How to treat wastewater with high salt content?
In order to obtain crystal salt from high-salt wastewater treatment, it needs to go through three stages: 1. separating monovalent salt and bivalent salt with nanofiltration membrane; 2. DTRO membrane is used for high salt water concentration; 3. The highly concentrated and concentrated brine is concentrated and crystallized in the evaporation crystallizer to obtain sodium chloride and sodium sulfate with relatively high purity.
In the first stage, if the total salt content of the wastewater is less than 15000 and COD is less than 15, roll test sodium filter membrane can be considered. If it is more than 15000, we can consider using Jinzheng DTNF to separate sodium chloride and sodium sulfate.
The second stage is the key stage of brine concentration. The concentration efficiency of wastewater in this stage is directly related to the amount of water entering the evaporation crystallization, thus affecting the operation cost. Jinzheng DTRO membrane can be concentrated to 145g/L of sodium chloride solution and 201g/L of sodium sulfate solution. The performance has been verified by many cases and the operation effect is very stable.
In the third stage, evaporation crystallization or freezing crystallization is required according to the physical and chemical properties of the two salts.