Method for dry-treating municipal sludge by biological dehydrating machinery

Abstract

The invention relates to a method for processing the mud in the city waste water processing factory, including the following steps of: a. mixing the dehydrated mud in the waste water processing factory (moisture content 78%) with mechanically dried mud particles with moisture content of 10% below to make the moisture content down to 50%-55%; b. adding biodehydrating bacterial strains into the biodehyrating tank; c. biochemical raising temperature and reacting for 8-10 days to make the moisture content down to below 35%; d. feeding the biodehydrated city mud with moisture content of below 35% into a mechanical drying system for drying to make the moisture content down to below 10%, returning a part of finished mud particles to mix with wet mud; e. the rest is the final product of the city mud processing and able to be used as fuel and soil modifying agent or is buried finally. The invention largely reduces operating expenses and applies to large scale mud processing and can make multichannel processing according to mud quality.

Description

technical field [0001] The invention relates to a treatment method for sludge in a municipal sewage treatment plant. Background technique [0002] Sewage treatment plants using secondary treatment processes will generate a large amount of sludge during operation. Sludge contains a large amount of organic matter, pathogenic bacteria, heavy metals and other toxic and harmful substances. At present, treatment equipment for sludge digestion and concentration and dehydration are generally installed in sewage plants. After these treatments, the moisture content of the sludge can be reduced to about 80%, but still contains a large amount of pollutants. If it is not disposed of properly, it is bound to bring serious pollution to the environment. At present, there are several disposal technologies for dewatered sludge in sewage plants in the world: composting, drying, incineration, landfill, melting, etc. Landfill has been gradually banned by developed countries because it will c...

AI Technical Summary

Problems solved by technology

For example, in the patent application with the application number: "00132414.4", the fermentation time is about 4 weeks, which is not conducive to large-scale sludge disposal. The final drying method uses a drying method at 60 degrees Celsius, and the drying time Long and low temperature are not suitable for sterilization; in the patent application with application number "03129102.3", the moisture content of the product is 10% to 20%, which is not conducive to resource utilization, and the drying temperature is 80 degrees Celsius, which is not conducive to sterilization

In addition, the common disadvantage of the above two technologies is that they are both a way of making fertilizers, which cannot be used when the heavy metal content of municipal sludge does not meet the standard (this is very common), and these two technologies are not suitable for Large-Scale Sludge Disposal

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