Sludge alkaline pyrohydrolysis treatment method and system

Abstract

The invention discloses a sludge alkaline pyrohydrolysis treatment method and system, the sludge alkaline pyrohydrolysis treatment system comprises a conditioning tank, a pyrohydrolysis reactor communicated with the conditioning tank, and a neutralization reaction tank communicated with the pyrohydrolysis reactor, the pyrohydrolysis reactor is connected with a first dosing tank, the first dosing tank is filled with a KOH solution, the neutralization reaction tank is communicated with a plate-and-frame dehydrator, a filter screen is arranged on the plate-and-frame dehydrator, and sludge finallypasses through the filter screen of the plate-and-frame dehydrator to obtain a liquid fertilizer and a solid mud cake. The method has the beneficial effects that before the sludge is subjected to pyrohydrolysis, alkali is firstly added to enable the pH value of the sludge to be 10-12, compared with pyrohydrolysis, the solubility of COD and VSS of the sludge subjected to alkaline pyrohydrolysis isbetter, a K element can be introduced while the pH value is adjusted through KOH, potassium is an indispensable nutrient substance for plants, and the content of the K element is increased for the subsequently generated liquid fertilizer while the hydrolysis rate is accelerated. The process has the characteristics of high resource utilization rate and environmental friendliness.

Description

technical field [0001] The invention relates to the technical field of sludge incineration, in particular to a method and system for alkaline thermal hydrolysis treatment of sludge. Background technique [0002] Sludge in urban sewage treatment plants is a by-product of sewage treatment. In recent years, with the continuous improvement of urban sewage treatment rate, the output of sludge has also increased, and the resource utilization of sludge has also become an important scientific research in environmental protection. direction. The thermal hydrolysis treatment of sludge is to react the sludge at a certain temperature and pressure for a certain period of time to destroy the floc structure of the sludge, thereby improving the solubility of the solid phase. However, this thermal hydrolysis method has high energy consumption, low solubility of organic matter, and requires additional fuel to preheat the sludge. [0003] Existing sludge thermal hydrolysis processes often ad...

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Problems solved by technology

However, this thermal hydrolysis method has high energy consumption, and the solubility of organic matter is not high, and additional fuel is required to preheat the sludge

[0003] The existing sludge thermal hydrolysis process often adds Ca(OH) 2 solution, alkaline thermal hydrolysis can accelerate the rate of thermal hydrolysis compared with traditional thermal hydrolysis, but the addition of calcium element will lead to the subsequent formation of some calcium-containing precipitates such as calcium oxide, and the final solid product will increase, and the solid product cannot Continue to use, resulting in greater waste

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