Industrial sewage deep denitrifying and recycling process

Abstract

The invention relates to an industrial sewage deep denitrifying and recycling process. Aiming at the problems of the existing prepositioned denitrification or synchronous denitrification denitrifying process that the denitrification is not complete and total nitrogen content of output water is higher, the invention provides an O / A / O (Oxic / Anoxic / Oxic) process and a first-grade aerobic tank and ananaerobic tank are respectively controlled to optimal conditions needed by nitrification and denitrification, so that nitrification, carbonization and denitrification processes can be completely finished; a residual carbon source of denitrification is decomposed in a second-grade aerobic tank; and the tank is internally provided with an ultra-filtration membrane to replace a sedimentation basin. The industrial sewage deep denitrifying and recycling process disclosed by the invention has the characteristics of high total nitrogen content and COD (Chemical Oxygen Demand) removing rate, simple flow and convenience for controlling, is applicable to modifying the existing sewage treatment system with a total nitrogen index which does not reach to the standard, or deep denitrification treatmentof industrial sewage which has high total nitrogen and insufficient carbon source, and is difficult to biologically degrade; and the output water can be used as a water resource of supplement water of circulating cooling water, and supplement water of a boiler, and has other usages.

Description

technical field [0001] The invention relates to the field of environmental protection sewage treatment, in particular to a process for deep denitrification and reuse of industrial sewage. Background technique [0002] Nitrogen exists in domestic sewage and most industrial sewage. The nitrogen produced by these human activities is the main cause of eutrophication in rivers and water bodies. Increasing the total nitrogen control index has become an important content of the revision of national and local sewage discharge standards. For example, the primary / secondary total nitrogen index of "Pollutant Discharge Standards for Urban Sewage Treatment Plants" GB18918-2002 is 15 / 20mg / L, "Shanghai The primary / secondary total nitrogen index of the municipal sewage comprehensive discharge standard DB31 / 199-2009 is 25 / 35mg / L. [0003] The forms of nitrogen in sewage are divided into inorganic nitrogen and organic nitrogen, and inorganic nitrogen includes ammonia nitrogen and nitrate nit...

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Problems solved by technology

[0008] The purpose of the present invention is to provide a deep denitrification and reuse process of industrial sewage, which mainly solves the problems of incomplete denitrification and high total nitrogen in the effluent in the existing pre-denitrification or synchronous denitrification denitrification process, and at the same time provides a comprehensive It provides a technical solution for the transformation of the existing sewage treatment system whose nitrogen index is not up to the standard, or the transformation of the industrial sewage system with high total nitrogen, insufficient carbon source and difficult biodegradation. It is especially suitable for the existing sewage treatment system whose total nitrogen index is not up to the standard Transformation, or deep denitrification treatment of industrial wastewater with high total nitrogen, insufficient carbon source and difficult biodegradation, the effluent can be reused as circulating cooling water replenishment water, water source for boiler replenishment water and other purposes

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