Municipal sludge treatment method

Abstract

The invention discloses a municipal sludge treatment method. The method comprises the steps: (1) sludge pretreatment: mixing rice straws and bagasse according to the mass ratio of 2 to 1, then, carrying out cutting to form small segments, so as to obtain straw chips; selecting sand grains: mixing the straw chips, the sand grains and sludge according to the mass ratio of 2 to 1 to 6, so as to obtain mixed sludge; drying the mixed sludge in the air or baking the mixed sludge until the moisture content is 15% to 20%, and then, carrying out heap fermentation for 20 to 30 days, so as to obtain pretreated sludge; (2) sludge cutting: putting the pretreated sludge into a water jet cutting device for cutting, so as to obtain mud; (3) sludge impurity removal: filtering the mud to filter off solid impurities with the particle size of 1.5cm or more, so as to obtain impurity-removed mud; (4) sludge grinding: grinding the impurity-removed mud by using a grinding device, so as to obtain ground mud; (5) solid-liquid separation of sludge: performing solid-liquid separation on the obtained ground mud by using a solid-liquid separator, thereby obtaining treated finished sludge.

Description

technical field [0001] The invention relates to the technical field of environmental protection, and more specifically, the invention relates to a municipal sludge treatment method. Background technique [0002] Sludge, such as the sludge produced in urban life, contains impurities such as heavy metals, plastics, organic matter, and bacterial organisms. The random discharge of sludge not only pollutes the air, but also easily pollutes groundwater. Sludge needs to be treated before it can be reused. [0003] The existing municipal sludge treatment methods mainly include fermentation and accumulation of sludge, heavy metal removal treatment, and sundry screening treatment. There are following problems in these existing methods: [0004] 1) The method of accumulating fermentation takes too long and the fermentation is uneven; [0005] 2) In the step of heavy metal removal treatment, the sludge is mixed with the heavy metal removal agent by means of spiral blade stirring. The...

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Problems solved by technology

[0004] 1) The method of accumulating fermentation takes too long and the fermentation is uneven;

[0005] 2) In the step of heavy metal removal treatment, the sludge is mixed with the heavy metal removal agent by means of spiral blade stirring. The spiral blade cannot effectively disperse the sludge, resulting in poor mixing effect. At the same time, there are still many large particles in the sludge. Heavy metals wrapped in large particles cannot be mixed with the agent, resulting in poor removal of heavy metals;

[0006] 3) The debris screening process is mainly carried out through ordinary filter screens. Sludge is easy to adhere to the filter screen, which not only increases the burden on the filter screen, but also blocks the filter holes, which seriously affects the speed of screening.

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