1. Is BOD5 value always assumed to be at 20 degree, even if the water temperature given is at different tempature, say 25 degree?
2. If inflow from primary settlement tank to aeration tank is Q, and recirculation rate R, the 2nd clarifier surface loading rate is Q/A or (1+R)Q/A? A is surface area of the clarifier tank. CERM is giving this value as (1+R)Q/A, while Metcalf Eddy Book is saying this value is Q/A. Which one is the one I should use for PE exam?
Thanks.
2. If inflow from primary settlement tank to aeration tank is Q, and recirculation rate R, the 2nd clarifier surface loading rate is Q/A or (1+R)Q/A? A is surface area of the clarifier tank. CERM is giving this value as (1+R)Q/A, while Metcalf Eddy Book is saying this value is Q/A. Which one is the one I should use for PE exam?
Thanks.