元坝气田采出水电化学氧化法除氨氮工艺研究

Study on ammonia nitrogen removal from produced water of Yuanba gas field by electrochemical oxidation

关键词:  元坝气田  采出水  电化学氧化法  氨氮

Key words:  Yuanba gas field  produced water  electrochemical oxidation  ammonia nitrogen

摘要:

针对元坝气田低温蒸馏站现有处理工艺环节多、产泥量大等问题,拟引入电化学氧化法对采出水进行预处理,以除氨氮和降低有机物含量。通过小试优化了电化学氧化反应中电流强度、电解时间。结果 表明,采出水脱除硬度之后,当电解电流为1 200 A、反应时间为30 min时,氨氮去除率可达100%,同时有效降低废水有机物含量,此时吨水处理成本为7.56元。结合低温蒸馏站实际情况,中试采用“澄清软化+电解脱氨氮+反渗透+MVR蒸发”工艺,缩短处理流程,可有效降低药剂及污泥处置成本,为后续新建资源化站提供了理论和工艺设计支撑。 

Abstract:

The low temperature distillation station in Yuanba gas field is facing problems, such as too many units in the treatment process and large sludge production. Electrochemical oxidation method was proposed to pre-treat the produced water in Yuanba gas field to remove ammonia nitrogen and reduce the organic content. Based on bench-scale tests, the current intensity and electrolysis time in the electrochemical oxidation reaction were optimized and the results showed that the ammonia nitrogen removal rate could reach 100% and the organic content could be reduced effectively in the softened produced water, while the electrolysis current and the reaction time was set at 1 200 A and 30 min, respectively. Under such optimum conditions, the economic costs were determined to be RMB 7.56 yuan per ton. Considering the actual situation of the low temperature distillation station, the process of "softening-clarifying-electrical oxidation for ammonia nitrogen removal-reverse osmosis-MVR evaporation" was proposed and such improvement could shorten the treatment process and reduce the cost for chemical dosage and sludge disposal. This study provides theoretical and technical support for the establishment of subsequent produced water treatment station.