Beginner seeking advice on treatment methods for high-salt coking wastewater
Thread Content
Are there any other viable options besides using multi-effect evaporators for treating coking wastewater with a COD of 17,000 mg/L and total salt content of 16,000 mg/L? A newcomer seeking advice; I’m not very familiar with this yet
Hello, even when using an MVR evaporator for evaporation, effective pre-treatment is necessary to remove COD. Large-pore adsorption resins can be employed for this pre-treatment purpose, to reduce the COD in the wastewater and eliminate large molecular organic substances before proceeding with the evaporation process.
The COD and total salt content in this coking wastewater are very high; it is recommended that the original poster conduct a detailed analysis of the components of COD and those of the total salt. Does total salt contain a large amount of organic salts? If so, biochemical treatment can remove most of the COD and total salts, eliminating the need for evaporation. If they are all inorganic salts, the biochemical effects of those salts will be reduced, requiring an extended residence time in the biochemical unit; at the same time, the shock resistance of the biochemical system will decrease.
What is the daily water treatment volume? There is a pressure-reduction evaporation system designed specifically for the treatment of wastewater with high salt content and high COD levels.
First, it is necessary to analyze the components of COD and the types of salts to determine what the main pollutants are. If there is oil present, almost all evaporation processes can be avoided, unless pre-treatment is carried out first. When the salt content exceeds 10,000, biological treatment becomes necessary, but the load is high, which places significant demands on the maintenance of the biological system. If the salts contain a large amount of sulfate ions and metal ions, almost all membrane treatment processes should be avoided until these ions are removed. To decide on the appropriate treatment process, it is advisable to consult a professional company for a simple analysis; in addition, it is important to determine as precisely as possible the composition of the water, especially regarding salts
The high osmotic pressure resulting from the high salinity of wastewater reduces the nutrient uptake of microbial communities, thereby lowering the efficiency of pollutant treatment. Generally, when using the activated sludge method to treat organic wastewater, the salinity of the wastewater should not exceed 5-6%; otherwise, the efficiency of wastewater treatment will **decrease, or even the microorganisms used in the process may die. Have you guys considered it?!
What was said upstairs makes sense. First of all, what are the components included in a COD test? What type of wastewater is it, and what are the parameters regarding salt content? Please advise.
For the evaporation process, depending on the plant’s energy structure and cost composition, multi-effect or MVR can be chosen； For evaporation equipment, falling-film or forced-crystallization evaporators are selected based on the evaporation conditions at different concentrations. Select appropriate materials based on different operating conditions and material compositions. Coking wastewater has a complex composition, and special attention must be paid to elements such as COD and scaling components. Otherwise, the equipment’s operational life will be very short. The above is for reference only during design.
What was said upstairs is very good; it is recommended to use EDI first to separate salt from COD, and subsequently MVR+TVR can be employed. After evaporation, the distilled water along with the separated COD can be subjected to biochemical treatment.
It can be used directly as circulating water.
The salt content in your wastewater isn’t high. What type of wastewater is it? Let me see if I can handle it