In: Civil Engineering
The Lolla Hart hospital has a small activated sludge plant to treat its wastewater. The average daily hospital discharge is 1,500 L per day per bed, and the average soluble BOD5 after primary settling is 500 mg/L. Their permit dictates that the effluent BOD5 and TSS cannot exceed 30 and 20 mg/L, respectively, on an annual basis. Assume the MLVSS concentration in the aeration basin will be maintained at 3,000 mg/L. Also, assume that the concentration of BOD5 of the suspended solids is equal to 60% of the suspended solids concentration. The biokinetic coefficients were measured and determined to be:
Ks=70 mg/L BOD5
um=2.5 day-1
kd = 0.06 day-1
Y = 0.6 mg VSS/mg BOD5 removed
Find:
SRT in days
The Aeration basin volume (L)
The Aeration period (days)
The kg of secondary solids wasted each day