A method of joint treatment of municipal sludge using energy grass and anaerobic fermentation technology

Abstract

The invention discloses a method for processing municipal sludge by combining energy grass with an anaerobic fermentation technology. Different processing methods are adopted according to the properties of primary sludge and active sludge, and the active sludge with high content of organic matters and fresh energy grass are mixed and undergo anaerobic fermentation stable treatment; and the primary sludge with high content of inorganic matters and biogas residues are mixed and are stabilized by a plant (energy grass) land system, so the method adapts to different sludge characteristics, solves the problems of low anaerobic fermentation system utilization efficiency caused by much mud sands in sludge, difficult finding of the carbon source required by fermentation and the like, overcomes the disadvantages of difficult recycling of traditional sludge processing methods, and simultaneously realizes municipal sludge processing and energy regeneration and recycling comprehensive utilization; and a soil conditioner is prepared through a plant stabilizing technology, so a way is found to finally process sludge, and the utilization value of sludge is maximized.

Description

Technical field: [0001] The invention relates to the technical field of waste resource utilization, in particular to a method for jointly treating municipal sludge by using energy grass and anaerobic fermentation technology. Background technique: [0002] With the development of the economy and the acceleration of the urbanization process, the sewage treatment rate in our country is increasing day by day, and the output of municipal sludge as an inevitable subsidiary product of sewage treatment is also increasing day by day. At present, there are more than 3,000 sewage treatment plants in the country, with a daily sewage treatment capacity of 140 million tons, and a sludge production volume (based on a moisture content of 80%) of more than 140,000 tons per day. Sludge contains toxic and harmful substances such as pathogens, heavy metals and persistent organic compounds. Without effective treatment and disposal, it will easily cause secondary pollution to groundwater and soil...

AI Technical Summary

Problems solved by technology

[0007] (1) The optimal carbon-to-nitrogen ratio for anaerobic fermentation is 25-30, while the carbon-to-nitrogen ratio of sludge is low (10-20), the fermentation gas production is unstable, and carbon sources often need to be added, and it is difficult to find a suitable carbon source ;

[0008] (2) Primary sludge (with large sand content and many inorganic substances) and activated sludge are not treated differently, resulting in a high content of inorganic substances such as mud and sand in the fermentation material, which not only occupies the reactor volume, but also affects the anaerobic fermentation effect;

[0009] (3) Sludge often contains trace amounts of heavy metals, and only anaerobic digestion cannot reduce the content of heavy metals;

[0010] (4) Less gas production and lower energy recovery rate

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