Question

Why should oils and fats be not released in the drain? Explain.

Answer 1

Sewage can be treated or created by a network of pipes and pump stations to a municipal treatment plant. Through sewage wastewater is treated in three phases that are primary, secondary and tertiary. Sewage is created by residential and industrial establishments. It includes household waste liquid from toilets, baths, showers, kitchens, sinks etc.

Complete answer:
Because of the release of oils and fats in drains it hardens the soil in sewage pipes and blocks them. Fat blocks the drain by clogging the holes of the soil . it does not allow the movement of water it becomes stop to flow.Fat block porosity of soil in an open drain which affects on the filtering efficiency of water. so oils and fats should not be released in the drain.

Additional information:
Some of the steps are involved in the purification of water that are as follows:
(i) Primarily all the solid impurities like stones, plastic bags, cans, etc. are to be removed. It is done through passing the water from bar screens.
(ii) After it water is taken to a grit and sand removal tank where impurities are removed by sedimentation.
(iii) All the solid impurities and faeces are collected at the bottom of the water. These impurities collected are called sludge.
(iv) Clarified water is cleaned of other impurities by the aerator. All disease-causing bacteria are removed by chlorination.

Note: When water undergoes clarification to remove suspended solids and solid particles that is called clarified water. The clarification of water is used in the pre-treatment of drinking water, prior to further purification, and the treatment of municipal wastewater and industrial effluent.