Treatment method for stabilizing and reducing municipal sludge

Abstract

The invention belongs to the technical field of comprehensive utilization of solid waste, in particular to a treatment method for stabilizing and reducing municipal sludge, which comprises the following detail steps of: reacting condensed sludge, which is produced by a sewage treatment plant and of which the water content is higher than 80 percent, with waterborne polyurethane dispersion emulsion for 2 to 24 hours at the temperature of 60 to 100 DEG C, and centrifuging the reactant for 15 to 60 minutes at a rotation speed of 3,000 to 10,000 revolutions per minute to obtain stabilized and reduced dehydrated sludge. The treatment method provided by the invention adopts two steps for treatment, namely blending modification of the waterborne polyurethane dispersion emulsion and dehydration of a centrifugal dehydrator; the water content of the treated sludge is low (less than or equal to 60 percent); heavy metal ions in the sludge can be effectively removed; treatment cost is saved; harmless quality is greatly improved; the yield of the sludge can be reduced by over 40 percent; and the treatment method has the advantages of simple equipment, low cost, no secondary pollution, simple and convenient operation and the like, and is suitable for the treatment of the sludge in a city and town domestic sewage plant.

Description

technical field [0001] The invention belongs to the technical field of comprehensive utilization of solid waste, and in particular relates to a treatment method for stabilizing and reducing municipal sludge. Background technique [0002] With the increasing scale of the city and the rapid development of the economy, the output of urban sludge is increasing and causing serious harm to the urban environment. The sharp increase in the amount of urban sludge has brought obstacles to urban construction, and urban sludge accounts for a large proportion of the huge urban garbage mountain. In recent years, due to years of accumulation and no effective treatment methods, sludge is seriously polluting the environment and has become a major public hazard. At present, domestic and foreign sludge treatment methods mainly include landfill, incineration and composting. The landfill method occupies a large area and requires infiltration treatment. It is also necessary to build a biogas re...

AI Technical Summary

Problems solved by technology

[0003] Chinese patent 01108478.2 (publication number CN1318435A) discloses a process for harmless and comprehensive utilization of lake and urban sludge, which is to salvage, collect and dry lake and urban sludge, and add sulfur-fixing agent and chlorine-fixing agent after batching Enter the melting furnace for harmless treatment, and the molten slag can be made into building materials, but the invention uses sludge incineration treatment in the preparation process, and the furnace temperature is higher than 1400 °C, the cost is high, the environmental protection requirements are high, and the application is limited

Chinese patent 01115480.2 (publication number CN1382652A) and Chinese patent 200710070477.7 (CN 101139158A) have also reported a process of first granulation (strip), then drying and incineration to carry out harmless and reduction treatment of sludge. Granular organic compound fertilizers can also be produced, but sludge incineration treatment and drying processes are still used in the preparation process, which has high cost, high environmental protection requirements, and limited application

Chinese patent 200410071133.4 (CN 1727292A) discloses a method for integrating sludge drying and high-temperature aerobic composting fermentation technology. The process first uses drying technology to semi-dry the sludge with a moisture content of ≤80%, and then The treated sludge is subjected to high-temperature aerobic composting fermentation treatment to realize sludge harmless and resourceful treatment. However, due to certain defects in high-temperature aerobic composting technology, drying technology is still mostly used in municipal sludge disposal at home and abroad. mainly

However, this method needs to invest in large quantities and different types of polymer flocculants, which has high cost, many reaction steps, and poor economic benefits.

Chinese patents 200510102944.0 (CN 1765780A) and 200610112790.8 (CN 1915868A) both disclose a method of using ultrasonic treatment of sludge to reduce the amount of sludge, but the technology of ultrasonic treatment of sludge is currently in the stage of laboratory research. There is still a long way to go before the engineering application, and this method still needs to invest a lot of flocculant and dehydration treatment

However, the above-mentioned technologies generally have disadvantages such as immature technology, high operating costs, and large investment.