活化剩余污泥对Pb^(2+)的吸附热力学研究  

On the thermodynamics of lead adsorption for the activating sewage sludge

作　　者：汪爱河[1] 张伟 鄢恒珍[1] 张纯[1] 

机构地区：[1]湖南城市学院市政与测绘工程学院,湖南益阳413000

出　　处：《安全与环境学报》2015年第4期191-196,共6页Journal of Safety and Environment

基　　金：湖南省教育厅优秀青年项目(13B009);湖南省高校产学研合作示范基地项目(湘教通[2014]239号)

摘　　要：以城市污水处理厂脱水干污泥为原料,以浓硫酸为活化剂,制备活化剩余污泥吸附剂,采用正交试验法考察了Pb2+初始质量浓度、初始p H值、吸附温度、活化剩余污泥投加量对活化剩余污泥吸附性能的影响。结果表明,活化剩余污泥对Pb2+的最佳吸附条件为Pb2+初始质量浓度60 mg/L、初始p H值5、活化剩余污泥投加量100mg、吸附温度288 K,影响从高到低的各因素为Pb2+初始质量浓度、吸附温度、初始p H值、活化剩余污泥投加量。采用Langmuir、Freundlich、D-K-R吸附等温方程对不同温度下的吸附平衡试验数据进行拟合。Langmuir吸附等温方程可以较好地描述活化剩余污泥对Pb2+的吸附平衡过程。其吸附过程吉布斯自由能ΔG为-3.35^-0.32 k J/mol,焓变ΔH和熵变ΔS均为负值,表明活化剩余污泥对Pb2+的吸附是自发的、以物理吸附为主的放热反应。The present article is aimed at a study of the sewage adsorption feature for the activating sewage sludge by using the activated sludge with sulphuric acid absorpting function. For the said demand,we have first of all made an exploration of the factors that may affect the adsorptive process,such as the initial Pb2 ＋mass concentration,the adsorption temperature,the initial p H and the dosage of the activation sewage sludge by using the orthogonal experiment（ L16（ 45））. Secondly,we have worked out the kinetic data by means of the pseudo first-order equation and the pseudo second-order equation. And,thirdly,we have analyzed the equilibrium isotherms by using the Langmuir,the Freundlich and the D-K-R isotherms. Fourthly,and calculated the free energy changes ΔG,the enthalpy changes of ΔH and that ofΔS with the thermodynamic equation. And,finally,we have worked out the morphology of the samples we have chosen,which can be gained by scanning electronic microscope techniques（ SEM） with the adsorption mechanism being discussed. The results of our calculation and investigation have shown that the best adsorption conditions should be kept on the initial Pb2 ＋mass concentration of 60 mg / L,the initial p H value of 5,the adsorption temperature of 288 K,dosage of activation sewage sludge of 100 mg. After all,the initial Pb2 ＋mass concentration has been found having the greatest effect on the adsorption,which is followed by the adsorption temperature,the initial p H and the dosage of activated sewage sludge. Besides,it is also be possible to describe the adsorption process by the pseudo second-order equation.What is more,the equilibrium data should be made well fitted by Langmuir isotherm so as to make the maximum adsorption capacity of the activated sewage sludge reach 27. 83 mg / g,27. 86 mg /g,26. 41 mg / g,20. 78 mg / g at 288 K,298 K,308 K,318 K,respectively. Thus,it can be found that the adsorption capacity may tend to decrease with the rising adsorption temperature,which implies that the rising tem

关 键 词：环境工程学 吸附等温线 吸附热力学 活化剩余污泥 铅 

分 类 号：X703.1[环境科学与工程—环境工程]