Technical assistance: Selection of treatment methods for saline wastewater
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This post was last edited by hesonchang214 on 2009-9-29 09:30. The salt concentration in the wastewater generated by our manufacturing process is 10%; we would like to recover this salt. After researching, we found two methods: membrane filtration and direct evaporation crystallization. We’re not sure which one to choose – could anyone please offer some advice?
Is salt water clean? Are there no other organic or inorganic impurities? Reverse osmosis won’t work. Salt recovery? What’s the use?
The quality requirements for reverse osmosis brine are too high; direct evaporation is a more reasonable approach.
Direct evaporation is possible, but it’s unclear whether there are organic impurities in the water; if so, it will be difficult
This post was last edited by hesonchang214 on 2009-9-29 09:31. If there are no other impurities in the saltwater, it’s still better to simply evaporate it – it saves time and effort, and the result is the same anyway.
A detailed comparison of the two options is required to draw a conclusion: analysis can be carried out using the SWOT matrix from aspects such as process stability, treatment costs, removal efficiency, and operability, which makes it easier to make a judgment.
How much is the wastewater volume? If there is too much, it is recommended not to evaporate it directly ； If there are organic substances in the wastewater, it is also recommended not to evaporate it directly ； When using reverse osmosis, it also depends on the amount of wastewater.
Such a high salt content can only be reduced by evaporation. It is possible to specify the water volume, the types of salts present, and then provide a specific plan.
What is the purpose of recovering salt with a content of 10%? Direct evaporation is a more reasonable approach; of course, impurities are inevitable. Using reverse osmosis is certainly good, as it yields pure water of high quality, but the treatment and investment costs are high.
What kind of salt is 10%? Is there any value in recycling it? Multi-effect evaporation has high costs and expenses, but it can be completed in one go. The concentrate from reverse osmosis still needs to be further treated. It seems that there are now newly developed halophilic bacterial strains that can also handle such wastewater
This post was last edited by cdpulin on 2010-10-8 at 11:11. Please indicate the volume of water, the salts it contains, as well as whether there are any impurities or organic substances present, so that an accurate assessment can be made. Direct evaporation without organic matter is preferable.