After offline chemical cleaning of the first-stage reverse osmosis system, the pressure difference increases rapidly – it rose by 40 kPa in just one week. Could some experienced colleagues help analyze this?
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After offline chemical cleaning of the first-stage reverse osmosis system, the pressure difference increases rapidly – it rose by 40 kp in just one week. Please help analyze this situation, experts. The alkali washing + acid washing method is employed, likely due to colloidal and microbial blockages; below is the reverse osmosis operation diagram after cleaning. .
There are a few things that need to be understood: 1. What type of water is the source? It determines the content of original cement sand and microorganisms. 2. What is the filtration condition before the RO membrane? For thorough purification, it is best to have both coarse sand filtration and fine sand filtration. The raw water is first treated with ferric chloride to facilitate flocculation, after which it passes through coarse sand; subsequently, sodium hypochlorite is used to kill bacteria and algae, followed by passage through fine sand. Hydrogen sulfite or activated carbon is then used to remove free chlorine, and an additional safety filter is used as well to ensure greater reliability. 3. What type of scale inhibitor is used for RO membranes? Could it become a nutrient for microorganisms? 4. Is there hydrogen peroxide treatment for sterilization after acid and alkali washing? Considering the following aspects, I hope this will be helpful to you……
In my opinion, the design of reverse osmosis systems is now quite mature, and pre-treatment is generally an essential part of such designs. You can check the following: 1. Inadequate manual cleaning will cause the pressure difference to rise rapidly; a decrease in the pressure difference after cleaning is only a superficial phenomenon. 2. Are the added chemicals within a reasonable range, regarding the amounts of reducing agents and scale inhibitors? One is whether the medication has been changed recently (either to a different manufacturer or to a different batch from the same manufacturer). 3. Whether the residual chlorine level is adequate during the pre-treatment to reverse osmosis process.
Okay, thank you, senior master. I’ll carefully summarize things, explore them thoroughly, and observe further
There should be a filter before reverse osmosis to prevent a rapid increase in pressure difference