The sludge floc is not tight, and the mud cake appears "runny" phenomenon, which may be caused by a variety of factors. The following is a specific analysis of these reasons:
One. Improper sludge conditioning
Lack of sludge conditioner or improper selection:
Before the sludge enters the filter press equipment, if the appropriate sludge conditioner is not added, or the selected sludge conditioner type is not appropriate, it may lead to the sludge can not form stable floc.
The choice of sludge conditioner should be determined according to the nature of the sludge (such as organic sludge or inorganic sludge) and the type of dewatering equipment.
Inadequate mixing of sludge and conditioner:
Insufficient mixing time or improper mixing method of sludge conditioner and sludge may lead to the sludge conditioner cannot be evenly distributed in the sludge, thus affecting the dewatering effect of the sludge.
Two, sludge properties
Sludge solid content is too low:
The small content of solid matter in the sludge may lead to poor water filtration of the sludge, large specific resistance, and then affect the dehydration effect.
No modification of hydrophilic groups on sludge surface:
The surface of biochemical sludge contains a large number of hydrophilic groups, if not modified by sludge conditioner, it may lead to low dewatering efficiency of sludge.
Uneven distribution of sludge particle size:
If the size difference of the particles in the sludge is large, it may lead to the formation of different sizes of floc during the dehydration process, and then affect the uniformity and tightness of the mud cake.
Three, equipment operation and maintenance problems
Uneven pressure distribution of filtration equipment:
In the working process of the plate and frame filter press and other equipment, if the uneven distribution of solid particles in the filter chamber may lead to the uneven distribution of pressure during the formation of the filter cake, thus affecting the tightness and uniformity of the mud cake.
Improper maintenance of equipment:
If the equipment is not thoroughly cleaned before and after use, residual sludge may clog the filter joints and rings, affecting the dehydration effect.
If the various parts of the equipment (such as spiral shaft, fixed ring, movable ring, etc.) are not regularly checked and maintained, it may also lead to poor dehydration effect.
Four. Other factors
Effect of pH value:
When the pH value in the wastewater treatment system is too low, the sludge may become unstable and not easily form tight floc.
Influence of REDOX potential:
If the REDOX potential in the wastewater is too high or too low, it may cause the sludge to lose stability and it is difficult to form tight floc.
To sum up, in order to solve the problem of not tight sludge floc and "runny" mud cake, it is necessary to start from many aspects such as sludge conditioning, sludge properties, equipment operation and maintenance and other factors. Specific measures include selecting the appropriate type of sludge conditioner, ensuring that the sludge is fully mixed with the sludge conditioner, adjusting the solid content and particle size distribution of the sludge, optimizing the operation and maintenance process of the filter press equipment, and controlling the pH value and REDOX potential of the wastewater treatment system.