Short-cut nitrification and denitrification treatment process for coking wastewater

Abstract

The invention discloses a coking wastewater short-cut nitrification and denitrification treatment technology, and solves the problem that an existing technology is long in technological process, large in equipment occupation space, large in investment, high in running cost and the like. The technical scheme is as follows: mixing coking wastewater with sludge to form mixed liquid, enabling the mixed liquid to be subjected to at least one cycle of high dissolved oxygen aeration treatment, a low dissolved oxygen reaction, a hypoxia reaction, and discharging the mixed liquid after the high dissolved oxygen aeration treatment, wherein the coking wastewater retains for 8 to 12h in the phase of high dissolved oxygen aeration treatment, the dissolved oxygen concentration of the mixed liquid in the step is controlled to be DO being larger than 4mg / L; the coking wastewater retains for 2 to 3h in the phase of low dissolved oxygen reaction, and the dissolved oxygen concentration of the mixed liquid in the step is controlled to be DO being less than 2mg / L; the coking wastewater retains for 7 to 9h in the phase of hypoxia reaction. The technology provided by the invention is simple, the occupied space is less and the investment and running cost are low.

Description

technical field [0001] The invention relates to the field of coking wastewater treatment, in particular to a short-range nitrification and denitrification treatment process for coking wastewater. Background technique [0002] Coking wastewater is one of the most difficult industrial wastewater to treat. With the improvement of national environmental protection requirements, its biological treatment has developed from the initial simple activated sludge treatment process to the current multi-stage aerobic-anoxic / anaerobic treatment. craft. With the extension of the coking wastewater biological treatment process route, the residence time of coking wastewater has been extended from more than 20 hours in the original simple activated sludge method to more than 80 hours in the current treatment process, and some even nearly 200 hours. Most of these treatment technologies focus on the removal of COD and ammonia nitrogen in coking wastewater. [0003] With the prominent exposure ...

AI Technical Summary

Problems solved by technology

[0008] (1) Existing coking wastewater generally adopts multi-stage A-O biological treatment technology, which has long process flow, large facility area and large investment;

[0009] (2) The existing coking wastewater biological treatment system has a poor removal effect on total nitrogen, and carbon sources need to be supplemented in the denitrification unit, resulting in high operating costs;

[0010] (3) For coking wastewater in coking areas with low COD and low C / N, the existing treatment technology cannot be started and operated normally due to the constraints of insufficient carbon sources;

[0011] (4) The existing coking wastewater biological treatment system has a large amount of sludge and a large consumption of alkali sources;

[0012] (5) The existing coking wastewater biological treatment facilities are poorly sealed, the water surface area exposed to the atmospheric environment is large, the VOC volatilization of the water body is large, and the degree of air pollution is high;

[0013] ⑹The existing coking wastewater biological treatment technology has a long process route and a long residence time of coking wastewater, which is inconvenient to operate, control and manage;

[0014] ⑺The existing coking wastewater biological treatment facilities have a large maintenance workload and high maintenance costs;

[0015] ⑻ The existing coking wastewater biological treatment facilities have long pipelines and many contacts, and the phenomena of running, popping, dripping and leaking are serious

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