Sewage is actually the wastewater that is released from houses, hospitals, industries, offices and other sources. It also includes the rainwater that runs down the streets in a storm. The water that washes off the roads and rooftops contains many harmful substances. Sewage is the liquid waste. Wastewater has dissolved and suspended impurities in it. These impurities are known as contaminants.
The names are –
→ x is wastewater or sewage.
→ (a) is nitrogen or phosphorus.
→ (b) is Vibrio coma or Salmonella typhi.