摘要
中国石化海南炼油化工有限公司的污水处理场采用了MBR工艺处理其炼油污水,设计处理能力为450m3/h。进入2008年以后,MBR膜在运行中出现膜通量下降较快的问题,造成实际生产能力不到设计值的1/2。通过分析,造成膜通量下降的原因为:系统中污泥龄较长,污泥颗粒细小,沉降性能差,容易形成生物黏泥;进水油含量超标以及吹扫风带油,造成油类污染;反洗频次较高,而且反洗水质得不到保证;系统膜组件的抖动风设计不合理,风量供应不均,风孔有堵塞现象;现场操作不当,导致膜丝间积存大量活性污泥,缠裹膜丝。采取了有针对性的措施:缩短污泥龄,降低活性污泥对膜的粘附性;调整清洗方案及药剂,采用1%氢氧化钠和0.3%次氯酸钠对膜件进行离线化学清洗;提高膜区风量,改进膜件底部的布气设施;优化工艺操作,控制进水油含量和吹扫风带油;加强溶气浮选的运行控制以及现场操作。措施实施后,MBR系统处理量由2006～2009年的180～220m3/h提高到2012年的140～160m3/h,跨膜压差控制在35～55kPa,膜通量的下降幅度远远低于前措施实施前,出水水质保持稳定。
Sinopec Hainan Refining and Chemical Co.,Ltd.′s sewage treatment plant uses MBR technology to treat refinery sewage,with a designed capacity of 450m3/h.In 2008,the MBR membrane′s flux dropped dramatically,resulting in the actual production capacity to drop to less than 1/2 of the designed value.After analysis,researchers found out the reasons for the decline in membrane flux:a.The long age and small grain of the sludge in the system had led to a deterioration of sludge settling properties and easily produced biofouling;b.the excessively high content of oil in the inflow water and the carrying of oil in the purging air had resulted in an oil contamination;c.the frequency of backwashing had been too high and the quality of water for backwashing was not stable;d.the vibrating air design of the membrane component was irrational,resulting in uneven supply of air and blockage of vents;e.improper operation had led to deposition of a large amount of active sludge between membrane silks,in turn wrapping up the membrane silks.Countermeasures taken included:Shortening sludge age and reducing the adhesiveness of active sludge to the membranes;adjusting cleaning plans and cleaning agents by adopting 1% sodium hydroxide and 0.3% sodium hypochlorite to conduct an offline chemical cleaning of the membrane component;raising air flow for the membrane area and optimizing the air distribution devices at the bottom of the membrane component;optimizing operating conditions to control the oil content of inflow water and the carrying of oil by purging air;and strengthening the control of dissolved air floatation operation and field operations.As a result of these measures,the treatment capacity of the MBR system rose to 140-160m3/h in 2012 from 180-220m3/h in 2006-2009,the trans-membrane pressure difference was controlled between 35 and 55kPa,the decline in membrane flux slowed dramatically compared to before the above measures were taken,and the quality of outflow water became stable.
出处
《中外能源》
CAS
2012年第8期96-99,共4页
Sino-Global Energy
关键词
污水处理场
活性污泥
膜生物反应器
膜丝
膜通量
跨膜压差
离线化学清洗
油含量
sewage treatment plant
active sludge
membrane bioreactor
membrane silk
membrane flux
trans-membrane pressure difference
offline chemical cleaning
oil content
