改性硅藻土复合混凝剂处理深度采油废水

Treatment of oilfield wastewater by modified diatomite with coagulants

某油田深度采油废水中含有大量残油,粘度大、乳化程度高、油水分离困难,本实验采用改性硅藻土吸附和无机混凝剂混凝相结合以处理深度采油废水。结果表明,对于含油浓度为250～350 mg/L的石油废水,用强化吸附方法,吸附剂投加量为1.5 g/L,优化实验条件下除油率可达到75%;采用强化混凝的方法,PAC在投药量为200 mg/L的情况下除油率可达到87%;采用强化吸附-混凝联合处理的优化方法,投加0.7 g/L吸附剂+PAC 200 mg/L,除油率>95%,明显高于吸附和混凝单独处理效果,大大改善了出水水质。

The treatment of the oilfield wastewater is difficult because of its high concentration of oil, high viscosity, and emulsification. We investigated the treatment of the oilfield wastewater by modified diatomite with coagulants. The results demonstrated that when the oil concentration of the oilfield wastewater was 250 - 350 mg/ L, the oil removal rate could reach 75% with 1.5 g/L modified diatomite by the enhanced adsorption. The re- moval rate can achieve 87% with the addition of 200 mg/L PAC by the enhanced coagulation. If adding 200 mg/ L PAC and 0.7 g/L modified diatomite into the same oilfield wastewater, the oil removal rate can achieve 95% or even higher. Therefore, the treatment of oilfield wastewater by modified diatomite with coagulants was obviously more efficient than adsorption or coagulation alone.