Zero emission technology adopts a combination of ultrafiltration membrane filtration technology, reverse osmosis membrane concentration technology, hard and silicon removal technology, mineralization treatment technology, nanofiltration salt separation technology, evaporation crystallization technology and so on.

The discharged wastewater first goes through a series of physical and chemical and biochemical treatment to reach the direct discharge standard, and then filtered by ultrafiltration membrane. The ultrafiltration membrane adopts hollow fiber ultrafiltration membrane, and the filtration pore size can reach 0.03 microns. It is mainly used to remove suspended matter in wastewater and ensure the normal operation of subsequent reverse osmosis membrane concentration system.

The reverse osmosis membrane concentration system determines the multi-stage reverse osmosis membrane concentration according to the salt content of the wastewater, which is roughly divided into three levels, the first level is concentrated by brackish water membrane, the second level is concentrated by seawater desalination membrane, and the third level is concentrated by DTRO high-pressure membrane. Through the multi-stage reverse osmosis membrane concentration system, the proportion of concentrated liquid in wastewater is controlled below 5%, which reduces the capacity of post-stage evaporation crystallization system and reduces the treatment cost.

The hard silicon removal system is mainly used to reduce the hardness and silicon content of wastewater solution, meet the water intake requirements of the membrane concentration system and evaporation crystallization system, avoid scaling and fouling, affecting long-term normal operation. In addition to hard silicon removal technology mainly adopts the combination of chemical softening, microfiltration filtration technology and resin softening technology to reduce the content of calcium and magnesium ions and silicon dioxide in wastewater as much as possible, avoid the pollution blocking of each process, and ensure the normal operation of each process section with zero discharge.

Mineralization treatment system adopts advanced catalytic oxidation technology to mineralize organic matter, which is used to reduce the organic matter content of wastewater solution. The purity of the post-grade crystalline salt is guaranteed.

Nanofiltration salt system uses nanofiltration membrane for salt separation, separating into a salt and a salt, to improve the purity and quality of crystalline salt.

The evaporation crystallization system adopts MVR evaporation crystallization system, and the salt liquid in the wastewater is crystallized.

Technical advantages

  (1) It can not only reduce the salt content of discharged wastewater, but also reduce the amount of salt used in dyeing production, and fully recycle resources.

  (2) Adopt automatic control, the system is stable and reliable, simple operation;

  (3) High purity of crystalline salt;