The pollutants such as organic matter and pathogenic bacteria carried in domestic sewage will produce a large amount of sludge in the treatment process. So, how to dehydrate the sludge produced by the domestic sewage plant? Technical engineers at Works Chemical will provide you with a detailed overview of several common sludge dewatering treatments.
1. Chemical conditioning method - sludge conditioner
The sludge conditioner can destroy the bacterial structure, change the surface structure of the sludge, reduce the solid surface load of the sludge, reduce the specific surface area of the sludge surface, combined with the plate and frame mud press, can reduce the water content of the sewage plant sludge from more than 90% to 40%-60%, and fully realize the sludge reduction.
2. Gravity enrichment method
Gravity enrichment method mainly uses the gravity difference between sludge and water, so that the water in the sludge is gradually discharged through filtration, precipitation and other ways. The moisture content of the sludge after gravity concentration is low, and it can be easily processed by press filtration and centrifugation. However, the gravity enrichment method is suitable for the treatment of low concentration domestic sewage sludge, and the effect is poor for high concentration sludge.
3. Pressure filtration method
Pressure filtration method is a kind of dewatering treatment method that uses pressure difference to extrude water from sludge. The main equipment is the filter press, which makes the water in the sludge flow out through the filter medium by increasing the pressure. The pressure filtration method has the advantages of high treatment efficiency and strong adaptability, and is suitable for various types of sludge dewatering treatment.
4. Centrifugal dehydration method
Centrifugal dewatering method is a dewatering treatment method using the principle that the proportion of solid particles in the sludge is greater than that of water, and the water in the sludge is thrown out by centrifugal force generated by high-speed rotation. Centrifugal dewatering method has the advantages of small equipment investment and small footprint, but it has higher requirements for the properties of sludge and is suitable for sludge with good separation.
5. Air floating-gravity enrichment method
Air floating-gravity concentration method is a kind of sludge dewatering treatment method which combines air floatation and gravity concentration. Firstly, the suspended matter in the sludge is removed by air flotation technology. Then, the remaining sludge was dehydrated by gravity enrichment method. This method can not only effectively remove the suspended matter in the sludge, but also reduce the moisture content of the sludge.
In short, the sewage plant sludge dewatering treatment methods are various, each has advantages and disadvantages. In practical application, suitable dewatering treatment method should be selected according to the characteristics and treatment requirements of sludge to achieve effective disposal of domestic sewage plant sludge.