Question

When small amounts of iron and manganese are present in water, they are removed by ____________

(a) Aeration

(b) Coagulation

(c) Manganese zeolite

(d) Filtration

This question was posed to me in quiz.

Origin of the question is Removal of Iron, Manganese, Colour, Odour and Taste in chapter Miscellaneous Treatment Methods of Environmental Engineering

Answer 1

The correct choice is (c) Manganese zeolite

The explanation is: When small amounts of iron and manganese are present in water, they are removed by manganese zeolite where iron and manganese are oxidized to insoluble hydrated oxides which are removed by filtration action of zeolite bed.