Dehydration conditioner for high temperature anaerobic digested sludge and dehydration method of high temperature anaerobic digested sludge

Abstract

The invention discloses a dehydration conditioner for high temperature anaerobic digested sludge and a dehydration method of high temperature anaerobic digested sludge. The dehydration conditioner comprises an acryloyloxyethyl trimethyl copolymer and cationic polyacrylamide, the weight ratio of the acryloyloxyethyl trimethyl copolymer is 1.1%-1.37% of the solid content of the high temperature anaerobic digested sludge, and the weight ratio of the cationic polyacrylamide is 0.27%-0.36% of the solid content of the high temperature anaerobic digested sludge. The dehydration method of the high temperature anaerobic digested sludge adopts the dehydration conditioner for conditioning. The dehydration conditioner provided by the invention has the advantages of no corrosiveness, no increase of sludge ash content, no change of the properties of the filter cake and filtrate, good dehydration performance, good applicability, low cost, no secondary pollution, etc., is an environment-friendly conditioner that has good application prospects and can efficiently condition high temperature anaerobic digested sludge, and can achieve the advantages of simple method, good dehydration effect and the like when used for dehydration of high temperature anaerobic digested sludge.

Description

technical field [0001] The invention belongs to the field of sludge treatment, and relates to a dehydration conditioner for anaerobic digestion sludge, in particular to a dehydration conditioner for high-temperature anaerobic digestion sludge and a dehydration method for high-temperature anaerobic digestion sludge. Background technique [0002] Sludge has complex components, including pathogenic microorganisms, parasite eggs, toxic and harmful heavy metals and a large amount of refractory substances. If it is not handled properly, it will easily cause secondary pollution to the environment. At the same time, sludge also contains a lot of rich nutrients, which can be used as fertilizer after proper treatment to improve soil and promote plant growth; the biogas produced after fermentation treatment can be used as energy material to alleviate energy problems. [0003] As one of the important technologies for sludge treatment, anaerobic digestion can effectively convert part of ...

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Problems solved by technology

[0004] At present, the selection range of dehydration conditioning agents used for chemical conditioning of anaerobic digested sludge is relatively small. The commonly used dehydration conditioning agents are inorganic salt + polyacrylamide (PAM) or inorganic salt compound. Sludge conditioning can improve the dehydration performance of the sludge, but it will also bring a series of problems: the addition of inorganic salts will increase the conductivity and other indicators, which will cause serious corrosion of the treatment equipment due to the improvement of electrochemical corrosion performance. The use of salt will greatly increase the ash content in the sludge, which will result in a large amount of sludge production and is not conducive to the subsequent resource utilization of sludge. It is easy to harden, and when it is used for incineration, the incineration calorific value is insufficient due to the high content of ash. At the same time, adding a large amount of inorganic salts will also change the properties of the filtrate. For example, a large amount of inorganic salts will be introduced into the filtrate, resulting in complex components of the filtrate. The biochemical properties of the reduced filtrate are poor, and it is easy to cause secondary pollution (such as iron salts can easily cause water chroma to increase, and aluminum salts can easily cause aluminum ions in water to exceed the standard)

In a centralized sludge treatment project in Changsha, the method of conditioning high-temperature anaerobic digested sludge uses "ferric chloride + PAM" as the dehydration conditioner. When the dehydration conditioner is used for conditioning, due to the The dosage is as high as 5-6% of the solid content, which leads to serious corrosion of the treatment equipment, and also significantly increases the ash content in the sludge, and there are a lot of inorganic substances in the filtrate obtained after the conditioned high-temperature anaerobic digestion sludge is press-filtered. Salt, with poor biochemical properties, the resulting mud cake has a large amount, is easy to harden, and has high hardness, so it cannot be used for subsequent recycling

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