混凝沉降+生化工艺处理稠油污水外排试验研究

Experimental Study on the Coagulating Sedimentation and Biochemical Process for Discharged Heavy Oil Wastewater

含盐污水是稠油注汽开采过程中一种排放量大、污染严重的污水;含盐污水水质特性为高CODcr、高氯离子浓度和高矿化度等。以新疆油田六九稠油区供热站外排水为例,在深入分析外排水水质特征,了解水质现状,找准重点问题的前提下,结合现场实际情况及经济成本,制定了"混凝沉降-水解酸化-生物接触氧化"处理方案,并进行了试验。结果表明:系统水温控制在30~40℃,药剂PFS、PAM和Na_2CO_3的投加浓度分别为200、5和60 mg/L,水解酸化停留3 h,接触氧化停留6 h,最终出水中的CODcr、石油类、挥发酚等指标达到了GB 8978—1996《污水综合排放标准》中的第二类污染物最高允许排放浓度。

Saline wastewater is a kind of wastewater with a large amount of discharge and serious pollution in steam injection exploitation process of heavy oil. It has characteristics such as high CODcr,high chlorine concentration and high mineralization.Taking the discharged water of the heating station in 69 Heavy Oil Area of Xinjiang Oilfield as an example,on the premise of deeply analyzing the characteristics of discharged water quality, understanding the status of water quality and identifying key issues, and combined with field practice and economic cost, a treatment scheme of "coagulating sedimentation-hydrolysis acidification-biological contact oxidation" is developed and tested.The result shows that when the system temperature is 30 ℃ to 40 ℃,the dosage of PFS,PAM and Na_2CO_3 are respectively 200,5 and 60 mg/L.Hydrolysis acidification stays for 3 hours,contact oxidation stays for6 hours, and finally the indicators such as CODcr, petroleum and volatile phenol in the discharged water achieve the maximum allowable emission concentration of the second category of pollutants in GB 8978-1966 Wastewater Discharge Comprehensive Standard.