油田压裂废水的Fenton氧化-絮凝回注处理研究

Reinjection treatment of oilfield fracturing wastewater by Fenton oxidation—flocculation

针对油田压裂作业废水黏度高、浊度大、含油量高的特点,采用Fenton氧化-絮凝处理方法对压裂废水进行回注处理研究,探讨了废水的pH值、Fenton试剂和絮凝剂投加量、絮凝剂加药时间隔等因素对压裂废水氧化和絮凝处理效果的影响.结果表明:当压裂废水pH值为3.0、φ(H2O2)和ρ(FeSO4)分别为0.2%和20mg/L、PAC和PAM质量浓度分别30mg/L和5mg/L、絮凝剂加药时间间隔为30s、处理后水pH值调至7.5时,处理后压裂废水中的悬浮物含量和含油量分别为2.5mg/L和5.22mg/L,平均腐蚀速率和细菌含量分别为0.0110mm/a和101个/mL,达到油田回注水的水质标准.

The viscosity,turbidity and oil content of oilfield fracturing wastewater are all high,and in order to reuse the fracturing wastewater as reinjection water,the reinjection treatment of the oilfield fracturing wastewater by Fenton oxidation—flocculation is studied.The effects of the pH value of the wastewater,the input dosages of fenton reagents and flocculants and the time intervel between adding organic flocculant and inorganic flocculant on the treatment result of the fracturing wastewater are discussed.The results show that the suspended solids and oil concentrations of the treated water are 2.50 mg/L and 5.22 mg/L respectively,and the average corrosion rate and the bacterial quantity of it are 0.011 0 mm/a and 101个/mL separately when the pH of the wastewater is 3.0,the volume fraction of H2O2 is 0.2%,the concentration of FeSO4 is 20 mg/L,the concentrations of PAC and PAM are 30 mg/L and 5 mg/L separately,and the pH value of the treated wastewater is adjusted to 7.5.The main quality parameters of the treated wastewater can reach to the water quality standard for oil field injection water.