Research on the application of low temperature heat pump evaporation-biochemistry-RO in wastewater reuse

A combined process of low-temperature heat pump evaporation,biochemistry, and reverse osmosis(RO) was used to deeply treat and reuse the cleaning wastewater from a certain enterprise. Firstly,a low-temperature evaporator was used to remove most of the organic matter and salt, followed by a biochemical system to remove the organic matter and ammonia nitrogen,and finally the RO system was used to remove the remaining organic matter and salt. The operation results indicated that the effluent quality could meet the water quality requirements of the enterprise's production process. The specific water quality indicators were COD≤10 mg/L, ammonia nitrogen≤1 mg/L, SS≤1 mg/L, LAS≤1 mg/L, and conductivity ≤60 μS/cm, pH=6-9. The project was implemented with significant economic benefits. An economic and technical comparison was conducted between low-temperature heat pump evaporation and other traditional evaporation technologies.