Sludge side-stream treatment device based on nitrite reinforced sludge fermentation and method thereof

Abstract

A sludge side-stream treatment device based on nitrite reinforced sludge fermentation and a method thereof are applied to a municipal sewage treatment system to reinforce nitrogen removal and sludge in-situ decrement of the system. Part of concentrated sludge in a secondary sedimentation tank enters an anaerobic zone through a return-flow system, and other part of the concentrated sludge is treated by a sludge side treatment system and then flows back to an appropriate zone of the sewage treatment system. Meanwhile, a programmable logic controller (PLC control system) is equipped. By monitoring COD and ammonia nitrogen concentration of influent water, sludge fermentation time and sludge return position of a sludge side return-flow system are controlled, excess sludge return mode is precisely controlled, the influence of influent water quality change fluctuation on the sewage treatment system is reduced, and the nitrogen and phosphorus removal efficiency of sewage is improved. The toxiceffect of nitrite can help reinforce microbial cell lysis to make excess sludge further undergo hydrolytic acidification to produce volatile fatty acids and return an anoxic zone to reinforce nitrogen removal. The device and the method can help save carbon sources, have considerable economic benefits and help reduce subsequent sludge treatment costs.

Description

technical field

[0001] The invention relates to a sludge side flow treatment device and method based on nitrite enhanced sludge fermentation, belonging to the field of urban sewage treatment and resource utilization. Background technique

[0002] In the process of urban sewage treatment, a lot of excess sludge will be produced, and the sludge contains a lot of organic matter. If it is directly discharged into the environment, it will cause secondary pollution to the environment. Therefore, anaerobic digestion is generally used. mud for further processing. That is, under anaerobic conditions, the organic pollutants in the activated sludge are degraded with the help of facultative bacteria and obligate anaerobic bacteria, and the main product of the decomposition is methane-based biogas. The process of digestion and degradation of organic matter under anaerobic conditions can be divided into two main stages, namely the acidic fermentation stage and the alkaline fermentation s...

Examples

Embodiment 1

[0017] The raw water inflow is monitored by the PLC control system (35) and the C / N ratio is 3.6. The raw water is treated by the AAO continuous flow reactor (2) and then enters the sedimentation tank (3). The remaining sludge in the rear sedimentation tank (3) passes through the sludge The concentration of the mud side reflux system (4) removes 40% of the water and then enters the sludge digestion tank (14) for digestion. The digestion time is 1 day, and at the same time, the sludge is digested through the nitrite solution storage tank (13). The nitrite solution is continuously added to the tank (14), and the temperature of the digestion tank is 30°C. After the digestion is completed, the digested sludge rich in organic matter is returned to the anoxic zone I (7) to supplement carbon sources and promote denitrification. Nitrogen action.

Embodiment 2

[0019] The raw water inflow is monitored by the PLC control system (35) and the C / N ratio is 7.8. The raw water is treated by the AAO continuous flow reactor (2) and then enters the sedimentation tank (3). The remaining sludge in the rear sedimentation tank (3) passes through the sludge The concentration of the mud side reflux system (4) removes 30% of the water and then enters the sludge digestion tank (14) for digestion. The digestion time is 5 days. Continuously add nitrite solution to the tank (14), the temperature of the digestion tank is 30°C, the sludge after digestion is relatively stable, and returns to the anaerobic zone I (7) to supplement the activated sludge concentration in the anaerobic zone .

Embodiment 3

[0021] The raw water inflow is monitored by the PLC control system (35) and the C / N ratio is 12.5. The raw water is treated by the AAO continuous flow reactor (2) and then enters the sedimentation tank (3). The remaining sludge in the rear sedimentation tank (3) passes through the sludge After the concentration of the mud side reflux system (4) removes 50% of the water, it enters the sludge digestion tank (14) for digestion, and the digestion time is 10 days. At the same time, the nitrite solution storage tank (13) feeds the sludge digestion tank In (14), nitrite solution is continuously added, the temperature of the digestion tank is 35°C, the sludge after digestion is significantly reduced, and its properties are stable. While supplementing the sludge concentration, the effect of in-situ sludge reduction is enhanced.

technical field

[0001] The invention relates to a sludge side flow treatment device and method based on nitrite enhanced sludge fermentation, belonging to the field of urban sewage treatment and resource utilization. Background technique

[0002] In the process of urban sewage treatment, a lot of excess sludge will be produced, and the sludge contains a lot of organic matter. If it is directly discharged into the environment, it will cause secondary pollution to the environment. Therefore, anaerobic digestion is generally used. mud for further processing. That is, under anaerobic conditions, the organic pollutants in the activated sludge are degraded with the help of facultative bacteria and obligate anaerobic bacteria, and the main product of the decomposition is methane-based biogas. The process of digestion and degradation of organic matter under anaerobic conditions can be divided into two main stages, namely the acidic fermentation stage and the alkaline fermentation s...

Examples

Embodiment 1

[0017] The raw water inflow is monitored by the PLC control system (35) and the C / N ratio is 3.6. The raw water is treated by the AAO continuous flow reactor (2) and then enters the sedimentation tank (3). The remaining sludge in the rear sedimentation tank (3) passes through the sludge The concentration of the mud side reflux system (4) removes 40% of the water and then enters the sludge digestion tank (14) for digestion. The digestion time is 1 day, and at the same time, the sludge is digested through the nitrite solution storage tank (13). The nitrite solution is continuously added to the tank (14), and the temperature of the digestion tank is 30°C. After the digestion is completed, the digested sludge rich in organic matter is returned to the anoxic zone I (7) to supplement carbon sources and promote denitrification. Nitrogen action.

Embodiment 2

[0019] The raw water inflow is monitored by the PLC control system (35) and the C / N ratio is 7.8. The raw water is treated by the AAO continuous flow reactor (2) and then enters the sedimentation tank (3). The remaining sludge in the rear sedimentation tank (3) passes through the sludge The concentration of the mud side reflux system (4) removes 30% of the water and then enters the sludge digestion tank (14) for digestion. The digestion time is 5 days. Continuously add nitrite solution to the tank (14), the temperature of the digestion tank is 30°C, the sludge after digestion is relatively stable, and returns to the anaerobic zone I (7) to supplement the activated sludge concentration in the anaerobic zone .

Embodiment 3

[0021] The raw water inflow is monitored by the PLC control system (35) and the C / N ratio is 12.5. The raw water is treated by the AAO continuous flow reactor (2) and then enters the sedimentation tank (3). The remaining sludge in the rear sedimentation tank (3) passes through the sludge After the concentration of the mud side reflux system (4) removes 50% of the water, it enters the sludge digestion tank (14) for digestion, and the digestion time is 10 days. At the same time, the nitrite solution storage tank (13) feeds the sludge digestion tank In (14), nitrite solution is continuously added, the temperature of the digestion tank is 35°C, the sludge after digestion is significantly reduced, and its properties are stable. While supplementing the sludge concentration, the effect of in-situ sludge reduction is enhanced.

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