Method for treating wastewater with low carbon-to-nitrogen ratio by methanation and denitrification simultaneously

Abstract

The invention discloses a reactor for treating wastewater with low carbon nitrogen ratio by carrying out methanation and denitrification simultaneously. The reactor comprises a barrel and a three-phase separator arranged above the barrel, wherein the three-phase separator comprises two layers of barrels, namely an outer barrel and an inner barrel; the inner barrel is arranged inside the outer barrel; openings are formed in the bottoms of the outer barrel and the inner barrel; the bottom of the outer barrel is divided into an upper section and a lower section which are connected; the upper section of the bottom of the outer barrel shrinks inwards; the lower section of the bottom of the outer barrel expands outwards and forms a first-grade baffle plate; the lower part of the inner barrel expands outwards to form a second-stage baffle plate; the upper section and the lower section of the outer barrel extend into a cavity of the barrel; the inside of the three-phase separator is divided into four areas, namely an air chamber area, a gas slow release area, a settling area and a reflux area; a peripheral effluent weir is arranged into a circle on the outer barrel and at the upper position of the reflux area. The invention also discloses a wastewater treatment method, denitrification and methanogenesis can be simultaneously implemented in a single reactor by controlling the C / N values in different stages. The reactor and the method have the advantages that organics and nitrogen in the wastewater can be deeply removed simultaneously, the removal rate is high, and an energy source methane can be produced.

Description

technical field [0001] The invention relates to the technical field of industrial wastewater treatment, in particular to a reactor and a method for treating wastewater with a low carbon-to-nitrogen ratio by methanation and denitrification simultaneously. The reactor can simultaneously realize anaerobic methanation and denitrification. Background technique [0002] UASB (Up-flow Anaerobic Sludge Bed / Blanket, English abbreviation for Up-flow Anaerobic Sludge Bed / Blanket, hereinafter referred to as UASB) consists of three parts: sludge reaction zone, gas-liquid-solid three-phase separator (including sedimentation zone) and gas chamber. . A large amount of anaerobic sludge remains in the bottom reaction zone, and sludge with good sedimentation and coagulation properties forms a sludge bed in the lower part. The wastewater to be treated flows from the bottom of the anaerobic sludge bed and is mixed with the sludge in the sludge bed, and the microorganisms in the sludge decompos...

AI Technical Summary

Problems solved by technology

Traditional theory holds that NO 3 - The presence of -N will lead to competition between denitrifiers and methanogens, thereby inhibiting methanation

The inhibitory effect of denitrifying bacteria on methanogens is manifested in three aspects: ①The denitrifying bacteria group has an advantage in the competition for carbon source substrates; ②The denitrification process leads to an increase in the redox potential in the anaerobic system, which is not conducive to The growth of methanogenic bacteria; ③The intermediate products of denitrification reaction have a toxic effect on the methanogenic bacteria

[0005] Therefore, the existing UASB has the disadvantage that organic matter and nitrogen in wastewater cannot be removed at the same time, that is, denitrification and methanation reactions cannot occur simultaneously in a single UASB reactor.

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