Write a short note on sewage management in cities.

Explanation

i. In cities, sewage is carried to the processing unit and acted upon by microbial processes.
ii. Microbes capable of decomposing any compound as well s destroying pathagens like those which cause cholera, typhoid, etc., are mixed with sewage.
iii. Carbon compounds present in swage are decomposed and gases like methane and `CO_(2)` are released.
iv. Xenobiotic chemicals present in sewage are decomposed by phenol-oxidizing bacteria.
v. The sludge that settles down can be used as fertilizer and the water released after microbial treatment can be treated and reused for different purposes, as it is environmentally safe.