Question

About wastewater treatment:

A. Explain the primary, secondary and tertiary WWTPs (Wastewater Treatment Plants). You can use diagrams and explain them.

b. In addition to the WWTPs, mention and explain two alternatives for treating wastewater.

Answer 1

Waste water treatment is the phenomenon which is used for the removalvof contamination from the sewage and thus convert into the effluent, so that it can be reused directly.
Primary Waste Water Treatment: In this stage of treatment, the wastewater is put in the settling tank, so that the heavier solid waste sinks to the bottom of tank. Whereas, lighter waste floats on the surface. The settled material are held back whereas the left over liquid is discharged to more wastewater treatment that is the phase of secondary treatment.
Secondary treatment is done on the deeper level. It is done by
1. BioFiltration- In this, sand filters are used so that additional sediments gets removed.
2. Aeration- In the huge aeration tank, air is pumped so that waste water gets mix with sludge which helps to grow bacteria that utilise oxygen.
Tertiary Treatment- This stage removes almost 99% of the impurities which are present in waste water. This process is quite expensive because it needs well trained, equipment which are specialised whicj are not readily available.

The alternative way to treat wastewater is to sprinkle the wastewater on the bed of sand so that water filters. Further, this water is put into contact with microbes and oxygen which together helps to breakdown the organic matter present in water.

stay safe?for any doubt ask in comments.