Question

screening coagulation are preliminary treatment process.

true
false​

Answer 1

screening coagulation are preliminary treatment process.

screening coagulation are preliminary treatment process. - True .

• They both are preliminary treatment process .They use to remove dirt , sand and small particles and pathogens through this means.

• Screening used to retain solids found in the influent wastewater to the treatment plant like sand particles ,rock and sand . It's main purpose is to remove solid material .It is Physical treatment process .

• Coagulation is a pre-treatment through which pathogen are reduced typically >99% (high).

• Coagulation is done for sedimanting the particles at the bottom ,which afterwards can be filter out .It is done by adding aluminium salts ,which are called coagulants , they have positive charge so it will neutralise the negative charge particles and form a gelatinous mass, large enough to settle or be trapped in the filter.