What is the key difference between primary and secondary sewage treatment?
Sewage treatment is a physical (mechanical) or biological or chemical process of removing contaminants from wastewater which contain household sewage, industrial sewage in the water. After sewage treatment the water is safe enough for release into the environment. A by-product of sewage treatment may be a semi-solid waste or slurry, called sewage sludge. The sludge has got to undergo further treatment before being suitable for disposal or application to land. The sewage treatment mainly is of two types – primary sewage treatment and secondary sewage treatment, which are discussed above.
