干硝化好氧颗粒污泥对Pb2+的吸附特性与机理  

Dried Biomass from Nitrified Aerobic Granular Sludge for Pb2+ Adsorption:Behaviors and Mechanisms

作　　者：刘名[1] 唐朝春[1] 衷诚[1] 陈惠民[1] 叶鑫[1] 

机构地区：[1]华东交通大学土木建筑学院

出　　处：《环境科学研究》2015年第12期1923-1930,共8页Research of Environmental Sciences

基　　金：江西省科学技术厅支撑计划项目(2009AE01601);江西省自然科学基金项目(20132BAB203033)

摘　　要：硝化好氧颗粒污泥具有孔隙率高、比表面积大、沉淀性能好等特征,为考察其在重金属废水处理中的应用效果,以干硝化好氧颗粒污泥为吸附剂,研究其对水溶液中Pb^2＋的吸附特性及影响因素.结果表明,Langmuir等温吸附方程可以很好地拟合干硝化好氧颗粒污泥对Pb^2＋的吸附过程,说明Pb^2＋在干硝化好氧颗粒上的吸附属于单分子层吸附,25℃下的饱和吸附容量为79.58 mg/g,R2为0.990 1.吸附动力学分析结果表明,该动态吸附平衡过程遵循伪二级动力学方程,废水初始ρ（Pb^2＋）分别为20、40、60 mg/L时,R2分别为1.000 0、1.000 0、0.999 9,同时颗粒内扩散方程RC（关联系数,分别为30.706%、28.019%、24.188%）均低于50%,表明颗粒内扩散是控制Pb^2＋吸附速率的关键步骤.红外扫描分析（FTIR）结果表明,吸附过程中Pb^2＋主要与干硝化好氧颗粒污泥表面的O—H、N—H、CO、CC、C—OH、C—O—C等基团发生了作用.吸附前、后的pHZCP（零点电荷）由2.5升至3.1,说明Pb^2＋在干硝化好氧颗粒污泥上的吸附属于专性吸附,即发生了紧密层吸附.研究显示,干硝化好氧颗粒污泥对Pb^2＋具有较好的吸附效果,吸附机制主要包括无机微沉淀、表面络合、内层络合反应和离子交换等.Because nitrified aerobic granular sludge exhibits high porosity,large surface area and decent separation capacity,aerobic granular sludge can be utilized as a biological adsorbent. In this study,nitrified aerobic granular sludge was used to remove Pb^2＋ from aqueous solution. Different initial p H values,initial Pb^2＋ concentrations,adsorbent doses and temperatures on Pb^2＋adsorption were evaluated as well. Three types of adsorption isotherms（ i. e.,by Langmuir,Freundlich and Redlich-Peterson models） were investigated.The results indicated that the equilibrium was well described by the Langmuir isotherm,predicting that the adsorption of Pb^2＋on nitrified aerobic granules was a monolayer adsorption. The R2 was 0. 9901,and the maximum adsorption capacity was 79. 58 mg/g at 25 ℃.Moreover,the equilibrium kinetic adsorption data were fitted to the pseudo-second-order kinetic equation with R2 values of 1. 0000,1. 0000 and 0. 9999 respectively. The relation coefficients（ RC）,which were 30. 706%,28. 019% and 24. 188%,were all under 50%,showing that the sorption of Pb^2＋was controlled primarily by intraparticle diffusion. Fourier transform infrared spectroscopy（ FTIR） results indicated that the active groups including O—H,N—H,CO,CC,C—OH and C—O—C were involved in Pb^2＋adsorption. Zeta potential analysis and p HZCProse from 2. 5 to 3. 1,demonstrating that inner-sphere adsorption happened for Pb^2＋adsorption on nitrified aerobic granules. The nitrified aerobic particles were well fitted by the good adsorption function on Pb^2＋; the adsorption mechanisms mainly included inorganic micro precipitation,surface complexation,inner-sphere complexation reaction and ion exchange.

关 键 词：硝化好氧颗粒污泥 吸附 PB^2+ 动力学 机理 

分 类 号：X703.1[环境科学与工程—环境工程]