Continuous flow sewage hypoxia short distance denitrification treating technique

Abstract

The invention belongs to the technical field of biological sewage treating technique, in particular relates to a continuous flow sewage hypoxia short distance denitrification treating technique. The technique is implemented by a circular flow impelling system, sewage enters into an anaerobic zone through a water inlet pipe, and stays for 50-70min for biological phosphorus release; effluent from the anaerobic zone enters into an anoxic zone and stays for 4-6h with DO value controlled at 0.3-0.7mg / L, and the anoxic zone is provided with a first aeration system to realize anoxia or hypoxia condition to provide conditions for short distance nitrification and denitrification; effluent from the anoxic zone enters into an aerobic zone and stays for 4-6h with DO value controlled at 0.8-1.2mg / L, part of nitrification liquid in the aerobic zone flows back to the anoxic zone with reflux ratio being 0.8-1.5; effluent from the aerobic zone enters into a secondary sedimentation tank for mud-water separation, effluent is discharged at last, part of mud in the secondary sedimentation tank flows back to the anaerobic zone with mud reflux ratio being 0.5-0.8; the aerobic zone is provided with a second aeration system to complete organism degradation and nitrification processes. In the invention, dissolved oxygen, pH and the like are controlled, a hypoxia zone is formed in the anoxic zone, and technologies such as hypoxia short distance nitrification and denitrification, denitrification dephosphorization and the like are utilized, thus realizing the aim of efficiently removing nitrogen and phosphorus from continuous flow activated sludge with energy being saved.

Description

technical field [0001] The invention belongs to the technical field of sewage biological treatment, and in particular relates to a continuous-flow sewage low-oxygen short-range denitrification treatment process. Background technique [0002] With the development of my country's economy, water consumption is increasing, and water pollution is also increasing. Therefore, effective control of water pollution and protection of scarce fresh water resources are directly related to the healthy and rapid development of my country's economy. "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB 18918-2002) has increasingly strict control over the discharge of nitrogen, phosphorus and other nutrient elements. How to improve the denitrification of low C / N ratio sewage in urban sewage biological treatment systems Phosphorus removal efficiency has always been a difficulty. Existing nitrogen and phosphorus removal processes, such as A / A / O, UCT, MUCT, SBR, CASS / CAST, etc.,...

AI Technical Summary

Problems solved by technology

However, there are still few reports on the short-term denitrification of urban sewage by using the continuous flow activated sludge process under low oxygen conditions.

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