三维电极耦合臭氧技术处理油田压裂返排液

Treatment of oil field fracturing flowback wastewater based on 3D/O3 process

构建了一种活性炭三维电极耦合臭氧(3D/O3)的反应体系,研究了其对胜利油田压裂返排液COD的去除效果,探究了3D/O3体系的反应机制,考察了电流、臭氧浓度等过程参数对COD去除性能的影响.压裂返排液经3小时3D/O3处理后,COD去除率可达到78%,且在多个多周期运行后保持在60%以上.与之相比,单独三维电极和臭氧氧化仅能去除37%和17%的COD.研究结果表明,3D/O3体系可有效耦合活性炭吸附、电化学氧化、催化臭氧等多种反应机制,高效产生·OH氧化降解压裂返排液中的有机污染物和原位再生活性炭,有望为油田压裂返排液提供一种有效的处理技术.

In this study,a three-dimensional electrode/ozone(3D/O3)system was developed by combining ozonation with electrolysis using granular activated carbon(GAC)as the particle electrodes,the developed 3D/O3 system was then used to treat the fracturing flowback wastewater from Shengli oil field.The reaction mechanism of the 3D/O3 system and the effects of process parameters(e.g.,current,ozone concentrations)on COD removal were investigated systematically.Results show that COD removal efficiency reached^78%after 3h of the 3D/O3 treatment,and could be maintained stably above 60%during 8 cycles of operation.In comparison,3D electrolysis and ozonation alone removed only^37%and 17%COD under similar reaction conditions.These results indicate that the 3D/O3 system effectively couples activated carbon adsorption,electrochemical oxidation,and catalytic ozonation to enhance hydroxyl radical generation to oxidize organic pollutants in the fracturing flowback wastewater and regenerate activated carbon.Therefore,it may provide a promising method to remove COD in hydraulic fracturing flowback wastewater.