Comparison of seven sludge drying treatment processes
The main process of sludge treatment and disposal:
1. Sludge anaerobic fermentation
2. Sludge aerobic composting
3. Sludge incineration power generation
4, sludge sanitary landfill
5, rotary kiln drying
6, plate frame secondary pressure filtration
7, the curing agent is stable
Below, the author will explain the core technical characteristics of various processes for your reference.
1. Sludge anaerobic fermentation
Anaerobic three stages: hydrolysis, fermentation, and methanogenesis. * Stage hydrolysis is the conversion of particulate matter into soluble compounds; in the second stage of fermentation, the end product of the fermented zui is the precursor of methane formation; the third stage produces methan, the acetic acid splits methanogen and hydrogen uses methane to produce methane.
Disadvantages:
1. Large investment, high operating costs and safety issues.
2. The sludge needs to be preheated to consume a lot of heat energy, which cannot meet the needs of maintaining itself.
3. A large amount of biogas residue is produced and needs to be treated again.
4. Methane gas is difficult to be incorporated into the municipal pipe network.
5. The northern region cannot run in winter.
6, security risks, a large area.
At present, there are more than 50 in China, 29 of which have ceased operations.
Second, sludge aerobic composting
Use straw and other auxiliary materials to reduce the moisture content of the sludge to 60%, increase the gap to the specified CN ratio, continuously replenish oxygen, and ferment and humify after 25-30 days. Stabilization can be used as landscaping and land improvement.
Mainly include: natural compost, closed compost, drum compost, vertical multi-layer compost, etc.
Disadvantages:
1. Sludge muddy is unstable, medium and heavy metals are difficult to stabilize, and can only be used as landscaping fertilizer.
2. The composting process produces a large amount of odor and pollutes the surrounding environment.
3, adding a large amount of straw and other conditioning agents, continuous oxygen supply, operating costs of more than 200 yuan / t.
Third, sludge incineration power generation
The core equipment incinerator has a main equipment in the shape of a tower, a perforated plate at the bottom, a heating body sand placed on the plate as a combustion bed, a refractory material lining the tower, gas is introduced from the bottom, and the sludge enters into a boiling fluidized state. .
Disadvantages:
1. The investment is large, the boiler is seriously corroded, and the maintenance cost is high.
2, water content 80% sludge heat value is low, incineration consumes a lot of energy, mixed with 1 ton of standard coal 70Kg, operating costs of 300-400 yuan / t.
3, the impact on exhaust emissions is large, easy to produce harmful gases such as dioxins.
Fourth, sludge sanitary landfill
Domestically, it mainly mixes landfill with garbage and builds landfill sites at a cost of 50-60 yuan/t. It is easy to pollute water sources, the atmosphere, and covers a large area. There are potential safety hazards. At present, the land resources used for landfill in China are tight and dirty. The mud fill channel will soon have no way out.
Five, rotary kiln drying machine
The sludge is dried and dehydrated using energy such as coal or natural gas.
Disadvantages:
1. High energy consumption and high operating cost of 300 yuan / ton.
2, high temperature drying is easy to produce odor.
3. The dust control requirements in the drying process are strict and there are potential safety hazards.
Sixth, plate frame secondary pressure filtration
The sludge is diluted by about 90%, and after adding the chemical, secondary filtration is carried out.
Disadvantages:
1, the water content can only be 75-65%.
2, adding a large number of chemicals, increase the dry weight of the sludge, the operating cost is higher 180 yuan / t.
3. The limitations of sludge reuse increase.
Seven, curing agent is stable
Lime and other curing agents are added to the original sludge to chemically react with the sludge to release a large amount of heat and reduce the water content.
Disadvantages:
1. Add a large amount of lime and aluminum-based materials and increase the sludge.
2. The sludge cannot be reused and can only be landfilled.
3. The operating cost is higher 130-150 yuan / ton.
At present, it is difficult to meet the sludge treatment and disposal requirements by relying on a single process. According to different regions and different sludge types, considering the climate, regional characteristics, construction conditions, etc., it is an ideal choice to combine various processes to achieve good results.
In the choice of sludge treatment technology, no zui is good, only zui is suitable.
Plant growth regulators are organic compounds that are artificially synthesized (or natural extracted from microorganisms) and have growth and development regulation similar to natural plant hormones. Insen Biotech is specilized in Plant Growth Stimulants with large capacity and competitive price, including 1-naphthylacetic acid, Indole acetic acid(IAA), Indole butyric acid(IBA), Triacontanol, Diethyl aminoethyl hexanoate(Da-6), Brassinolide, 6-benzyladenine(6-BA), Forchlorfenuron(CPPU), Gibberellin acid(GA3).
Plant Growth Regulator,Indol Butyric Acid,Plant Growth Stimulant,Indole Butyric Acid
Hunan Insen Biotech Co., Ltd , https://www.insenhealth.com