生化出水EfOM对载锆复合树脂吸附除磷的影响与控制研究

Biological treatment is the most popular process for wastewater treatment. To inhibit the eutrophication and to achieve high water quality, it is essential to enhance removal of phosphorus in bio-effluent. Selective adsorption has been regarded as an important approach for enhanced removal of phosphorus from bio-effluent. The novel nano Zr (IV) oxide-resin composite has good prospects in the application on phosphorus removal because of its high capacity and selectivity, structural stability, ease of regeneration and cheap of preparation. In-depth study on the role of coexisting substances in bio-effluent in phosphorus removal is of fundmental significance to develop a new technology based on nanocomposite. In this proposal, we plan to characterize the biological effluent organic matter (EfOM), and elucidate its effect on adsorptive removal of phosphorus by the new composite. The underlying mechanism will be particularly focused on in terms of adsorption of pollutant on surface, stability of loaded nano-Zr(IV) oxide, and regeneration of the composite. The structure-activity relationship between Zr(IV)-resin composite and EfOM will also be established. On the basis of the above research, the basic approach for tunable phosphate adsorption will be proposed by both structural optimization of Zr(IV)-resin composite and optimization of pre-treatment. This program is believed to provide theoretical basis for enhanced removal of phosphorus from biological effluent by means of adsorptive technology with Zr(IV) oxide loaded resin.

生化法是应用最广泛的污水二级处理方法，其出水深度除磷对遏制富营养化、保障水质安全有重要意义。选择性吸附技术是实现生化出水深度除磷的重要手段。新型载纳米锆氧化物复合材料对磷吸附容量与选择性高、结构稳定、易于再生、价廉易得，应用前景良好，深入研究生化出水中共存物质对材料除磷性能的影响规律与作用机制，对于发展纳米复合材料除磷技术具有基础性意义。本项目拟系统表征生化出水有机物(Effluent organic matter, EfOM)组分性质，重点研究不同组分EfOM对复合功能树脂吸附除磷行为的影响规律，从污染物表面吸附、纳米锆氧化物稳定性、材料脱附再生性能的角度，系统阐明EfOM影响吸附除磷的性能与机制，揭示复合功能树脂与不同组分EfOM间的作用关系；在此基础上，通过复合功能树脂结构调控与预处理工艺优化，探索复合材料抗EfOM干扰的基本路线，为该材料用于生化出水深度除磷技术的开发提供理论依据。

吸附分离是市政污水处理厂二级出水深度除磷和资源化的一个重要技术选择，但二级出水EfOM可能对磷的吸附分离有重要影响。本项目以树脂基载锆纳米复合材料HZO-201为吸附剂，揭示了市政污水处理厂实际出水EfOM影响纳米复合材料吸附除磷的规律和关键组分。相较于、疏水中性/碱性（HPO-n/b）、过渡中性/碱性（TPI-n/b）和亲水中性/碱性（HPI-n/b）等有机组分，有机酸（OA）类物质对磷的吸附具抑制，其中小分子有机酸因其富含的带负电的酸性基团（羧基或酚羟基）或芳香类苯环结构，对磷的吸附量和吸附速率的影响最大。项目以没食子酸（GA）、单宁酸（TA）及腐殖酸（HA）为有机酸代表物，考察其对HZO-201除磷动力学、等温线及材料孔道结构的影响，揭示了有机酸影响与其分子大小之间的关系。通过FT-IR、XPS等技术对有机酸抑制磷吸附的机理进行了研究，结果表明，没食子酸分子量较小，并通过与季氨基直接竞争吸附位点削弱磷吸附效果，单宁酸分子量中等，主要通过孔道位阻效应阻碍磷的吸附，腐殖酸因分子量较大，往往难以进入吸附剂纳米孔道，因此对吸附效果影响不大。载锆纳米复合材料在研究中表现出良好的化学稳定性，锆纳米颗粒无溶出。本项目的研究为排除EfOM干扰、提高纳米材料吸附除磷应用性提供了技术参考。