2. Research progress of sludge composting in China.
In China, Indian and other eastern countries, primitive composting methods appeared a long time ago, and working people have always attached importance to improving soil through composting. However, compared with foreign countries, the research on agricultural utilization of municipal sludge in China is far from theoretical research and practice. In the early 1960s, the experiment of sludge natural ventilation composting in Beijing Gaobeidian Sewage Treatment Plant was successful, and the dominant position of aerobic fermentation composting process was determined. At present, there are less than14 sewage treatment facilities with sludge stabilization treatment facilities in China, and less than110 with relatively complete treatment technology and supporting equipment.
Beijing Research Institute of Environmental Protection has built an organic compound fertilizer production line with an annual output of 3,000 tons. The self-developed high-efficiency drum-type sludge composting equipment was used for dynamic rapid fermentation, which reduced the moisture content of sludge while harmless treatment, and solved the key pretreatment problems in fertilizer production. This is an efficient sludge composting equipment.
In order to achieve the goal of economic, practical, efficient and low-consumption, it is necessary to carry out more in-depth and systematic experimental research on sludge composting process, so that municipal sewage sludge composting has better economic, environmental and social benefits. In the future, we should strengthen the research in the following aspects: developing new conditioners, paying attention to the control of odor during sludge composting, establishing evaluation standards for sludge composting process and products, deeply studying and separating dominant populations of rapid aerobic composting, shortening composting time and improving composting efficiency. The proportion of sludge used in agriculture in China is less than 10%, and sludge composting has great development prospects and space.
3. Technical bottlenecks and problems solved by the project, market demand prospects, popularization and application fields, technical level achieved, and the role of the project in national economic development after completion.
At present, in the treatment of urban sewage and sludge in China, it is common to attach importance to the construction of sewage treatment facilities and ignore the matching of sludge treatment facilities; Pay attention to maintaining the operation of sewage treatment facilities, ignoring the harmless, stable and standardized disposal of sludge, resulting in a large number of sludge after sewage treatment can not be effectively disposed of, resulting in new pollution. The treatment and disposal of municipal sewage sludge has become an urgent environmental problem in China. In addition to the historical reason that the large-scale construction of sewage treatment plants in China began with the introduction of foreign capital and technology, an important reason is the lack of urban sewage sludge treatment and disposal system technology which is suitable for China's national and regional conditions and has the characteristics of safety, environmental protection and economy. Especially after sludge aerobic fermentation treatment technology (i.e. stockpiling) and land use are included in the national sludge treatment and disposal technology policy and listed as the best feasible technology, it is more important to study and develop its integrated and practical technical system.
In order to effectively solve the problem of municipal sewage sludge treatment and pollution control, our company has set up the first professional team of sludge pollution control in the province, organized scientific research personnel to tackle key problems in production, learning and research, applied biotechnology, multifunctional and efficient machinery, environmental mineral materials and the latest research results of soil fertilizers in China, followed the principle of aerobic fermentation and microbial degradation of organic matter in sludge, and at the same time, the heat released by aerobic reaction formed a high temperature greater than 55 degrees Celsius to kill pathogenic microorganisms. The final sludge product meets the harmless index, stabilization index and sludge pollutant limit value (maximum allowable content), forming an integrated supporting technical system for urban sewage sludge aerobic fermentation treatment and land use sludge treatment. The technical system specifically includes: multifunctional material processor (national patent), aerobic fermentation facilities, micro-electric temperature controller, post-treatment and comprehensive treatment of odor and heavy metal pollution. The demonstration project of this engineering technology has been completed in Zhangye Sewage Treatment Plant. The integrated supporting technology of sludge treatment and disposal conforms to the requirements of process flow, process parameters, pollutant reduction and pollution prevention measures, technical and economic applicability, land use, etc. of "Best Available Technology for Pollution Prevention and Control of Sludge Treatment and Disposal in Urban Sewage Treatment Plants" (for Trial Implementation) issued by the Ministry of Environmental Protection on February 20 10.
This project adopts the core equipment and multi-functional processors with independent property rights, and develops the integrated technology of urban sewage sludge treatment and pollution prevention suitable for the environmental conditions and economic level of our province and northwest China, which fills the gap that more than 80% of small and medium-sized sewage treatment plants in China do not have special equipment and system technology for sludge treatment and disposal. The technology of this project was originally based on the technical policy orientation of "sludge treatment and disposal, new technology and new equipment suitable for China's national conditions and regional characteristics".
The project effectively uses aerobic fermentation bio-composting technology, which has the characteristics of no additional energy, zero emission, full recovery, no secondary pollution and recycling of organic wastes. It treats sludge with high efficiency, energy saving and low cost, and successfully solves the contradictions and problems between regional economic level and investment threshold, technical barriers and promotion, pollution control and resource utilization in the current urban sewage sludge treatment. The project is in line with the national policy orientation of reducing pollution, developing low-carbon economy and building ecological civilization.
Chapter II Project Implementation Plan
2. 1. Pre-project work: the pre-project work that has been carried out, the existing supporting conditions of the enterprise, the source of technology or achievements, intellectual property rights, technical or artistic characteristics, etc.
