A deep denitrification method for low-carbon source sewage with two stages ao in series

Abstract

The invention discloses a deep denitrification biological treatment method for low-carbon source high-nitrogen-containing sewage with two stages of AO connected in series. The main process of biological treatment of part of the sewage in the process flow is: influent → anaerobic tank → first anoxic tank → first sedimentation tank → second anoxic tank → second aerobic tank → second sedimentation tank → effluent, the first The sludge in a sedimentation tank is subjected to aerobic nitrification in the process of returning to the first anoxic tank, and the nitrification solution in the second aerobic tank is returned to the second anoxic tank. This method essentially sets the anoxic-aerobic (AN / O) biological denitrification system as a two-stage series connection, but adopts a relatively special process flow arrangement, and the first stage of the system can be optionally dosed with adsorbents. The method of the invention is suitable for the treatment of industrial wastewater or domestic sewage with less carbon sources (low carbon-nitrogen ratio) and high Kjelstein nitrogen concentration.

Description

technical field [0001] The invention belongs to the technical field of water environment protection, and is a method for fully utilizing carbon sources by oxidizing and nitrifying return sludge, thereby achieving the purpose of high-efficiency denitrification. The invention is suitable for industries with high nitrogen concentration and low carbon-nitrogen ratio Wastewater or domestic sewage treatment methods. Background technique [0002] In the process of urban sewage treatment, the removal of total nitrogen and total phosphorus needs to meet a certain amount of organic matter respectively. Because the concentration of organic matter in the influent of urban sewage plants is generally low, it is difficult to remove nitrogen and phosphorus in urban sewage. Urban sewage plants usually focus on the removal of total nitrogen, and the removal of total phosphorus can be completed by adding chemicals to a certain extent. Therefore, how to improve the removal rate of total nitroge...

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Problems solved by technology

The external carbon source is simple, but the cost is high, and the sewage plant cannot bear it; the strategy of changing the water intake is currently often adopting measures such as step-by-step water intake (multi-point water intake), but the process is more complicated, there are many structures, and the operating cost is significantly increased; anaerobic Ammonium oxidation technology can fundamentally solve the problem of insufficient carbon sources, but the conditions required for anaerobic ammonium oxidation are very harsh, generally suitable for industrial wastewater with high ammonia nitrogen, and it is difficult to apply to the field of urban sewage treatment. Currently, the anaerobic ammonium oxidation method is based on The developed denitrification process is not yet a mature process applied to urban sewage treatment; the multi-stage AO series process is similar to the step-by-step water inflow process. Multiple anoxic pools and aerobic pools are connected in series, and the water intake is divided into multiple channels. The process has good denitrification effect, but the denitrification rate of this process depends on the number of series-connected stages of AO. The more the series-connected stages, the better the denitrification effect. Too many stages will inevitably lead to a lot of process structures. , a significant increase in operating costs

[0003] For wastewater with high concentration of Kjeldahl nitrogen and insufficient carbon-to-nitrogen ratio, if the traditional treatment process and method are still used to treat this type of wastewater, the total nitrogen removal rate will not be high, making it very difficult to meet the new discharge standards

In order to meet the emission standards, advanced treatment technology is required. Generally, the process is complicated, there are many equipments, the consumption of energy and chemicals is large, the operating cost is high, and the operation is unstable, which is unbearable for enterprises.

This makes it difficult for many coking, petrochemical or certain pharmaceutical enterprises to meet the new standard discharge under the existing economic and technical conditions. Technical solutions

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