(i) and (ii)
(ii) and (iii)
(i) and (iv)
(ii) and (iv)
removal of turbidity
removal of hardness
killing of disease bacteria
complete sterilisation
only (i)
both (i) and (ii)
both (i) and (iii)
only (iii)
applied chlorine
residual chlorine
sum of applied and residual chlorine
difference of applied and residual chlorine
prechlorination
post chlorination
super chlorination
break point chlorination