In cities sewage needs to be carried to processing unit and acted upon by microbial process. Microbes which can decompose any compound as well as destroy the pathogens of cholera , typhoid are mixed with sewage . They release methane and carbondioxide by decomposition of the carbon compounds present in sewage. Phenoi oxidising bacteria decompose the xenobiotic chemicals present in sewage.
Give a heading to the paragraph .

Explanation

Sewage Management in cities .