Sludge Treatment And Handling
Sludge also referred as residual solids is a byproduct of waste water treatment either from physical treatment, chemical treatment and biological treatment. Initial sludge includes almost 3 to 6 % of residual solids. The ultimate aim of sludge treatment is to reduce the volume of sludge generated before the disposal of sludge. The sludge treatment utilizes the gas from anaerobic digestion which is a part of sludge treatment process. On the other hand sludge shall be utilized to condition the soil which is better than sludge disposal.
The sludge with less residual solids can be easily pumped with force mains. 2 % of residual solids in sludge have the characteristics of hydraulics. If the percentage of residual solids increases then the frictional loss also increases. The frictional loss and head loss increases as the temperature decreases. The ways by which sludge can be pumped out is as follows.
The volume of sludge reduces when thickened. Activated sludge tank can also reduce the volume of sludge. It can be continuous process or batch process. Types of thickeners are as follows.