Coking wastewater treatment method

Abstract

The invention relates to a coking wastewater treatment method, which belongs to the technical field of wastewater treatment and is used for solving the problem that the coking wastewater treatment technology leads water quality to be difficult to achieve the standard. The coking wastewater treatment method comprises the steps of tar-ammonia water separation, ammonia distillation, biochemical treatment and the like, and wastewater after the biochemical treatment is treated according to the following steps after improvement: A. sequentially carrying out sand filtration, ultrafiltration and nanofiltration treatment on the wastewater treated biochemically, and carrying out secondary nanofiltration treatment on concentrated solution after the nanofiltration treatment; B. merging filtrate of twotimes of nanofiltration treatment, inputting into the step before the biochemical treatment step as biochemical diluted water or supplementary water of recycling water of a coking plant or being drained to outside; and C. inputting the concentrated solution of the secondary nanofiltration treatment into a tar-ammonia water separation slot in a coking gas purifying system or an ammonia water spraying system of a coke oven and mutually dissolving with tar ammonia water mixed solution. The method increases the membrane treatment based on the existing biochemical treatment for making up for congenital defects of biochemical treatment and is characterized by reasonable process, high purifying rate of wastewater treatment, comprehensive utilization of wastewater and the like.

Description

technical field [0001] The invention relates to a method for treating wastewater, in particular to a method for treating coking wastewater in the field of coal chemical industry, and belongs to the technical field of wastewater treatment. Background technique [0002] The coking wastewater produced in the production process of coal chemical enterprises has complex components, and is a toxic, harmful, and refractory high-concentration organic wastewater. It is very difficult to treat and has always been a technical problem in the field of wastewater treatment at home and abroad. At present, the treatment of coking wastewater is pretreated according to conventional methods, followed by biological treatment, and then the tertiary treatment of chemical treatment. However, indicators such as cyanide, COD and ammonia nitrogen in the treated wastewater are still difficult to meet the standards. In response to this situation, in order to solve the discharge of ammonia nitrogen, COD...

AI Technical Summary

Problems solved by technology

Due to the unstable index of the de-biochemical wastewater, there are some non-biochemical components, and bacterial poisoning often occurs, so that the pass rate of the biochemical water is low, and it is difficult to meet the standard. If the biochemical method is used for advanced treatment, the effect is still not very good, and Large investment, high operating costs

If the influent water is diluted before biochemical treatment and some clean water is added, it will cause an increase in the amount of discharged waste water