2. 1. 1 Pre-project Work
Municipal sewage sludge bio-composting treatment and disposal technology involves microbiology, bioengineering, physics, chemistry, machinery, architectural design, fertilizer manufacturing, plant nutrition and other multidisciplinary fields. Experts jointly applied for the 2009 National 863 Plan in the field of resources, environment and technology with the theme of "Development and demonstration of high-efficiency bio-composting of municipal sludge and safe utilization of agriculture and forestry", which formed the theoretical basis, core technology research and development objectives and process route specifications. Practice has proved that. The technical route of this project conforms to the best feasible technical requirements put forward by the national Best Available Technical Guide for Pollution Prevention and Control of Sludge Treatment and Disposal in Urban Sewage Treatment Plants.
The completion of the sludge treatment demonstration project has enabled our company to have the ability of project planning, engineering, process design, core equipment research and development, product extension and development, land use and opening up a broad environmental protection market.
2, the source of technological achievements, intellectual property rights
3, process characteristics
This project uses the self-developed "Multifunctional Disposal Machine for Municipal Sewage and Sludge Compost Materials" which can perform crushing, mixing, stirring, conditioning, inoculation and even granulation operations at the same time, develops integrated supporting technologies suitable for sludge composting in northwest China, solves technical problems such as material conditioning, deodorization, heavy metal digestion, extension and appreciation of compost products, and develops and produces a variety of special fertilizers and their supply. There is no similar literature report in China.
2.2. Main contents, objectives and innovations of R&D or construction of the project: including technical features, key technologies and key processes that need to be supplemented or major research and test facilities, instruments and equipment and related supporting software; Implementation mode (independent development, digestion and absorption, international cooperation), technology and process route; Project schedule and implementation period.
1. The integrated technology for pollution prevention and control of sludge aerobic fermentation and biological composting treatment includes: key equipment for conditioning and pretreatment of sludge fermentation materials, multifunctional processor for municipal sewage sludge compost materials (authorized by national patent), core equipment of "sludge aerobic temperature control dynamic composting engineering technology", and unit technologies such as nutrient volatilization control and extended value-added development of sludge compost products. The technology of this project has the characteristics of no extra energy, no secondary pollution, zero emission, full recovery, energy saving and low consumption, high efficiency and practicality, and it conforms to the technological process, technological parameters, pollutant reduction and pollution prevention measures, technical and economic applicability and land use requirements of the Best Available Technical Guide for Pollution Prevention and Control of Sludge Treatment and Disposal in Urban Sewage Treatment Plants issued by the Ministry of Environmental Protection in February 20 10.
2.20 10 completed the research and development of the system technology of "aerobic fermentation composting technology and equipment for accumulated sludge". In order to shorten the gap between China's urban sewage and sludge treatment technology and developed countries, we have integrated innovation on the basis of absorbing and digesting foreign advanced sludge treatment equipment. The developed "sludge aerobic temperature control dynamic fermentation composting technology and equipment" is the second generation core technology of our company and will be used in the construction of this project.
Because of its simple structure and high production efficiency, Dano fermentor is the main equipment commonly used to treat solid wastes such as sludge in economically developed countries. This technology 1933, which appeared in Denmark, has been used in more than 50 factories around the world for nearly 80 years, but no one has made a breakthrough improvement to make it more perfect and efficient. First of all, our company innovatively adjusted the unreasonable process, shortening the primary fermentation time from 3-4d to 12h. The microbial flora of fully decomposed compost products has increased by two orders of magnitude, which is a good bio-organic fertilizer. At present, the design drawings of the key equipment of this technology have been sent to the entrusted manufacturer for review to evaluate its technical rationality, and the relevant patents are being declared. The popularization and application of this technology will accelerate the process of sewage sludge treatment and disposal in China, especially in the northwest region, and make positive contributions to achieving the national pollution reduction targets and completing the "Twelfth Five-Year Plan" for environmental protection.
Chapter III Project Construction Objectives
3. 1, technical performance indicators and parameters:
3. 1. 1, indicator:
1, the water content of sludge after aerobic fermentation is less than 40%;
2. The degradation rate of organic matter is more than 40%;
3. The mortality rate of eggs is over 95%;
4. The fecal coliform count was 0.01%(GB18918-2002).
3. 1.2, parameter:
Before aerobic fermentation: adjust the water content of sludge mixture to 55% ~ 65%, the carbon-nitrogen ratio (C/N) is 25: 1 ~ 35: 1, the organic matter content is usually not less than 50%, and the pH value is 6 ~ 8.
2. The fermentation period is about 15d, and the temperature is above 55℃ for 5 ~ 7d.
3. When aerobic dynamic fermentation is used, the fermentation time is 12h, the aging period is 5 ~ 6d, and the temperature is kept at 60℃ for more than 3d.
4, dynamic aerobic fermentation forced ventilation, 0.05 ~ 0.2 m3/mm per kloc-0/m3 material ventilation. ..