'Main-auxiliary' activated sludge method for coupling deodorization and strengthening nitrogen and phosphorus removal

Abstract

The invention relates to a 'main-auxiliary' activated sludge method for coupling deodorization and strengthening nitrogen and phosphorus removal. A main line adopts traditional activated sludge and adeformation process thereof, and in an 'auxiliary' line, a sludge micro-screen filter, a side-flow sludge biological culture tank (S2HBR) filled with a strain culture tank (SBIO-A) and a side-flow activated sludge anaerobic hydrolysis tank (S2ASH) reactor are arranged in an activated sludge return line; an auxiliary line reaction tank S2HBR and S2ASH tank can be connected in parallel or in series.The method can directionally enrich, and significantly improve and optimize a flora structure of the activated sludge, 'main-auxiliary' reactor combination achieves the directed cultivation of specific microorganisms through a side-flow reactor on the 'auxiliary' line and conducts functional microbial inoculation on a main biochemical system on the 'main line', and the 'main-auxiliary' reactor configuration can achieve deep denitrification and dephosphorization of the biochemical system, and significantly improve the deodorization effect of the whole process, while saving commercial carbon sources and achieving activated sludge In situ process reduction.

Description

technical field [0001] The invention belongs to the field of sewage treatment and water environment treatment, and in particular relates to a "main-auxiliary" activated sludge method that couples the whole process of deodorization and strengthens the functions of nitrogen and phosphorus removal. Background technique [0002] At present, China's water environment problems are frequent, surface water eutrophication is serious, and the water quality of some water areas even loses the function of drinking water source. important long-term tasks. At the same time, due to historical reasons, many urban sewage plants are built in urban areas. The process of sewage collection and treatment releases a large amount of volatile odorous gases (such as hydrogen sulfide, ammonia, etc.), which seriously interferes and affects the ambient air quality of surrounding cities. The avoidance effect becomes more prominent. Stable water quality compliance and odor control are common problems fac...

AI Technical Summary

Problems solved by technology

[0003] At the same time, many areas of our country suffer from severe shortage of carbon sources for sewage plants. Existing conventional treatment processes, such as deformation processes of various activated sludge methods, AAO and its variant processes, oxidation ditch, MBR, SBR and Its various variant processes mainly rely on the traditional phosphorus removal bacteria Accumulibacter to achieve EBPR (Enhanced Biological Phosphorus Removal), while Accumulibacter can only rely on the ingestion of VFA in the influent, and there is also substrate competition between PAO and GAO; in addition, the reflux of nitrate and DO Interference with the anaerobic zone makes it difficult to control the ORP below -150mv in the anaerobic zone, which is not an ideal anaerobic environment for biological phosphorus removal. Many of the above factors lead to unstable biological phosphorus removal effects of traditional mainstream treatment processes

In addition, the high pollution load caused by the high ammonia nitrogen reflux of the sludge dewatering liquid in the sludge treatment section, the low water temperature season and other factors lead to insufficient nitrification capacity and the ammonia nitrogen in the effluent does not meet the standard. The above factors make it difficult for the traditional process to remove nitrogen and phosphorus. For further improvement, standard upgrading often has to choose to transform the original aeration tank into the IFAS process, or add a third-level biochemical treatment unit (such as BAF, deep-bed denitrification filter), which greatly increases the project investment. At the same time, it also increases the operating cost during the operation period, and the greenhouse gases released by the environment also increase exponentially with the prolongation of the process. The lengthy upgrading and transformation process is generally unsustainable

[0004] After more than a hundred years of development, the activated sludge process is still the most economical and effective method for sewage treatment. However, the traditional mainstream activated sludge process is vulnerable to external disturbances (water quantity, water quality, and water temperature changes). From the perspective of the control of the bacterial flora structure, because the traditional mainstream activated sludge process only has the activated sludge process on the "main line", although anaerobic, anoxic and aerobic environments are set, the above environments are affected by various factors (influent water quality water fluctuations, internal backflow and external backflow), and the removal of different pollutants must be taken into account, but the ecological niches of different microorganisms are very different, so it is difficult to take into account the habitat conditions of different functional flora under the process control conditions, and it is difficult to realize the removal of active pollutants. The optimization and regulation of the structure of the mud flora makes it more difficult to achieve directional transformation and control

[0005] In response to the above problems, the current technical route solutions often use "multiple methods" and "separate solutions". The process is becoming more and more complicated, but systematic and collaborative consideration is not achieved, and nutrients are often solved through the superposition of lengthy process routes. However, the deodorization problem is still not resolved, and it is still necessary to increase the deodorization measures along the whole process along with the extension of the sewage treatment process, resulting in high investment and operating costs for the deodorization system.

Some deodorization technologies commonly used at present have been investigated. The collection method deodorization equipment and operating costs are high, and it needs to be covered to collect odors to form a closed space, which will cause great corrosion to the equipment; other types of existing biological deodorization technologies, such as rotting Soil deodorization or soil microbial deodorization technology, the microbial culture medium used is relatively single composition such as humus, or clay and cement cement, lime pressing, or other biofilm carriers such as volcanic rock, etc. fired or pressed The processing process of the above-mentioned matrix or carrier makes the matrix denatured and the biological activity of the components is unfriendly. The most important thing is that it is difficult to directional and stably cultivate deodorant microorganisms such as Bacillus, and even destroy the activity of microorganisms. Therefore, many deodorant microorganisms currently in operation in China Smelly project, the effect is unstable and extremely unsatisfactory

[0006] In addition, some existing deodorization methods of activated sludge in the whole process, such as placing the culture tank in the main aeration tank, the operating MLSS is low (2500-4500mg / L), and the MLSS in the main aeration tank is low, which is not conducive to The enrichment of microorganisms in the culture tank; in addition, in order to strengthen the removal of pollutants such as COD, N, and P in the aeration tank, continuous aeration is often used, and DO is too high, and there is even excessive aeration, which is not conducive to the enrichment of deodorizing microorganisms It is also not conducive to sludge reduction, because some deodorizing microorganisms prefer a facultative state, or an anaerobic / anoxic / aerobic alternate environment, which is more conducive to stimulating the biochemical activity of these special flora

In addition, the cultivation tank is in the main biological tank, and the activated sludge mixture in the main biological tank is mixed with impurities such as sand and fibers with a high content, which is very easy to block the filling layer of the tank.

[0007] The technical scheme disclosed in the document "Decontamination Efficiency and Deodorization Effect of Humic Soil Activated Sludge Technology (China Water and Drainage, 2007, 23 (14))" focuses on theoretical research, and only gives the humus soil activated sludge process. The introduction of the basic principles and general process characteristics, and in the process mentioned in the literature, the humus soil cultivation tank and the main aeration tank are jointly built, the return flow of the humus soil cultivation tank is only 3%-10%, and the cultivation tank is Continuous aeration, the composite catalytic filler in the culture tank does not embed functional bacteria, and the mixed solution with DO in the culture tank flows directly to the anaerobic section of the biological tank, which destroys the biological phosphorus release effect of the anaerobic tank. The problem has affected the process effect of the actual project is not ideal, and even there is a contradiction between deodorization and phosphorus removal

At the same time, since the return sludge contains more inorganic components such as sand and fiber impurities, these impurities will greatly reduce the microbial activity after entering the culture tank, block the culture tank, and even cause the culture tank to fail to operate normally

In addition, this kind of simple humus activated sludge deodorization soil microorganisms are slowly cultivated in the biochemical system, and it takes 2-6 months or even longer to start the deodorization effect slowly, which affects the operation and environmental protection of the sewage plant acceptance

Images