页岩气田压裂返排液电化学臭氧耦合处理技术实验研究

Experimental Research on Electrochemical Ozone Coupling Treatment Technology of Fracturing Flowback Fluid in Shale Gas Fields

针对页岩气田压裂返排液高COD、高氯化物的特点,首先开展了多种高级氧化处理技术去除TOC的室内实验,初步优选出絮凝+电催化臭氧氧化组合工艺对TOC的去除效果最好。然后开发了电絮凝电催化臭氧氧化耦合处理技术,分别在不分反应室、分反应室两种情况下开展TOC去除实验,实验结果显示不分室情况下,TOC去除率达80%,分室情况下,TOC去除率达95%。针对分反应室条件下,进行了电絮凝电催化臭氧耦合处理(EC/EP)工艺参数优选,结果表明:Al板为阳极,C-PTFE为阴极,阳极室反应30 min,阴极室反应30 min,氧气通量为500 mL/min,臭氧浓度为80 mg/L,电流强度为400 mA时,对TOC的去除率最好。

In view of the characteristics of high COD and high chloride in fracturing flowback fluids in shale gas fields,laboratory experiments of various advanced oxidation treatment technologies to remove TOC was firstly carried out,and the flocculation+electrocatalytic ozone oxidation combined process with the best TOC removal effect was preliminarily selected.Then,the electroflocculation electrocatalytic ozone oxidation coupling treatment technology was developed,and TOC removal experiments were carried out in two cases without and with dividing the reaction chamber.The experimental results showed that the TOC removal rate was 80%without dividing the reaction chamber,and 95%in the case with dividing the reaction chamber.The process parameters of electroflocculation electrocatalytic ozone coupled treatment(EC/EP)were optimized under the conditions of dividing the reaction chamber.The results showed that,when Al plate was the anode,C-PTFE was the cathode,the reaction in the anode chamber was 30 min,the reaction in the cathode chamber was 30 min,and the oxygen was used for 30 min,the flux was 500 mL·min-1,the ozone mass concentration was 80 mg·L^(-1),and the current intensity was 400mA,the removal rate of TOC was the highest.