Surplus sludge fermenting and coupling denitrification device and method in condition of low dissolved oxygen

Abstract

The invention relates to a surplus sludge fermenting and coupling denitrification device and method in a condition of low dissolved oxygen, and belongs to the field of biological treatment of sewage sludge. The device comprises a raw water pond, a sludge storage pond, a fermenting and coupling denitrification main reactor, a drainage pond, an air compressor and a sludge discharge pond. The main reactor is provided with a stirrer, a temperature control device and a gas flowmeter. The method comprises the following steps of: putting grafting sludge discharged from a sludge digestion system and surplus sludge in the main reactor; starting the temperature control device and the air compressor connected with the main reactor; adjusting the flow of the gas flowmeter according to concentration of dissolved oxygen in the main reactor; injecting a nitrifying liquid to the main reactor; and performing reaction on the sludge and water mixture in the main reactor. According to the invention, the purpose of development of carbon source of surplus sludge, enhancement of nitrifying liquid denitrification and reduction of sludge in the same reactor is realized, and meanwhile, ammonia nitrogen released in the fermenting process of surplus sludge can be removed by nitrification and denitrification in the condition of continuous low dissolved oxygen, so that the problem of high ammonia nitrogen concentration in effluent of the fermenting reactor is solved.

Description

technical field [0001] The invention relates to a sludge and sewage biological treatment technology, in particular to a system and a method for treating surplus sludge with simultaneous nitrification and denitrification. Background technique [0002] Activated sludge method is currently the most widely used sewage biological treatment technology in the world, but it has always had a big disadvantage, that is, it will generate a large amount of excess sludge. How to realize the reduction, stabilization and resource utilization of sludge , Harmlessness is a major problem faced by urban sewage treatment plants; after the promulgation of new sewage discharge standards, the requirements for effluent TN have been increased. Therefore, most urban sewage treatment plants in China are facing the problem of upgrading and transformation, but they must In order to meet the TN emission standards in the effluent, we are faced with the problem of insufficient raw water carbon sources. Whe...

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Problems solved by technology

[0003] However, existing studies generally focus on the development of carbon sources in excess sludge, while ignoring the utilization of internal carbon sources, and the development and utilization of internal carbon sources are carried out separately

This has the following problems: (1) Before the developed internal carbon source is used in the denitrification and phosphorus removal process of the sewage treatment plant, it needs to be washed, separated and transported by pipeline, which is poor in operability and increases the cost of infrastructure and operation; (2) ) After the fermentation of the remaining sludge, the concentration of ammonia nitrogen in the fermentation liquid is very high, and the fermentation liquid is used as a carbon source to supplement the influent of the sewage treatment plant, which will increase the nitrogen load of the influent

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