oxidation

dehydration

reduction

alkalinization

starch iodide method

orthotolidine method

both starch iodide method and orthotolidine method

none of the above

ultra violet rays treatment

lime treatment

by using potassium permanganate

chlorination

less than 1.0 m/sec

1.0 m/sec to 1.2 m/sec

1.5 m/sec to 2.0 m/sec

3.0 m/sec to 3.5 m/sec