Determine the size of a occulation tank (single CM FR) for a 10 MLD (million litres per day) water treatment plant if raw water contains 10,000 particlest, which can be approximated as spherical particles with a diameter of 100 pm having an empirical aggregation constant of 1.2. Flocculation process should yield 90% reduction in the number of particles using a mean velocity gradient of 40 5'1