厌氧颗粒污泥对纳米TiO_2的吸附特性研究  

Adsorption Characteristics of TiO_2 Nanoparticles on Anaerobic Granular Sludge

作　　者：李慧婷 崔福义 

机构地区：[1]哈尔滨工业大学环境学院,黑龙江哈尔滨150090 [2]哈尔滨工业大学城市水资源与水环境国家重点实验室,黑龙江哈尔滨150090

出　　处：《中国给水排水》2017年第23期87-93,共7页China Water & Wastewater

基　　金：国家自然科学基金资助项目(51078102)

摘　　要：分析了厌氧颗粒污泥吸附nano-TiO_2的过程,探讨了不同p H值及离子强度下厌氧颗粒污泥吸附nano-TiO_2的动力学和热力学特征。结果表明,厌氧颗粒污泥对nano-TiO_2的吸附符合准二级动力学方程。相较于p H值,离子强度对吸附过程的影响更显著,且nano-TiO_2在高离子强度下的扩散和吸附速率更低。液相离子强度升高或p H值接近等电点都会增加nano-TiO_2的吸附量。Langmuir吸附等温线模型能够更好地拟合吸附过程,且该吸附可自发进行,随着p H值接近等电点,吸附自发性逐渐增加。厌氧颗粒污泥对nano-TiO_2的吸附以化学吸附为主,同时存在多种机制共同作用。另外,环境条件对水中纳米颗粒的归趋有显著影响,其在活性污泥中的富集对污水处理效能可能产生潜在危害。This study focused on kinetics and aerobic granular sludge （AGS）. The kinetics results equilibrium adsorption of TiO2 nanoparticles by an- showed that adsorption of TiO2 nanoparticles on AGS could be fitted to a pseudo-second-order kinetic model. Compared to the pH values effect, the initial ion strength （IS） played a more important part on TiO2 nanoparticles adsorption, since it was observed that more TiO2 nanoparticles were adsorbed to the AGS at high IS, regardless of the solution pH. The Lang- muir model was found to better describe the adsorption data than Freundlich model, and the adsorption process was apparently irreversible. The free energy of the adsorption suggested that the adsorption process was spontaneous, and the pH values close to isoelectric point of TiO2 nanoparticles could improve the spontaneity. Chemical adsorption could be the main mechanisms were also involved in the TiO2 nanoparticles fate and transport of nanoparticles could be influenced by adsorption mechanisms, while other interaction adsorption on AGS. The results proved that the the solution chemistry, which may have raisedconcerns about the potential adverse effect of nanoparticles accumulated in the sludge.

关 键 词：厌氧颗粒污泥 纳米TIO2 吸附动力学 PH值 离子强度 

分 类 号：X703[环境科学与工程—环境工程]