engineering recuitment KPSC Assistant Engineer Civil Mock Test 2020 Environmental Engineering Sewage Sewage Treatment
A volume of 50,000 m3 of wastewater is seeded in an activated treatment plant per day with the efficiency of 95% and effluent BOD as 350 mg/L. The concentration of mixed liquor suspended solids and waste sludge suspended solid is 3500 mg/L and 8700 mg/L. Hydraulic retention time (HRT) of the sludge in the aeration tank is 10 hrs, and quantity of waste sludge is 500 m3 per day when the concentration of suspended solids in the effluent is 50 mg/L. The food to micro-organism ratio and sludge age respectively will be
1
4.8 kg/kg/d & 10.68 days
2
0.2778 kg/kg/d & 11.54 days
3
0.30 kg/d & 12.22 days
4
1.65 kg/kg/d & 12.22 days