Aircraft deicing fluid is primarily propylene glycol (PG, formula C3H8O2) miscible in water. At Denver International Airport in a typical winter, approximately 4,000 m3 of deicing fluid is used that contains 50% PG. a. Assuming PG is fully miscible in water, highly biodegradable, and has a similar density to water, what is the COD mass equivalent of this amount of deicing fluid, in kg/yk? b. Assuming cells growing on PG produce 0.4 g-cells (dry weight)/g-PG, write the COD-based stoichiometry for aerobic biodegradation of PG with cell growth and the COD-based yield factor, if the COD equivalent of PG = 1.684 g-COD/g-PG. = C. What is the actual oxygen requirement for complete (100%) biodegradation of the influent PG including cell growth (kg/yr)? d. DIA would like to send their waste deicing fluid, which is 25% of the volume of deicing fluid used in deicing aircraft, to the Denver Metro Wastewater Reclamation plant for aerobic biological treatment. DIA is already paying to send sanitary waste to the Metro plant but will be assessed an extra charge based on the cost of electricity for aeration and for excess biosolids disposal. Assume the PG composition of the deicing wastewater is the same as the original deicing fluid (50% PG). If the cost of supplying oxygen through diffused air aeration system is 0.3 kwh/kg-O2 at a cost of $0.10/kwh, and the cost of treating the excess biosolids produced in PG degradation is $800/metric ton of excess cells grown (1 MT = 1,000 kg), how much should the Denver Metro plant operators charge DIA for treatment of one winter's deicing wastewater? = Aircraft deicing fluid is primarily propylene glycol (PG, formula C3H8O2) miscible in water. At Denver International Airport in a typical winter, approximately 4,000 m3 of deicing fluid is used that contains 50% PG. a. Assuming PG is fully miscible in water, highly biodegradable, and has a similar density to water, what is the COD mass equivalent of this amount of deicing fluid, in kg/yk? b. Assuming cells growing on PG produce 0.4 g-cells (dry weight)/g-PG, write the COD-based stoichiometry for aerobic biodegradation of PG with cell growth and the COD-based yield factor, if the COD equivalent of PG = 1.684 g-COD/g-PG. = C. What is the actual oxygen requirement for complete (100%) biodegradation of the influent PG including cell growth (kg/yr)? d. DIA would like to send their waste deicing fluid, which is 25% of the volume of deicing fluid used in deicing aircraft, to the Denver Metro Wastewater Reclamation plant for aerobic biological treatment. DIA is already paying to send sanitary waste to the Metro plant but will be assessed an extra charge based on the cost of electricity for aeration and for excess biosolids disposal. Assume the PG composition of the deicing wastewater is the same as the original deicing fluid (50% PG). If the cost of supplying oxygen through diffused air aeration system is 0.3 kwh/kg-O2 at a cost of $0.10/kwh, and the cost of treating the excess biosolids produced in PG degradation is $800/metric ton of excess cells grown (1 MT = 1,000 kg), how much should the Denver Metro plant operators charge DIA for treatment of one winter's deicing wastewater? =
