Technology for sodium sulfate wastewater treatment and salt purification recycling

The invention belongs to the technical field of wastewater treatment, and discloses a technology for sodium sulfate wastewater treatment and salt purification recycling. The technology is mainly technically characterized in that pH is regulated to 9-10 through addition of sodium hydroxide, PAM (polyacrylamide) is added simultaneously, and zinc and nickel are precipitated and dehydrated for recycling; treated water enters a second-stage efficient precipitation separator, pH is regulated to 10-12 through addition of sodium hydroxide, PAM is added simultaneously, and copper, cobalt and manganese ions are precipitated and dehydrated for recycling; finally, sodium sulfate wastewater after impurity removal is frozen, the temperature is controlled in a range from 2 DEG C to3 DEG C, and a sodium sulfate aqueous solution is changed into solid for recycling. According to the technology, the equipment investment is low, the operation expense is low, salt can be totally separated for recycling, outer drainage and hazardous waste are avoided, and zero release is realized; energy conservation and environment protection are facilitated; and the technology has higher economic and social benefits.