Device and method for regulating municipal sewage with low C/N ratio by using water step-feeding oxidation ditch process

Abstract

The invention discloses a device and a method for regulating municipal sewage with low C / N ratio by using a water step-feeding oxidation ditch process. According to the invention, when the C / N ratio of the municipal sewage is in a range of 1 to 3, the municipal sewage directly enters the head end of each anoxic zone of an oxidation ditch reactor in a step-feeding manner, so short-range denitrification anaerobic ammonium oxidation is realized by utilizing a carbon source in raw water in anoxic zones, and full-range nitrification is realized through an aerobic section; when the C / N ratio of themunicipal sewage is larger than 3, an idle sludge fermentation reactor is adopted, and a method of allowing a part of the raw water to enter an organic-matter-removing and phosphorus-removing reactorand then enter the head end of the aerobic zone of the oxidation ditch reactor is employed, so the C / N ratio of obtained sewage is regulated to be in a range of 1 to 3, and excess sludge of the organic-matter-removing and phosphorus-removing reactor can be used for anaerobic methanogenesis; when the C / N ratio of the municipal sewage is less than 1, an idle organic-matter-removing and phosphorus-removing reactor is adopted, and a method of allowing a sludge fermentation liquid to enter the head end of each anoxic zone of the oxidation ditch reactor in sections is employed, so the C / N ratio of obtained sewage is regulated to be in a range of 1 to 3; thus, the method provided by the invention does not need addition of an external carbon source to achieve the effect of autotrophic / heterotrophic denitrification; and through regulation, control and stabilizing of the C / N ratio of an influent, stability is reinforced.

Description

Technical field: [0001] The invention relates to a device and a method for regulating low C / N urban sewage by a staged water inlet oxidation ditch reactor process, belonging to the technical field of low C / N ratio urban sewage treatment. Background technique: [0002] The problem of eutrophication in water bodies is increasing day by day, and the requirements for environmental protection are constantly increasing. The traditional sewage treatment technology of urban sewage plants is nitrification and denitrification process. It cannot meet the needs of denitrification, so additional carbon sources (such as methanol) need to be added, which increases additional costs and sewage treatment costs, and it is difficult to ensure low C / N (usually the C / N ratio is both COD and The mass concentration ratio of ammonia nitrogen) urban sewage treatment efficiency. Therefore, the traditional sewage treatment process of urban sewage plants is in urgent need of innovation. [0003] The d...

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Problems solved by technology

[0004] However, anaerobic ammonium oxidation will produce nitrate nitrogen. Due to the insufficient carbon source in sewage, denitrifying bacteria cannot convert nitrate nitrogen into nitrite nitrogen, which is removed by anaerobic ammonium oxidation or directly by denitrifying bacteria.

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