|
|
|
Primary
Treatment - This removes suspended solids in settling tanks or basins. Solids are drawn off. Raw sewage is piped into huge open tanks where it is screened to remove solid fraction. This solid material is then subjected to anaerobic digestion in landfill or composting.
The liquid portion is then passed into sludge tanks for further treatment. Flocculating materials as aluminium or iron sulphate are also added to raw sewage to trap microbes and debris to the bottom as in the sedimentation process of water purification. These materials are added to sludge tanks also.
|
|
| |
|
|
| |
|
|
|
