反渗透膜运行的问题分析

针对中国石油独山子石化公司乙烯厂污水深度处理装置中反渗透膜系统故障问题进行了分析,初步分析表明由于进水水质不合理,RO膜表面会发生无机盐的结垢及有机物的污堵,导致产水量降低,压差上升,能耗增加,需要频繁的膜清洗,同时指出反渗透膜清洗的不足之处,最后在现有基础上提出了整改建议,一是在反渗透进水口处增加加酸点降低反渗透进水的pH值到6.0～7.5,降低HCO3-质量浓度后再进行阻垢处理,这样才能降低朗格利尔饱和系数,有效抑制结垢;二是实施保护性清洗措施;三是前段水质预警监测措施。现场应用情况显示效果较好。

Analysis of Problems in Operation of Reverse Osmosis Membranes

The troubles in the reverse osmosis system of waste water treatment plant of PetroChina Dushanzi Petrochemical Company are analyzed.The results of preliminary analysis indicate that the reverse osmosis（RO） membranes suffer from membrane fouling by inorganic salts and organic materials,which is resulted from off-spec water input of RO system.The membrane fouling bring numerous problems,e.g.,decrease of water production,the rise of pressure,increase of energy consumption and requirement of frequent membrane cleaning.The shortcomings of cleaning of reverse osmosis are discussed.The correction measures are proposed based upon the analysis：（1） acid addition is provided at the water inlet of reverse osmosis to reduce the pH value（6.0 ～ 7.5） and HCO3-and fouling inhibition is adopted.These will reduce Langelier saturation index and control the fouling.2.Protective cleaning measure is taken.（3） The inlet water quality is monitored and controlled.Good results have been achieved after implementation of these measures.