Method for treating and recycling coal tar processing wastewater

The invention relates to the technical field of coal tar processing wastewater treatment and recycle, in particular to a method for treating and recycling coal tar processing wastewater. The method is characterized by being a combined technological method including pretreatment, biological treatment and post-treatment, and comprises the processing steps that: 1) a pretreatment device comprises an oil separation tank, a gas flotation tank, and a hydrolysis and acidification regulation tank connected in sequence; 2) a biochemical treatment device comprises a short-range nitrification tank, an anaerobic ammonium oxidation tank, and an aerobic biological carbon tank connected in sequence; and 3) for the water quality of the discharged water after post-treatment, the COD is lower than 70mg/L, SS is lower than 1 mg/L, and chrominance is less than 15 times. Compared with the prior art, the method of the invention has the beneficial effects that: the biochemical property of the waste water is enhanced by finishing hydrolytic acidification in the regulation tank; and the biological treatment is strengthened through an effective combination of the short-range nitrification tank, the anaerobic ammonium oxidation tank, and the aerobic biological carbon tank; the problem that the coal tar processing wastewater is difficult to reach the standards is solved, and the purpose of recycling the wastewater is achieved.