Method for biochemical treatment and standard discharge of sewage of coal chemical industry

Abstract

The invention provides a method for biochemical treatment and standard discharge of sewage of coal chemical industry. The method comprises the steps of BDO (1,4-butanediol) pretreatment and main biochemical treatment, wherein the BDO pretreatment is performed sequentially through a coagulative precipitation tank, an anaerobic tank and a SBR (sequencing batch reactor) tank; the main biochemical treatment is performed sequentially through an aerobic carrier fluidized bed reactor, a pre-denitrification tank, an aerobic activated sludge tank and a secondary sedimentation tank; and a mixed liquor which flows out of the aerobic activated sludge tank partially or entirely flows back into the pre-denitrification tank. The whole process is high in volume loading and impact resistance, and operates safely and stably. The whole biochemical system has high impact resistance; and the treatment effect is slightly affected by the change of the temperature. The whole system has a compact structure and is small in floor area. After high-concentration BDO sewage is pretreated, chemical oxygen demand (COD) of an effluent can be stably maintained to be less than 500mg / L, so that the main biochemical treatment can be easily performed; and after the sewage of the coal chemical industry is subjected to main biochemical treatment, the COD of an effluent can be stably maintained to be less than 50mg / L, so that the national first-class discharge standard is met, and the investment and operation cost is saved.

Description

technical field [0001] The invention belongs to sewage treatment technology, in particular to a biochemical combination treatment method for coal chemical sewage. Background technique [0002] In order to solve the contradiction between my country's resource development and reserves and economic development, and reduce dependence on crude oil, the coal chemical industry has been actively developed in my country's major coal-producing areas in recent years. Coal chemical industry is a high-pollution and high-energy-consuming industry, and the surrounding environment bears huge potential threats. In order to make the industry embark on the road of sustainable development, in 2006 the National Development and Reform Commission and the State Environmental Protection Administration issued "On Strengthening the Construction of Coal Chemical Projects" Management and Promotion of the Healthy Development of the Industry", encourages the use of water-saving processes, and vigorously p...

AI Technical Summary

Problems solved by technology

[0005] The above methods have their own advantages and disadvantages. For example, the pure biochemical method contains a certain amount of refractory organic matter in the effluent, and the COD value is too high, which cannot fully meet the discharge standard; although the adsorption method can remove CODcr well, there are regeneration of the adsorbent and secondary pollution. The problem of secondary pollution; although the catalytic oxidation method can degrade organic substances that are difficult to biodegrade, there are problems such as high operating costs in actual industrial applications; the combined anaerobic-aerobic treatment of coal chemical wastewater can obtain ideal treatment effects, operation management and cost. Relatively low, but when the concentration of incoming water is high and contains a lot of refractory organic matter, it is difficult to reach the standard in a stable way, so it needs to be used in conjunction with catalytic oxidation, coagulation and sedimentation, etc., which increases the operating cost

[0006] To sum up, when the above-mentioned process treats coal chemical wastewater, it may be difficult to meet the national first-level discharge standard, or the operating cost is high, or secondary pollution is generated, or the operation is unstable, and it is difficult to meet the requirements of coal chemical wastewater treatment, which requires research. A Coal Chemical Wastewater Treatment Process with Low Operating Cost, Stable and Reliable, and No Secondary Pollution

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