时最大。在25℃时,低温热解制备的污泥生物炭对Pb^(2+)、Cd^(2+)的吸附量为RC500>RC400>RC300,RC500的饱和吸附量分别为Pb^(2+)(14.39 mg·g^(-1))>Cd^(2+)(1.45 mg·g^(-1)),污泥生物炭对重金属离子的吸附量与其水合离子半径呈负相关。To achieve sludge resource utilization,sludge-derived biochars were prepared at different pyrolysis temperatures（ 300,400,500 ℃） using surplus sludge as raw materials. The biochars were characterized using EDS,SEM,and FTIR,and the adsorption of Pb^（2＋）and Cd^（2＋）by sludge-derived biochars was investigated at different sorption times,solution pH values,and Pb^（2＋）and Cd^（2＋）concentrations. The results showed that a pseudo-second-order kinetic model can effectively describe the adsorption of Pb^（2＋）and Cd^（2＋）by sludge-derived biochars over a period of about 30 h,which was mainly controlled by chemical reaction. As the solution pH values increased,the amount of Pb^（2＋）and Cd^（2＋）absorbed by the sludge-derived biochars gradually increased and then decreased. The adsorption amount of Pb^（2＋）maximized at pH 4. 5,while that of Cd^（2＋）maximized at pH 6. 5. The amount of Pb^（2＋）and Cd^（2＋）absorbed by sludge-derived biochars was in the order RC500 RC400 RC300 at 25℃,and the Pb^（2＋）adsorption capacity of RC500 was 14. 39 mg · g^-1more than its Cd^（2＋）adsorption capacity（ 1. 45 mg·g^-1）. It indicated that the amount of heavy metals adsorbed by sludge-derived biochars was inversely proportional to hydrated ionic radius of the heavy metals.

关 键 词：污泥生物炭 吸附 铅 镉 

分 类 号：X703[环境科学与工程—环境工程]