ABSTRACT
Q29.1 The carriers in the reactor are initially colonized at a density (X0) of 4 g of dry biomass/m2 of carrier surface. The biolm density (X, g of dry biomass/m2 of carrier surface) increases linearly with time (T, days of reactor operation) as follows:
X = X0 + (0.72 × T)
The following information is also provided: Qm = 0.15 g of COD consumed/m2 of carrier surface ⋅ hr Hopt = 100 μm k = 0.2 The density of wet biomass (d) = 1.04 g/cm3. The content of water in an intact microbial cell (W) = 75% by weight of
the cell
1. Calculate the biolm thickness after 50 days of reactor operation. 2. Calculate the specic biodegradation activity of the microbial biomass after
50 days of reactor operation. 3. The reactor must cease operation and the excess biomass must be washed
off the carriers when the specic biodegradation activity of the biomass decreases to below 30% of its maximum value. When must the reactor be stopped for backwashing to clean the carrier surfaces?
