磁性多孔石墨烯串联臭氧净化水中有机微污染物的协同作用机制

Conventional treatment process and some novel technologies are flawed for the removal of organic micropollutants (OMPs) in drinking water treatment plant. Accordingly, it is proposed to replace the traditional process by using magnetic porous graphene combined with ozonation in this project for removing a variety of typical OMPs under the background of investigating the fate and transformation rules of OMPs in water. The purification efficiency of water are explored by adsorption kinetics, molecular dynamics simulation technology and biological toxicity test methods. Thus, synergism purification mechanism of natural organic matter and OMPs is revealed in complex water environment. While removing OMPs effectively, effective reduction of oxidation intermediate by-products and terminal disinfection by-products is studied, and its generation transformation path is systematically identified and completed additionally. This project aims to provide a theoretical basis for the removal of OMPs in water by the combination of renewable functionalized graphene-based materials and ozone, and to provide novel ideas for the deep purification of drinking water.

现有净水厂传统处理工艺及一些新型技术对于有机微污染物的去除还存有缺陷。据此，本项目以调查水中有机微污染物的迁移转化规律为背景，多种典型有机微污染物为研究对象，提出采用磁性多孔石墨烯串联臭氧氧化处理工艺替代传统工艺，通过吸附动力学、分子模拟技术及生物毒性测试等手段来探究水体的净化效率，揭示在复杂水体环境下有机微污染物与天然有机物的协同净化机制。研究在高效去除有机微污染物的同时，有效减少氧化中间副产物及终端消毒副产物的生成，并进行系统识别，从而完善其生成转化路径。本项目以期为可再生的功能化石墨烯基材料与臭氧联合作用对水中有机微污染物的去除提供理论依据，为饮用水的深度净化提供新思路。

本研究对常见石墨烯基材料进行优化，制备得到具有较大比表面积的磁性多孔石墨烯（MPG）。实验以个人护理品中广泛使用的广谱抗菌剂三氯生（TCS）作为OMPs代表，通过静态吸附实验发现MPG优于石英砂、石墨烯、GAC、PAC和MGO等吸附剂，对TCS的去除效率可以达到98%，且吸附过程符合准二级动力学。臭氧预氧化能有效去除TCS，但会产生以2,4-二氯苯酚为主的氧化副产物。本论文进一步提出MPG和臭氧氧化联合处理工艺（MPG+O3），经MPG短时吸附后进行臭氧氧化，能实现TCS的完全去除和氧化副产物的最小化。相比于预臭氧联合MPG吸附工艺（O3+MPG），MPG+O3具有总耗时和臭氧消耗量少等特点，且能够有效去除TCS，并有效控制中间副产物和DBPs的生成。MPG经简单再生后，仍然保持有对TCS的去除活性。此外，由于具有较大比表面积和丰富的孔结构，MPG对12种目标OMPs具有很好的去除效果。