1. Water purification plant sludge

The sludge in the water purification plant is composed of the backwash drainage of the filter tank and the solids in the sludge discharged from the sedimentation tank or clarifier. The filter backwash sludge is mainly composed of suspended solids, clay, organic matter and chemical residues; the sedimentation tank sludge can be divided into two types: lime softened sludge and chemical flocculation sedimentation sludge. The softened sludge is mainly produced in the raw water. In the softening process, the main components are calcium carbonate, magnesium hydroxide, organic matter and excess softening reagent. Sedimentation tank sludge is the main object of sludge treatment in water purification plants.

2. Sewage plant sludge

Sewage plant sludge is the precipitation material produced in the process of wastewater treatment. It includes solid particles such as sediment, fibers, animal and plant residues mixed into domestic sewage and industrial and mining wastewater, as well as their coagulated flocs, various colloids, organic matter and The integrated solid matter of adsorbed metal elements, microorganisms, germs, eggs and other substances, in short, it is the solid part of sewage. According to different treatment methods and separation processes, it can be divided into sedimentation sludge (including physical sedimentation sludge, coagulation sedimentation sludge, chemical sedimentation sludge) and biological treatment sludge (including excess sludge, biofilm sludge).