Method for decreasing sewage sludge from town and changing it to resources

A technology for urban sewage and recycling, applied in the field of urban sewage sludge reduction and recycling, can solve the problems of limited sludge mixing, low resource utilization rate, large loss on ignition, etc., and achieve a clear environmental Benefit, obvious reduction effect, no secondary pollution effect
CN1915868AInactive Publication Date: 2007-02-21TSINGHUA UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
TSINGHUA UNIV
Publication Date
2007-02-21
Estimated Expiration
Not applicable · inactive patent

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Abstract

This invention discloses a method for treating sludge in city wastewater. The method comprises: (1) pulverizing sludge by ultrasonication so that large quantities of organic matters enter into the liquid; (2) treating the sludge by anaerobic / aerobic biodigestion to obtain organic macromolecular matters; (3) treating by anaerobic biodigestion to convert the majority of the organic matters into methane for utilization; (4) purifying the small molecular organic matters by aerobic biodigestion to obtain humic acid in the supernatant; (5) separating and recovering humic acid by membrane separation technique so that the output water satisfies state wastewater discharge standards. The obtained humic acid can be used as an organic liquid fertilizer. The method can be used to treat primary-precipitation sludge, residual active sludge, humic acid sludge and mixed sludge produced by city wastewater treatment plants. The obtained organic liquid fertilizer is safe and reliable.
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Description

technical field

[0001] The invention belongs to the technical field of solid waste treatment and disposal, and in particular relates to a method for reducing and recycling urban sewage sludge. Background technique

[0002] At present, the urban sewage treatment rate in my country is 42%, and the annual discharge of sewage sludge is about 1.3 million tons (dry weight), and the annual growth rate is greater than 10%. If all urban sewage is treated, the annual sludge output will reach 8.4 million tons (dry weight), accounting for 3.2% of my country's total solid waste. In addition to ash and organic matter, sludge also contains a large number of toxic and harmful substances such as germs, parasites, and heavy metals. Improper treatment can easily cause serious secondary pollution. Therefore, the way out to solve a large amount of urban sewage sludge is to find ways to reduce and recycle sewage sludge.

[0003] Sludge contains a large amount of organic matter, and its composit...

Claims

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