破胶絮凝-预氧化-深度氧化处理压裂返排液

Gel Breaking-coagulation-pre Oxidation-advanced Oxidation Treatment of Fracturing Flow-back Fluid

以四川德阳某气田作业现场的压裂返排液为研究对象,通过对其水质特征、治理现状进行分析,提出了破胶絮凝-预氧化-深度氧化的处理工艺.通过实验研究,确定了性能优良的破胶絮凝剂、预氧化剂及Fenton氧化体系;并得出最佳实验条件：CaO、Al2（SO4）3及FeSO4的投加量均为5 000 mg/L;在不调节出水pH、加入预氧化剂高锰酸钾500 mg/L、反应时间15 min的条件下,CODcr去除率达到58％;调节废水pH至3.0～4.0,再采用Fenton氧化处理,其投加量为H202 （30％）6 mL/L、及FeSO4·7H2O 5 000 mg/L,反应时长2h.采用上述处理工艺,处理后废液的主要污染指标CODCr降低了79％,从而为达标处理创造了条件.

The research of fracturing flow-back fluid of a gas field workplace in Sichuan Deyang is focus on.The quality characteristics and treatment situation of the fluid are analyed,and investigated the treatment process of gel breaking-coagulation-pre oxidation-advanced oxidation.Through the experimental study,the excellent-property system of gel-breaker,inorganic coagulants,pre-oxidants and Fenton oxidation have been established and the optimum experimental condition has been concluded as follow：respective dosing quantity of 5 000 mg/L of calcium oxide,aluminum sulfate and ferrous sulfate ; keep constant of the water pH,adding pre-oxidant potassium permanganate 500 mg/L,CODcr removal rate reached 58％ under the reaction time 15 min; changing the water pH to 3.0 ～4.0 and using Fenton oxidation treatment with the dosage of H2O2 （30％）6 mL/L and FeSO4 · 7H2O 5 000 mg/L,CODCr removal rate reached 79％ after the reaction time 2 h.Overall,the major pollution indicator of CODCr in waste liquor is effectively reduced by means of those treatment processes,which create the condition for standards.