details

The process of using a belt filter press to concentrate or digest the liquid mixture into sludge, reduce or remove moisture, and convert it into semi-solid or solid sludge cake is called sludge dewatering. After dehydration, the moisture content of sludge can generally be reduced to 70-85%, depending on the properties of the sludge and sediment and the efficiency of the dewatering equipment. The further dewatering of sludge is called sludge drying, and the moisture content of dried sludge is generally less than 20%. The main methods of dehydration include natural drying and belt filter mechanical dehydration.

Classification of common sludge:

1. The remaining activated sludge discharged from the secondary sedimentation tank of the domestic sewage treatment plant;

Sludge classification: Belongs to hydrophilic, fine-grained organic sludge with poor compressibility and average dewatering performance.

2. Physical and chemical sludge discharged from sedimentation tanks or concentration tanks in water plants;

Sludge classification: It belongs to the category of medium to fine-grained organic and inorganic mixed sludge, with good compressibility and dewatering performance.

3. The physical, chemical, and biochemical mixed sludge generated from industrial wastewater treatment and discharged from concentration tanks, such as paper mills, printing and dyeing factories, washed cloth factories, meat processing plants, and breweries;

Sludge classification: It belongs to medium to fine-grained mixed sludge, with good dewatering performance for fibrous materials, and good compressibility and dewatering performance for other materials.

4. The physicochemical and biochemical mixed sludge generated from the treatment of wastewater in the chemical industry and discharged from the concentration tank, such as in petrochemical plants, organic chemical plants, etc;

Sludge classification: It belongs to fine-grained mixed sludge, with oil content and high viscosity. Its compressibility and dewatering performance are poor.

5. The physical and chemical fine-grained sludge generated by industrial wastewater treatment and discharged from concentration tanks, such as electroplating plants, circuit board plants, etc;

Sludge classification: It belongs to fine-grained inorganic sludge, with average compressibility and dewatering performance.

6. Medium sized sludge generated from industrial wastewater treatment, such as desulfurization and dust removal sludge from steel plants, salt sludge from alkali plants, red mud from aluminum plants, sludge from ceramic plants, sludge from color tube plants, lime neutralization and sedimentation sludge, etc;

Sludge classification: Belongs to medium particle size hydrophobic inorganic sludge, with good compressibility and dewatering performance.

7. Coarse grained sludge generated from industrial wastewater treatment, such as tailings from coal washing plants and quartz slag from glass factories;