Current Status and Technical Prospects of Sludge Treatment and Disposal in my country

9.
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2 Current status of sludge treatment and disposal in my country

Distribution of sludge treatment and disposal methods: harmless + stabilization + land use about 10%, dry incineration + building materials use about 15%, simple landfill + random disposal (without any stabilization or harmless treatment) about 75 %
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Sludge treatment methods and current situation: sludge dewatering has been popularized.
There are more than 100 sewage treatment plants for high-dryness dewatering of sludge, 60 anaerobic digestion plants (less than 15 in operation), about 35 aerobic fermentation and drying Incineration/cooperative incineration of about 15 buildings
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For example, the treatment and disposal methods adopted by several first-tier cities are anaerobic digestion in Beijing, desiccation-incineration in Shanghai, and in-plant desiccation-cooperative incineration in Guangzhou

The problems in sludge treatment and disposal in China are as follows
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①Large sludge output, large-scale sewage treatment plant, and concentrated sludge volume; ②Low sludge treatment and disposal rate, greatly reduced COD emission reduction (COD enriched in sludge accounts for 20%-50%); ③Sewage plant has concentration , Dehydration and other general technical links, but the raw sludge is directly mechanically dehydrated without gravity concentration, resulting in a large amount of cement removal.

9.
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3 Prospects of sludge treatment and disposal technologies

Researchers in various fields at home and abroad have carried out more research work on sludge treatment, such as research on sludge dewatering process and dewatering agent, research on controlling heavy metal pollution of sludge, research on dephosphorization of filtrate after sludge dewatering, ultra urban water oxidation treatment sludge, municipal sewage sludge wet oxidation treatment
.

Existing technologies and methods for the treatment and disposal of surplus sludge are diverse, but they are nothing more than two categories: "except for problems after completion" and "prevention of problems before they occur

"Removal of troubles after completion" refers to the treatment and disposal of the surplus sludge that has been produced, which is suitable for the sludge treatment unit of an existing sewage plant, or where the sludge is treated/disposed in a centralized manner
.

Looking forward to the future sludge treatment and disposal technology, technological innovation should be made in view of the characteristics of large sludge production, high sand content, and low organic matter in China, speed up key common technology research, and promote the optimized integrated application of complete sets of equipment and the entire industry chain; focus on technology development orientation To be "green, recycling, low-carbon", develop new technologies, medicaments, materials, new technologies and new principles and other original technologies to solve pollution problems while achieving maximum recovery of materials and energy; the choice of technology should follow the sludge The principles of total consumption, total energy balance, all green processes, and economic sustainability

Table 9-1 Comparison of the advantages and disadvantages of various current sludge reduction technologies

How to economically and effectively treat various sludges produced in the biological treatment of wastewater is still a worldwide problem
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For a long time to come, the study of sludge reduction needs to conduct comprehensive and systematic research and comparison from the principles and technologies, and select appropriate reduction technologies based on the specific physical and chemical characteristics of sludge in each sewage treatment plant