|Installation Type||Completes Civil work with Installation|
|I deal in||New Only|
Effluent can be treated in a number of different ways depending on the level of treatment required. These levels are known as preliminary, primary, secondary and tertiary (or advanced). The mechanism for treatment is divided into three categories: Physical, chemical and biological.
Units in Preliminary Treatment
It consists of temporarily holding the sewage in an inert basin where heavy solids can settle to the bottom where oil, grease and lighter solids float to the surface. The settled material go for sludge treatment in sludge digesters and floating materials are skimmed off and the remaining liquid is passes to secondary treatment. At this stage, over 70% of the suspended solids and 40% of the BOD is removed from the effluent.
Units in Primary Treatment
It is a biological treatment of effluent removes dissolved and suspended organic (bio-degradable) matters by consuming food and convert it into new cell mass, energy and CO2.
Most common micro-organisms are bacteria (aerobic or anaerobic), protozoa and rotifers, least common fungi and algae. This treatment removes almost 70- 90% of BOD and 80- 90% of dissolved solids from effluent. The under flow from the clarifier and the secondary clarifier having a sludge consistency of around 1-1.5% is pumped into the centrifuge for dewatering. The dewatered sludge is then disposed off suitably while the concentrate is taken back to equalization tank.