How Do You Choose Sludge Dewatering Technologies?
Sludge dewatering technology is a sludge treatment method that removes the fluid from the native or concentrated sludge and converts it into a semi-solid or solid sludge.
After dewatering, the moisture content of sludge can be reduced to 20% to 30% ( depending on the nature of sludge and sediment and the efficiency of dewatering equipment ), which can save on the transportation costs, reduce land occupation, and provide reduction, sanitation and economic conditions for other final disposals.
The further dewatering of sludge is referred to as sludge drying, and the moisture content of dried sludge is less than 10%.
A typical sludge dewatering process generally includes four stages of treatment.
First stage is sludge concentration, the main purpose is to reduce initial capacity of sludge to reduce the volume of subsequent treatment structures;
Second stage is sludge digestion, which is mainly to decompose the organic matter in sludge;
Third stage is sludge dewatering for further reducing the sludge capacity;
Finally stage is sludge disposal, in which the final sludge is absorbed by a certain way.
The supernatant or filtrate produced in the above stages still contains a large amount of pollutants and should be returned to the sewage treatment system for treatment.
Problems with traditional sludge treatment:
1.Dry sludge generally contains 65% organic matter and 35% inorganic matter.
2.The wet sludge contains a variety of bacteria, viruses and parasites in which the bacteria multiply.
New Sludge dewatering technologies
The vacuum filter dewatering machine can be continuously produced and can be controlled automatically. However, there are many auxiliary equipments, and the filter cloth needs regular backwashing. The operation process is complicated, the filter cloth is also easy to be blocked, and the sludge has high moisture content after dewatering. Generally, it is only used for digestion. Sludge dewatering.
2.Plate and frame filter
The plate frame filter press has good dewatering effect and low price. After dewatering, the sludge moisture content is low, the labor operation intensity is general, the operation management and the cost are moderate. Plate and frame pressure filtration is used in the design of the process.
The belt filter press is a widely used sewage dewatering equipment. The filter belt can be rotated, continuously operated, and the sludge treatment effect is stable.
Centrifugal dewatering is expensive, motor power is high, and operating costs are high. Only for large wastewater treatment projects. Therefore, this project should not be used.
The above typical sludge dewatering process can solve the problems of traditional sludge dewatering methods and make the sludge after treatment to achieve “four transformations”:
1.Reduction the sludge capacity.
2.Realize sludge stabilization.
4.Realize the sludge resource.