电脱盐反冲洗废水稳定性研究  

Research on the Stability of Electrical Desalting Backwash Wastewater

作　　者：宁超 郎明 孙彦伟 谢亚利 张华 吴百春 Ning Chao;Lang Ming;Sun Yanwei;Xie Yali;Zhang Hua;Wu Baichun(PetroChina Daqing Refining and Petrochemical Company;China University of Petroleum(Beijing);CNPC Research Institute of Safety&Environment Technology)

机构地区：[1]中国石油大庆炼化公司 [2]中国石油大学(北京) [3]中国石油集团安全环保技术研究院有限公司

出　　处：《油气田环境保护》2023年第4期30-34,共5页Environmental Protection of Oil & Gas Fields

基　　金：国家水体污染控制与治理科技重大专项(2017ZX07402002)。

摘　　要：电脱盐反冲洗废水污染组成复杂,废水乳化带油严重,破乳分离困难。文章对比分析了电脱盐反冲洗废水与正常排水的水质特性,通过Zeta电位、表面张力和稳定性分析探究了体积稀释比对反冲洗废水稳定性的影响,考察了不同体积稀释比及转速与电脱盐反冲洗废水沉降或上浮速率的关系。结果表明:电脱盐反冲洗废水COD为55 785 mg/L,是正常排水的10.8倍,以非溶解性有机物为主;反冲洗废水Zeta电位为-2.5 mV,当体积稀释比为90%时,Zeta电位为-14.8 mV,随着体积稀释比降低,Zeta电位稳定在-14~-18 mV;反冲洗废水表面张力为42.20 mN/m,体积稀释比由100%变化至70%时,表面张力变化不大,但随着体积稀释比降低,表面张力呈增加趋势;反冲洗废水的不稳定性指数约为0.05,当体积稀释比从90%变化至1%时,不稳定性指数升高,而且转速由500 r/min增加至1 000 r/min时,不稳定性指数也有所升高;电脱盐反冲洗废水体积稀释比为80%~90%时,适于上浮处理;体积稀释比为20%~40%时,适于沉降处理。研究成果可为电脱盐废水混凝脱稳与气浮沉淀分离处理提供参考。The pollution composition of electrical desalting backwash wastewater is complex,severe emulsification and oil-carrying,making it difficult to demulsify and separate.In this paper,the water quality characteristics of electrical desalting backwash wastewater and normal drainage were compared and analyzed.The effects of volume dilution ratio on the stability of the electrical desalting backwash wastewater were explored through Zeta potential,surface tension,and stability analysis.The relationship between different dilution ratios,rotational speed and settling or rising velocity of the electrical desalting backwash wastewater was investigated.The results showed that the COD of the electrical desalting backwash water was 55785 mg/L,which was 10.8 times that of normal drainage,and it was mainly composed of non-dissolved organic matters.The Zeta potential of the backwash wastewater was-2.5 mV.When the volume ratio was 90%,the Zeta potential changed to-14.8 mV.With the decrease of the volume ratio,the Zeta potential remained stable in the range of-14 mV to-18 mV.The surface tension of the backwash wastewater was 42.20 mN/m.When the dilution ratio changed from 100%to 70%,the surface tension changed little.But withthe volume ratio decreased,the surface tension showed an increasing trend.The instability index of the backwash wastewater was about 0.05.When the dilution ratio decreased from 90%to 1%,the instability index increased.And the rotational speed increased from 500 r/min to 1000 r/min,the instability index also increased.When the dilution ratio of the electrical desalting backwash wastewater was between 80%and 90%,it was suitable for rising treatment,and when the dilution ratio was between 20%and 40%,it was suitable for settling treatment.The results of this study can provide reference for coagulation,destabilization and air floatation and sedimentation separation treatment of the electrical desalting wastewater.

关 键 词：电脱盐反冲洗废水 稳定性 ZETA电位 混凝 气浮沉降 

分 类 号：X703[环境科学与工程—环境工程]