Since the implementation of the new standard, the COD direct discharge standard limit of pharmaceutical chemical wastewater has been reduced to 50 mg/L. After the traditional process "biochemical +MBR" treatment, the COD is about 100~500 mg/L, which cannot meet the discharge standard. Therefore, advanced treatment is required after MBR process. Conventional advanced treatment processes include advanced oxidation treatment and RO + evaporative crystallization treatment:
● Advanced oxidation treatment: The product water can be discharged directly, but the investment and operation cost is high (investment cost: 100,000-120,000 ¥/t; Operating cost: 4~6 ¥/t).
● RO + evaporative crystallization treatment: The RO product water can be reused, but the RO concentrated water needs to be further treated by evaporation and crystallization process. The investment and operation cost of evaporation and crystallization are high (investment cost: 100,000-110,000 ¥/t; Operating cost: 7~8 ¥/t).
MEY membrane technology process:
Advantages:
● Organic separation membrane PENF can further reduce the COD of pharmaceutical chemical wastewater to 50 mg/L;
● Organic separation membrane PENF does not concentrate the inorganic salt and the concentrated solution can be treated by secondary biochemical treatment;
● Low investment and operation cost (investment cost: 15,000 ~ 20,000 ¥/t; Operating cost: 1.5~2 ¥/t).