Device and method for enhancing reduction of denitrified coupling sludge in urban sewage by using intra-sludge carbon sources by two stages of sequencing batch reactors (SBR)

Abstract

The invention discloses a device and method for enhancing the reduction of denitrified coupling sludge in urban sewage by using intra-sludge carbon sources by two stages of sequencing batch reactors (SBR), belonging to the field of low C / N ratio(mole ratio) urban sewage treatment and excess sludge biochemical treatment. The device disclosed by the invention mainly comprises a SBR1, a SBR2 and a sequencing batch excess sludge fermentation reactor (SBRF). According to the invention, an excess sludge fermentation mixture is taken as a carbon source of SBR1 denitrification, so that biological denitrification is enhanced, and excess sludge is further reduced; deep denitrification is realized by taking excess sludge fermented liquid as a carbon source of SBR2 denitrification, so that discharged water can reach the level-A standard. According to the invention, an anaerobic biological treatment technology and an aerobic biological treatment technology are coupled so as to achieve the purposes of optimally controlling low C / N ratio (mole ratio) urban sewage treatment, saving carbon sources, improving the utilization rate of carbon sources, and reducing the yield of excess sludge. In addition, the device and method disclosed by the invention have the advantages of simple equipment, flexible operation, and the like.

Description

technical field [0001] The invention relates to an optimized control technology of a low C / N ratio (molar ratio) urban sewage intensified denitrification process, belongs to the technical field of urban sewage treatment and residual sludge biochemical treatment, and is a two-stage SBR utilizing sludge internal carbon source to strengthen Device and method for denitrification of urban domestic sewage coupled with sludge reduction. Background technique [0002] my country's 2002 "urban sewage treatment plant pollutant discharge standard" (GB18918-2002) in the first class A standard stipulates that the nitrogen content of the final effluent of the sewage unit is NH 4 + -N<5mg / L, TN<15mg / L. However, it is generally believed that when TN>0.7mg / L, the lake is eutrophic, and when TN>1.3mg / L, the lake is severely eutrophic. With the increasingly stringent discharge standards, more than 95% of the effluent from sewage treatment plants cannot meet the Class A standard, ...

AI Technical Summary

Problems solved by technology

[0003] In the denitrification process of sewage biological treatment, heterotrophic denitrifying bacteria need to use organic matter as a carbon source to reduce oxidized nitrogen, including nitrate nitrogen and nitrite nitrogen. Generally, BOD / TKN> 4 is required. However, most urban sewage treatment in my country At present, there are generally problems of low C / N ratio (molar ratio) of influent water and insufficient carbon source, which makes it difficult to meet the TN standard of effluent water

Existing domestic sewage treatment plants often achieve good water effluent effects by adding external carbon sources, such as methanol, etc., but this not only increases the treatment cost, but also increases the excess sludge production and CO 2 emission

On the other hand, a large amount of sludge is produced in the process of sewage treatment

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