Biochemical treatment system for coal chemical wastewater

The utility model discloses a coal chemical industry wastewater biochemical treatment system which comprises an anaerobic reactor and a composite reaction tank for degrading CODcr and ammonia nitrogen which are sequentially arranged according to a treatment flow, a reaction zone, a settling zone and a biological membrane zone are arranged in the composite reaction tank, the settling zone is positioned on the outer side of the reaction zone, and the biological membrane zone is positioned on the outer side of the settling zone. The biological membrane area is positioned at the upper part of the reaction area, an inlet of the reaction area is communicated with an outlet of the settling area, and an outlet of the reaction area is communicated with an inlet of the biological membrane area; the utility model discloses a biochemical treatment system for coal chemical wastewater, which integrates a biological fluidized bed and a biological membrane tank into a composite reaction tank, so that the occupied area of the