Integrated treatment method and system for sludge

Abstract

The invention provides a sludge integrated treatment method and system, the sludge integrated treatment method comprises pyrohydrolysis pretreatment and anaerobic digestion of sludge and heat drying treatment of biogas residue after anaerobic digestion, and the temperature of anaerobic digestion is 35-38 DEG C. Through combination of pyrohydrolysis pretreatment, medium-temperature anaerobic digestion and thermal drying treatment, the sludge with the water content of 20-30% can be obtained by treating the raw sludge. Meanwhile, the organic matter removal rate is high, the methane yield is high,the treatment period is short, and reduction, recycling and stabilization of the sludge are greatly achieved.

Description

technical field [0001] The invention relates to the technical field of sludge treatment, and more specifically, to an integrated sludge treatment method and system. Background technique [0002] Sludge is a by-product of the sewage treatment process. It has the characteristics of high water content, fine particles, and light specific gravity. It mainly comes from the primary sedimentation tank and secondary sedimentation tank of the sewage treatment plant. The sludge has complex components and a large amount, which contains a large amount of organic matter, nitrogen and phosphorus, pathogenic microorganisms, parasite eggs and viruses, heavy metal ions and other substances. The organic matter in the sludge is perishable and produces stench, which is easy to breed mosquitoes and flies; nutrients such as nitrogen and phosphorus will flow into the surface or underground water body under the washing of rainwater, causing water pollution; untreated or substandard treated sludge is...

AI Technical Summary

Problems solved by technology

However, there are many defects in the traditional anaerobic digestion system: first, the degradation rate of organic matter is low, generally less than 40% (calculated by VS), and the methane production rate is also low; secondly, the hydrolysis of complex polymers in sludge The rate is slow, resulting in a long hydraulic retention time HRT, generally 20-30d, resulting in a large-scale reactor and other facilities, high investment, and a large area; moreover, maintaining the medium-temperature digestion of the reactor requires a lot of energy and high operating costs

This method needs to add certain chemicals in the thermal hydrolysis link, and the accumulation of chemicals may bring certain risks to the pipelines of the high-temperature and high-pressure system; in addition, the stability of high-temperature anaerobic operation is relatively weak, and the inhibition of ammonia nitrogen is weak Weak and expensive to run

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