Question

A 2,250 m3/day extended aeration system is used to treat sewage from Taman Maju Jaya.
The average BOD influent of the sewage treatment plant is 250 mg/L and is reduced by
65% after the primary clarifier. It has two rectangular aeration tanks (working in parallel)
with a dimension of 4 m width, 6 m length and 3.5 m water depth. The aeration tank
maintains a biomass concentration of about 4000 mg/L.
(i) Determine the food-to-microorganism ratio of the aeration tank
(ii) Calculate the volumetric loading of the aeration tank
(iii) What is the most practical way to reduce or increase the food-to-microorganism ratio
of the system? Justify your answer
(iv) Determine the BOD effluent from the system

Answer 1