The biological pollution of reverse osmosis element membrane mainly comes from the seepage water body, and the pretreatment may also come from pollutants. Generally speaking, biological contamination is a relatively slow overall process. In many cases, it is difficult to detect, and sometimes it is related to other factors.
1. Symptoms of reverse osmosis element membrane pollution
(1). Reduce the diffusion coefficient of reverse osmosis membrane cartridge;
(2). The seepage temperature and the transmembrane pressure difference gradually expand;
(3). The salt removal rate of the membrane slowly decreases;
2. Cumulative hazards of reverse osmosis element membrane pollution
(1). The cleaning and maintenance costs of reverse osmosis system increase;
(2). The effluent water body is significantly affected;
(3). The service life of reverse osmosis membrane cartridge is significantly reduced.
3. Pretreatment and disinfection
In order to better avoid biological pollution, it is necessary to minimize the turbid water area on the pipeline to prevent the application of carbon filter devices. Before installing reverse osmosis element membrane, reverse osmosis system and its equipment must be disinfected and sterilized, continue to run after operation, and grow and develop biofilms when shut down.
4.The method of controlling microbial contamination of reverse osmosis element membrane
(1). Disinfectant is applied to the method of online cleaning or offline cleaning;
(2). After RO reverse osmosis occurs, reasonable cleaning methods must be adopted;
At this stage, for LFC and PA membranes, there is no more extreme disinfectant at this stage. The membrane disinfectant must have the following characteristics:
①. The reverse osmosis membrane will not be destroyed;
②. Ability to control and eliminate all types of bacteria and biofilms;
③. In physics, biofilms that have already been produced can be destroyed;
④. Non-toxic and easy to operate;
⑤. It can be biologically dissolved and easy to handle;
⑥. Easy to detect and fill;
⑦. It can disinfect and sterilize the water production side;
⑧. The price is relatively low and cost-effective.