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​Sludge dryer

Anaerobic sludge digestion

Anaerobic digestion of sludge is a biological treatment method that decomposes organic matter under anaerobic conditions. Suitable for sludge with higher organic content.

Purpose of sludge anaerobic digestion


(1) Reduce sludge volume

Reduce the amount of organic matter in sludge and reduce the volume of sludge. Compared with before digestion, the volume of digested sludge can generally be reduced by 1/2 ~ 1/3.


(2) Stable sludge properties

Reduce the amount of decomposable and corruptible substances in the sludge to make the sludge stable.


(3) Improve the dewatering effect of sludge

The undigested sludge has a sticky, gel-like structure and is not easy to dehydrate. Digested sludge, colloidal material is gasified, liquefaction or decomposition, so that the water in the sludge and solids are easily separated.


(4) Use the methane gas produced

Sludge in the process of digestion to produce methane gas, methane gas in the useful account for about 2/3, can be used as fuel for power generation, burning boilers, driving machinery.


(5) Eliminate the stench

During the anaerobic digestion of sludge, hydrogen sulfide separates sulfur molecules or combines with iron to become iron sulfide, so the sludge after digestion will no longer give off odor.


(6) Improve the sanitary quality of sludge

Sludge contains a lot of toxic substances such as bacteria, pathogenic microorganisms, parasitic eggs, very unsanitary. In the process of sludge digestion, the methane bacteria produced has a strong antibacterial effect, can kill most of the pathogenic bacteria and other harmful microorganisms, so that the sludge sanitary.



Main design conditions to ensure good operation of the anaerobic digester


In order to make the digester in production have good digesting function, the optimization of design stage is very important. Not only do engineers need to design correctly based on knowledge of biological reaction processes, but the choice of pool shape and equipment is also important. Only under the corresponding physical boundary conditions can biological systems create the best operating effects. Therefore, the process design of the digester shall meet the following requirements:

(1) Appropriate pool shape selection;

(2) Optimal design parameters;

(3) Equipment that is energy efficient, efficient and easy to operate and maintain;

(4) Good stirring equipment can make the sludge in the tank mix evenly to avoid hydraulic dead Angle;

(5) The original sludge was evenly input and timely mixed with digested sludge for inoculation;

(6) Minimize heat loss, timely replenish heat, and minimize temperature fluctuation in the pool;

(7) The biogas generated by the digester can be transferred from the digesting sludge in time;

(8) Having good measures to destroy scum layer and remove scum;

(9) Having reliable safety protection measures;

(10) Flexible operating piping system.