Environmental Issues – Solutions
1. What are the various constituents of domestic sewage? Discuss the effects of sewage discharge on a river?
The wastes resulting from our household activities are called domestic sewage. It includes food wastes (organic), paper, plastics, cloth etc.
There are three constituents of domestic sewage.
- Suspended solids like slit, clay and sand.
- Colloidal materials like fecal matter, paper and cloth fibers, microbes.
- Dissolved materials eg. Phosphates, nitrates, sodium, calcium, ammonia etc.
The organic content of the sewage, when discharged into a river, is responsible for the microbial growth that utilizes the dissolved oxygen resulting into higher BOD (Biological Oxygen Demand).