Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C, but the laboratory attendant did not note which was which. The BOD values of the three samples A, B and C were recorded as 20mg/L, 8mg/L and 400mg/L, respectively. Which sample of the water is most polluted? Can you assign the correct label to each assuming the river water is relatively clean?

Three water samples namely river water, untreated sewage water and secondary effluent discharge from a sewage treatment plant were subjected to BOD test. The samples were labelled A,B and C. but the laboratory attened did not note, which was which . The BOD values of the three samples A,B and C were recorded as 20 mg/L , 8 mg/L and 400 mg/L, respectively. which sample of the water is most polluted ? can you assign the correct label to each , assuming the river water is relatively clean

When domestic sewage mixes with river water

When domestic sewage mixes with river water

A water sample is said to contain permanent hardness if water contains

The absorption spectra of three samples A,B,C is given:

During the treatment of sewage water, the chemical process is carried out in which step of water treatment?

Biochemical oxygen demand (BOD) in a river water

Biochemical oxygeb demand (BOD) in a river water

Fishes die in water bodies polluted by sewage due to :

Which of the following ions will cause hardness in water sample?