Device and method for recycling nitrogen in sewage treatment plant

Abstract

The invention discloses a device and a method for recycling nitrogen in a sewage treatment plant, the device comprises an anaerobic digester and an integrated biofilm reactor, the anaerobic digester is respectively communicated with a residual sludge water inlet pipe, a sludge digestion liquid pipeline and a methane collecting device, the sludge digestion liquid pipeline is communicated with the integrated biofilm reactor, and the integrated biofilm reactor is divided into an area A and an area B; each of the area A and the area B is respectively provided with a gas-liquid separation membranewhicha nitrosation biofilm is attached to andgrows on and a modified gas-liquid separation membrane which a denitrification biofilm is attached to and grows on , andthe area A and the area B are respectively communicated with an air pump and an N2O a collection device; and the area A converts ammonia nitrogen in the sludge digestion liquid into nitrite nitrogen, and the area B converts nitrite into N2O and collects the N2O, so that the conversion rate of the N2O is higher than 90%. And the generated N2O and the anaerobic digester product methane are subjected to coupled combustion, so that thecombustion heat value can be increased by 37%, thereby implementing the energy utilization of the nitrogen in the sewage treatment plant.

Description

technical field [0001] The invention belongs to the technical field of environment and resource recovery, and mainly relates to a nitrogen energy conversion device and method for a sewage treatment plant. Background technique [0002] Excess sludge is a by-product of sewage biological treatment. Large-scale urban sewage treatment plants often use anaerobic digestion for excess sludge, and collect methane from the digested product, and reuse energy through power generation. This process also produces a digestate containing high concentrations of ammonia nitrogen, which is returned to the water inlet by the sewage plant and treated by the traditional nitrification-denitrification denitrification process, which repeatedly consumes energy. [0003] In recent years, studies have found that the N produced in the process of biological denitrification 2 O is a potential renewable energy source, for example, when it is combusted with methane instead of oxygen, it can increase the ca...

AI Technical Summary

Problems solved by technology

[0004] The energy utilization of nitrogen in the process of sewage treatment has attracted people's attention increasingly, for the repeated consumption of energy in the treatment of sludge digestion liquid in urban sewage treatment plants, and the nitrogen removal process in the traditional denitrification process. 2 The problem of low O release and difficult recovery, the purpose of the present invention is to provide a method to realize the efficient conversion of high-concentration ammonia nitrogen in the digestive juice into N 2 The device and method for O and recovery, through coupled combustion with the digested product methane, so as to realize the energy utilization of nitrogen in sewage treatment plants

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