Discuss the treatment processes for cotton pulp black liquor wastewater
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The black liquor emitted during the cotton pulp production process has a high COD level, high color intensity, and high alkalinity as well； At present, almost no one uses alkali recovery; if it is used, the number of systems required is too large and the investment is also high ； If chemical treatment is used, the amount of chemicals required is high, resulting in high operating costs; moreover, the effectiveness may not be good. I’ve heard that membrane treatment can be used, but I’m concerned about membrane clogging and reduced treatment capacity. We specially invite our peers to participate in the discussion on this topic! ! !
Salts, mineral oils, vegetable oils, as well as elements such as calcium and magnesium have a significant impact on membrane scaling and clogging; it is recommended to use sand filtration, carbon filtration, ultrafiltration, and RO.
The pH value of cotton pulp black liquor is 12–13, which is not acceptable under normal ultrafiltration or reverse osmosis membrane conditions. Ultrafiltration uses alkali-resistant membranes, while reverse osmosis does not use such membranes, right?