Large quantity of sewage is generated every day in cities and towns, Which is treated in Sewage Treatment Plants (STPs) to make it less polluted. Given below is the flow diagram of one of the stages of STP.
Observe the given flow diagram and answer the questions accordigly.

Write the technical term used for the sediment formed. MEntion its significance.

Large quantity of sewage is generated every day in cities and towns, Which is treated in Sewage Treatment Plants (STPs) to make it less polluted. Given below is the flow diagram of one of the stages of STP. Observe the given flow diagram and answer the questions accordigly. Why is primary effluent passed into large aeration tanks?

Large quantity of sewage is generated every day in cities and towns, Which is treated in Sewage Treatment Plants (STPs) to make it less polluted. Given below is the flow diagram of one of the stages of STP. Observe the given flow diagram and answer the questions accordigly. Explain the final step that results in the formation of biogas in the large tank before the treated effluent is released into waterbodies.