Seeking help in treating high-salt, low-COD wastewater
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The wastewater contains about 10% salts (mainly sodium chloride and similar substances), with a slightly alkaline pH, and its COD level is around 1000. What is the most appropriate method for treating this wastewater? {:2_30:} I read online that using MVR results in lower energy consumption. Does COD have a significant impact on this process? Can other treatment methods, such as membrane technology, be used? How is the final concentrate usually handled? How much will it cost approximately?
It can be concentrated and crystallized using MVR and then sold as industrial salt. It seems that the membrane cannot achieve the critical concentration level; I’m not very familiar with this. Evaporation crystallization is definitely necessary in this process, so there’s no need to use a membrane when MVR is employed
I don’t know much about MVR treatment; could some expert provide some information for me to learn about it? Using membrane technology is likely not feasible; high COD levels can cause rapid membrane fouling. I’ve seen systems using membrane technology to treat centrifugation mother liquor from the chlor-alkali industry, where the membranes became clogged after just a few uses. However, it’s not clear whether there are any membranes with better resistance to fouling available these days. An ordinary RO membrane with a 10% salt content won’t work; DTRO might still be feasible, but it’s uncertain whether it can handle such high COD levels.
Does COD have an impact on MVR?
What is the appropriate COD value for membrane processes? To what extent can wastewater generally be concentrated?
First, examine the composition of your COD as well as other components in the wastewater to determine whether they are toxic and whether they are easy to degrade. Second, membrane treatment is not recommended; if the wastewater composition is suitable for biological treatment, evaporation can be used first followed by biological treatment. If there are bubbles in the water, some pre-treatment steps should be taken. Third, regarding the salt produced through evaporation, you can contact local or nearby industrial salt manufacturers and distributors. Finally, it’s important to note that not all treatment processes are suitable for your wastewater 100%; we can only suggest processes that might work, such as biological treatment, anaerobic treatment, Fenton’s process, electrolysis, UV+H2O2 treatment, A/O process, or bio-bed treatment. These processes can handle wastewater with relatively low COD levels, but it’s still necessary to consider factors such as the toxicity of the wastewater, the presence of high levels of sulfate, the presence of long-chain organic compounds, and the biodegradability of the substances involved. If possible, provide more detailed information such as COD, BOD, SS, TN, TP, and the main components of the wastewater
This post was last edited by slll611 on 2016-9-28 at 21:32. MVR can be used for the initial treatment, and the resulting concentrated solution can be processed using our company’s special evaporation and drying equipment, which enables the recovery of over 90% of the moisture present in the MVR-concentrated solution; the treatment outcome will be very good. If you need it, I can send you some information on our equipment; you can take a look and get an idea.
Both biological methods and advanced oxidation methods can be used for treatment, and the costs of both approaches are low.
10% salt content is suitable for use with MVR; the cost is approximately 20–30 yuan per cubic meter (depending on your electricity price). As for COD, it depends on what it is and what its boiling point is It doesn’t matter if it’s non-volatile.
Apart from the evaporation method, the other methods can only reduce the COD value, right? Is the water discharged after the COD level has been reduced? More inclined to MVR
I contacted an MVR company; it allows for direct crystallization. Do you need any other equipment?