粉煤灰用于含聚污水预处理及其微波再生机制研究

Extensive emissions of polymer-flooding wastewater (PFW) and coal fly ash (CFA) have caused severe effect on the industrial production and environment. High efficient treatment and recycling of PFW and CFA becomes a consensus. This project will apply acid-modified CFA catalyzed Fenton-like process to pretreat PFW. The dynamic process conditions of pretreating PFW will be optimized gradually by static experiment, dynamic experiment and joint experiment of Fenton-like process with conventional oily wastewater treatment equipment. The kinetic model, the path and law of polyacrylamide (PAM) degradation will be established by investigating the variation of concentrations of PAM and its degradation products with time, and then the effect of PAM degradation process on viscosity of PFW will be discussed. Through establishing the mathematic relationships among the apparent microwave absorption capacity (MAC) of acid-modified CFA catalyst, the MACs of metallic oxides and minerals in the catalyst, the effect of metallic oxides on MAC of the catalyst and the law of MAC of different CFA catalysts will be discussed. Based on this, the deactivated catalyst will be regenerated by microwave irradiation: the regeneration process will be optimized and the regeneration capacity will be examined. By comparing the physical-chemical properties of deactivated catalyst (by SEM, XRF, and XRD etc.) before and after regeneration process, the mechanism of regenerating deactivated catalyst will be scientifically clarified. The results of this project will provide the support of theory and technology both for the recycling of CFA and effective treatment of PFW, and has important environmental significance and socioeconomic performance.

含聚污水和粉煤灰大量排放对工业生产和环境造成严重影响，高效处理与回用两类污染物已成共识。本项目将酸改性粉煤灰催化类Fenton应用在含聚污水预处理中。通过静态实验、动态实验和类Fenton与常规采油污水处理设备联合实验，逐步优化污水预处理动态工艺条件；通过研究聚丙烯酰胺(PAM)和降解产物浓度随时间变化，建立PAM降解动力学、降解途径和规律，进而探讨PAM降解过程对污水黏度的影响。通过建立酸改性粉煤灰催化剂表观微波吸收性能、所含金属氧化物和矿物成分微波吸收性能之间数学关系，探讨金属氧化物对催化剂微波吸收性能的影响和不同粉煤灰催化剂微波吸收性能的规律；基于此，利用微波辐射再生失活催化剂，优化再生工艺，考查再生性能；利用SEM、XRF、XRD等方法，通过对比催化剂再生前后物化性质，科学阐明催化剂再生机制。该项目可为粉煤灰回用和含聚污水有效处理提供理论和技术支持，具有重要环境意义和社会经济效益。

粉煤灰是燃煤热电厂产生的主要固体废弃物，含聚污水是油田产生的主要液体废弃物，二者的存在给社会生产和环境保护带来了较大压力。本项目聚焦于含聚污水预处理和粉煤灰基类Fenton催化剂的微波再生，具体研究内容包括（1）含聚污水预处理工艺、PAM降解动力学与降解途径，（2）酸改性粉煤灰催化剂微波吸收性能与规律，（3）失活酸改性粉煤灰催化剂微波再生工艺、再生性能与再生机制三方面研究。通过本项目，项目组开发了一种有效的粉煤灰基类Fenton催化剂，使H2O2可以以较高的分解率分解成·OH，从而有效预处理含聚污水；项目组通过表征类Fenton催化剂不同阶段的物化属性，探讨了催化剂的制备机制、失活机制以及催化剂与微波的响应机制，为含聚污水的有效预处理提供前期基础。粉煤灰经过改性后，比表面积和孔体积都有了一定的提升，分别在30%和56.4%左右，另外，鉴于大量微孔被打开，平均孔径降低了17.3%，这对于粉煤灰基类Fenton催化剂吸附性能和催化性能的提高具有重要作用；含聚污水中PAM和COD去除率分别在90%和60%以上，废水处理效果良好；本项目制备的粉煤灰基类Fenton催化剂具备较好的催化稳定性，在保证催化效果前提下，可以使用6次以上，在制备费用占据优势的前提下，与同类催化剂的稳定性处于同一数量级。总体而言，本项目可同时为粉煤灰基类Fenton催化剂和多金属类Fenton催化剂的研发与制备提供理论基础，对于含聚污水的有效预处理具有重要的现实意义，同时可为燃煤热电厂中的粉煤灰的合理高附加值回用提供一条可选途径。