A multi-point sludge external reflux enhanced biological nitrogen and phosphorus removal combined process

Abstract

The invention discloses a multi-point sludge external reflux enhanced biological denitrification and phosphorus removal combination process, which belongs to the field of sewage treatment process of urban sewage plants, and divides the interior of biochemical pools into anaerobic pools, anoxic pools, and aerobic pools. pool, anoxic / aerobic transition pool, post-aerobic pool, the water inlet linear proportional distribution weir can directly adjust and distribute water to the anoxic pool, anoxic / aerobic transition pool according to a certain proportion, and the sludge in the secondary sedimentation tank is returned to In the biochemical tank, there is an external return sludge distribution weir outside the secondary settling tank, which is used to distribute the sludge in the secondary settling tank to the anaerobic tank, anoxic tank, aerobic tank, and anoxic / aerobic transition tank in a certain proportion. Add low-temperature-resistant endospore microbial value-added nutrient solution to the proportional distribution weir of the outward return sludge; use the anaerobic tank as a side-flow sludge anaerobic fermentation tank, and mechanically stir the sludge returned from the secondary sedimentation tank to the biochemical tank. Anaerobic fermentation in the side stream sludge anaerobic fermentation tank to increase the carbon source required for the subsequent biochemical process.

Description

technical field [0001] The invention relates to the technical field of sewage treatment technology, and more specifically, relates to a multi-point sludge external reflux enhanced biological denitrification and phosphorus removal combined process. Background technique [0002] With the vigorous promotion of national ecological civilization construction and the continuous improvement of river (lake) water environment quality standards, urban sewage plants are facing increasingly stringent water quality indicators. For example, chemical oxygen demand (CODcr)≤30mg / L (40mg / L), biochemical oxygen demand (BOD)≤5mg / L, suspended solids (SS)≤6mg / L, ammonia nitrogen (NH4+-N)≤1.5mg / L L (3.5mg / L), total nitrogen (TN) ≤ 10mg / L (15mg / L), total phosphorus (TP) ≤ 0.3mg / L (0.5mg / L). [0003] In view of the current situation, there are many phenomena such as rainwater inflow caused by mixed connection of rain and sewage in urban drainage pipes, backflow of river water caused by mixed connect...

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Problems solved by technology

[0005] In the above and traditional activated sludge processes, such as anaerobic / anoxic / aerobic processes and similar traditional processes, it is difficult to guarantee the stability of deep nitrogen and phosphorus removal. Under certain circumstances, it is impossible to achieve deep denitrification in the activated sludge process. Often, in the subsequent three-stage advanced treatment, commercial carbon sources and denitrification filters are used for deep removal. The heavy load relies on advanced treatment to remove nitrogen and phosphorus. It increases the construction cost and operation investment, and also brings a large amount of chemical sludge, which has a negative impact on the subsequent sludge treatment and disposal, and is not conducive to the low-carbon and green development of the sewage plant.

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