元坝低温蒸馏站产出水深度处理工艺研究

Research on Advanced Treatment Process of Produced Water in Yuanba Low Temperature Distillation Station

针对元坝气田低温蒸馏站产出水COD和挥发酚等指标不合格问题,开展了低温蒸馏站产出水相关试验研究,确定了低温蒸馏站产出水深度处理工艺。利用三维荧光和气质联谱方法对COD组分进行分析,根据分析结果开展了室内生化实验和芬顿氧化实验,确定了芬顿氧化的最佳工艺参数,即pH值控制在3~4,H2O2:COD质量比控制在3∶1~4∶1,H2O2:Fe2+摩尔比控制在5∶1~40∶1,反应时间在3 h。根据室内实验结果,开展了现场中试试验,采用芬顿高级氧化能够有效去除低温蒸发装置产出水中难降解的COD和挥发酚等有机物;采用芬顿高级氧化+反渗透工艺能够实现最终出水水质达到Q/SH 0104—2007《炼化企业节水减排考核指标与回用水质控制指标》中循环冷却水补充用水水质要求。该工艺在油气田采出水深度处理过程中有着很好的应用前景。

In view of the problems that the indicators,such as COD and volatile phenol,of the produced water in the low temperature distillation station of Yuanba Gas Field are unqualified,relevant experimental studies about produced water of low temperature distillation station are carried out,so as to determine its advanced treatment process.The COD components are analyzed by using the method of three-dimensional fluorescence and GC-MS method.According to the analysis results,the laboratory biochemical test and Fenton oxidation test are carried out,and the optimal process parameters of Fenton oxidation are determined,that is,the pH value should be 3 to 4,the mass ratio of H2O2 and COD should be 3:1 to 4:1,the mole ratio of H2O2 and Fe2+should be 5:1 to 40:1,and the reaction time should be within 3 hours.According to the laboratory test results,the on-site pilot test is carried out.Using Fenton advanced oxidation method can effectively remove organics such as COD and volatile phenol from the produced water of the low temperature evaporation device.Using Fenton advanced oxidation method and reverse osmosis process can finally make the water quality of produced water reach the requirements for the supplement quality of circulating cooling water in Assessment Index of Water Saving and Emission Reduction and Reuse Water Quality Control Index of Refining and Chem-ical Enterprises(Q/SH 0104-2007).The process has a good application prospect in the advanced treatment process of produced water in oil and gas fields.