What is removed by sedimentation in the sewage treatment process?

In $STPs$,what is the effluent water?

Secondary sewage treatment is mainly a

What is primary sludge?

In a sewage treatment plant,primary treatment is

Given below are two statements about sewage. Based on them,select the correct option given below.
Statement $I$: The sediment in the settling tank is called floc.
Statement $II$: Sewage is first passed in the grit chamber,then it is screened.