Coking wastewater treatment method

Abstract

A coking wastewater treatment method is as follows: coking wastewater pretreated by a gravity degreasing tank and an air flotation degreasing tank is treated by collaborative Fenton oxidation and coagulation precipitation by use of a sequencing batch membrane bioreactor, metallurgical slag with 1 / 8 to 1 / 6 of effective volume of the reactor are added into the sequencing batch membrane bioreactor, metallurgical slag accounted for 0.3%-0.8% of the metallurgical slag amount is supplemented into the sequencing batch membrane bioreactor every 10-15 days, iron mud precipitate produced by Fenton reaction is refluxed into the sequencing batch membrane bioreactor every 5-7 days, and the reflux amount is 6% to 8% of the reactor sludge amount; the sequencing batch membrane bioreactor is anoxically stirred for 7-8h in every cycle, aerobic aeration time is 15-17h, and the residence time is 70-73h. According to the method, by use of the flocculation effect of iron hydroxide floc, wastewater treatment effect is strengthened, alkalinity consumed in nitrification process can be mitigated, and the iron mud precipitate produced by the reaction can be recycled, meanwhile by taking advantage of adsorption precipitation performance of the metallurgical slag, purposes of improvement of wastewater treatment effect and reduction of wastewater treatment costs can be realized.

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 ...

AI Technical Summary

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.

Images