Home > Browse > Green Philosophy > Sewage Treatment
Sewage generated at various locations of the hotel premises is taken to the plant via a pumping station. It is initially admitted to the equalization tank and a bar screen installed at the entrance to the equalization tank removes any undesirable (inorganic) solids in sewage. The sewage is equalized and homogenized within the equalization tank, helping to minimize the load variations to the post treatment stages.
Sewage from the equalization tank is pumped to a flow divider which divides the flow to the sewage treatment plant (rotating immersion disk) and to the aeration system. Out of the total estimated sewage generation (225m3/day), 110m3 will be sent though the RBC to the RID system and 115m3 will be sent through the aeration system.
Two aeration tanks are fed in parallel for the removal of the pollution load of the sewage. Submersible aerators provide necessary oxygen for bacteria that consume pollutants (organic matter). Aeration also helps to maintain bacteria in suspension. The reaction which takes place in the aeration tank can be illustrated as follows:
Organic + Oxygen + Bacteria CO2 + NH3 + Other Products + New cells + energy
Aeration tanks are sized so that sewage entering the tank will be retained approximately 24 hours within the tank. The required load reduction in the pollutant will occur during this period, resulting in acceptable treated water.
The separation of aeration product (mixed liquor suspended solids) from treated water takes place in a clarifier tank. The product that is heavier than water will settle to the bottom of the clarifier tank. The settled particles (sludge) will be recycled to the aeration tank to maintain bacteria population (MLSS). In the aeration tank, the excess sludge formed will be diverted to sand drying beds.
Two gravity sand beds fed in parallel are incorporated in the plant for further polishing of treated water by removing suspended particles, if any remain. Filtrate from the sand bed is disinfected and diverted to treated water tanks for gardening.
 |
 |
 |
 |
 |
 |
|
|
 |
|
||
 |
 |
|
|
 |
 |
|
|
 |
 |
 |
|