An industry discharges PCE (tetrachloroethene, tetratchloroethylene, or perchloroethylene) into a small, well-mixed lake. The influent concentration is 0.4mg/L and the hydraulic residence time of the lake is 5days.
A. What is the concentration of PCE in the lake (at steady state) if PCE degradesin the lake with a first-order rateconstant k= 0.5d-1?
B. A DWTP takes water from the lake. The oral RfD for PCE is 0.01 mg/kg-d (text,Table 4.11). Is the averagedaily dose from consuming 2 L/d of water from the DWTP greaterthan the RfD? Assume a 70 kg body weightand no removal in the DWTP.
C. The bioconcentration factor for PCE is 31 L/kg (text, Table 4.12). Is theaverage daily dosefrom eating 60 gof fish per day caught from this lakegreater than the RfD? Assume a 70 kg body weight