पानी में घुली गैसों की अशुद्धियों को मुख्य रूप से किस उपचार प्रक्रिया द्वारा दूर किया जाता है?

Which treatment process may help in removing colour, odour, turbidity and some pathogenic bacteria from water?

Which coagulant reagents are commonly added during water treatment to neutralize and settle suspended colloidal particles?