A kind of treatment method of coking wastewater

Abstract

A treatment method for coking wastewater. Coking wastewater pretreated by gravity degreasing tanks and air flotation degreasing tanks is treated by using sequencing batch membrane bioreactors in cooperation with Fenton oxidation and coagulation sedimentation. Add metallurgical waste slag of 1 / 8 to 1 / 6 of the effective volume of the reactor into the reactor, and add metallurgical slag accounting for 0.3% to 0.8% of the amount of metallurgical slag to the reactor every 10 to 15 days; The iron sludge produced by the Fenton reaction is refluxed once, and the reflux volume is 6% to 8% of the sludge volume in the reactor; the operation of the sequencing batch membrane bioreactor is anoxic stirring for 7 to 8 hours per cycle, and aerobic aeration for 15 to 8 hours. 17h, the residence time is 70-73h. The invention utilizes the flocculation effect of the ferric hydroxide floc to strengthen the waste water treatment effect, alleviate the alkalinity consumed in the nitrification process, and recycle the iron sludge precipitation produced by the reaction. At the same time, the adsorption and precipitation performance of metallurgical slag is used to achieve the purpose of improving the effect of wastewater treatment and reducing the cost of wastewater treatment.

Description

technical field [0001] The invention belongs to the field of industrial wastewater treatment, and in particular relates to a method for intensively treating coking wastewater by utilizing metallurgical waste residue and iron sludge precipitation produced by Fenton reaction (Fenton reaction). Background technique [0002] Coking wastewater is wastewater produced in the process of coal coke, gas purification and chemical product refining. heterocyclic and polycyclic aromatic compounds (PAHs). Because cyanide, polycyclic aromatic hydrocarbons and heterocyclic compounds are difficult to biodegrade, and high concentration of ammonia nitrogen has a strong inhibitory effect on microbial activity, resulting in poor biodegradability of wastewater, coking wastewater has always been recognized as the most difficult industry to treat. One of the wastewater. With the rapid development of my country's iron and steel industry and the continuous expansion of coke production capacity, the ...

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Problems solved by technology

Although this method is equipped with a micro-electrolysis process, it can decompose some refractory organic matter, but because it does not meet the degradation conditions of all organic matter, the effluent index can only meet the second-level discharge standard in the comprehensive sewage discharge standard, and the treatment effect is not ideal.

[0009] To sum up, due to the complex and changeable composition of coking wastewater, which contains a variety of long-chain and cyclic organic substances that are difficult to degrade, the biodegradability of wastewater is poor, and it is difficult to achieve the desired effect by only one treatment method. Combined with biochemical technology to treat coking wastewater, but there are unsatisfactory treatment effects, complex process flow and high operating costs in the treatment, and the respective advantages have not been brought into play, making it difficult for the treated water to meet the current discharge standards.

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