Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

→ We know that large quantities of waste water are generated everyday in cities and towns. A major component of this waste water is human excreta. This municipal waste water is also called sewage.
→ It contains large amounts of organic matter and microbes, many of which are pathogenic.
→ This cannot be discharged into natural water bodies like rivers and streams directly.
→ Before disposal, hence, sewage is treated in Sewage Treatment Plant (STPs) to make it less polluting.
→ The pollutants and pathogens in sewage cause water-borne animal disease like typhoid, cholera etc.