Sludge treatment process based on hydrothermal modification technology

Abstract

The invention relates to a sludge treatment process based on a hydrothermal modification technology. The sludge treatment process is carried out by comprising the following steps of: (1) temporarily storing the sludge which is subjected to mechanical dehydration and has the water content of 70-85% to a pretreatment unit and deodorizing the sludge; (2) introducing to a homogeneous device, fully mixing and homogenizing, introducing the homogenized sludge to a slurrying device, introducing the slurried sludge to a hydrothermal reactor for hydrothermal reaction, and introducing the hydrothermal sludge to a flash evaporator for decompression and flash evaporation; (3) cooling to 35-45 DEG C by using a cooler, then introducing to a high-pressure diaphragm pressure filter for pressure filtering and dehydration to obtain a dehydrated mud cake with the solid content of 35-45% and dehydrated filtrate; (4) introducing the dehydrated filtrate to an intermediate temperature anaerobic reactor, wherein the residence time is for 5.5-7.5d, the inlet water temperature is controlled below 40 DEG C, and the anaerobic reaction temperature is 30-40 DEG C; and (5) preparing a biomass fuel rod by using the dehydrated mud cake, and introducing the biomass fuel rod to a boiler to provide steam for the hydrothermal reactor and the flash evaporator. The sludge treatment process has the advantages of goodtreatment effect, obvious volume reduction effect, high harmless degree, recycling of methane, good economic benefit and the like.

Description

technical field [0001] The invention relates to a sludge treatment process based on hydrothermal modification technology, which is suitable for various sludge treatment, especially for municipal sludge treatment. Background technique [0002] Municipal sludge is a by-product produced in the process of urban sewage treatment, which is a complex heterogeneous body composed of organic debris, bacterial cells, inorganic particles, colloids, etc. It mainly has the following characteristics: [0003] (1) High moisture content. The moisture content of sludge is as high as 99%, and the conventional dehydration performance is poor. The sludge treated by mechanical dehydration equipment generally has a moisture content of more than 80%, forming a thick substance between liquid and solid, which is soft and easy Flow state, poor soil mechanical properties. [0004] (2) More than 50% of the COD reduced in sewage treatment is converted into cells and enters the excess sludge. Therefore...

AI Technical Summary

Problems solved by technology

[0005] (3) Sludge usually contains a certain amount of toxic and harmful substances, such as parasite eggs, pathogenic microorganisms, heavy metals and organic chemical toxic substances. If it is not disposed of properly, it is easy to cause secondary pollution

[0012] If it is incinerated, due to its high water content and low calorific value, it is necessary to add auxiliary fuel, which will increase the operating cost of incineration, and improper operation will easily form carcinogenic pollutants such as dioxins and furans due to incomplete combustion.

[0013] Therefore, there are many problems to be solved in the treatment of municipal sludge, and because it has not received enough attention and improper disposal methods, it has become a potential source of danger affecting the appearance of the city and ecological safety, but its potential for resource utilization is obvious. Therefore, municipal sludge has the dual characteristics of waste and resources, which can be said to be a typical "misplaced resources"

Images