Environmental chemistry - Hydrogen and electricity

Assume that due to dwindling supplies of crude oil and natural gas, the US embarks on a plan to implement a "hydrogen economy" for which hydrogen will be generated by water electrolysis. The source of electricity will be from photovoltaic (PV) conversion of sunlight in the southwestern US. (a) Assume that a flatplate PV system is used, with a solar conversion efficiency of 10 percent and a hydrogen production efficiency of 60 percent. Assume the average annual insolation in the southwest is 270 watts per square meter. Calculate the annual electrical energy produced in kJ/sq. meter. Calculate the weight of hydrogen (kg/sq. meter) produced per year. (b) The US consumed 40 EJ of petroleum i... click for more

Assistance with finding the ultimate carbonaceous BOD, reaction rate coefficient, and BOD5 at 15 degrees Centigrade given a BOD5 of 150 mg/L at 20 degrees Centigrade and reaction rate k at that temperature of 0.23/day.

Info: BOD: Biochemical Oxygen Demand BOD5 is the total amount of oxygen consumed by microorganisms during the first five days of biodegradation BOD5 = (DOi – Dof)/(P) this is the five-day BOD of a diluted sample Where DOi = the initial dissolved oxygen (DO) of the diluted wastewater DOf = the final DO of the diluted wastewater, 5 days later P = the dilution fraction = (volume of wastewater)/(volume of wastewater plus dilution water) A standard BOD bottle holds 300 mL, so P is just the volume of wastewater divided by 300 mL 5.12) Some wastewater has a BOD5 of 150 mg/L at 20 degrees Centigrade. The reaction rate k at that temperature has been de... click for more

Biochemical Oxygen Demand

Info: BOD: Biochemical Oxygen Demand BOD5 is the total amount of oxygen consumed by microorganisms during the first five days of biodegradation BOD5 = (DOi – Dof)/(P) this is the five-day BOD of a diluted sample Where DOi = the initial dissolved oxygen (DO) of the diluted wastewater DOf = the final DO of the diluted wastewater, 5 days later P = the dilution fraction = (volume of wastewater)/(volume of wastewater plus dilution water) A standard BOD bottle holds 300 mL, so P is just the volume of wastewater divided by 300 mL 5.23) A single source of BOD causes an oxygen sag curve with a minimum downstream DO equal to 6.0 mg/L. If the BOD of the ... click for more

Dissolved oxygen problem/ environmental engineering

Info: BOD: Biochemical Oxygen Demand BOD5 is the total amount of oxygen consumed by microorganisms during the first five days of biodegradation BOD5 = (DOi – Dof)/(P) this is the five-day BOD of a diluted sample Where DOi = the initial dissolved oxygen (DO) of the diluted wastewater DOf = the final DO of the diluted wastewater, 5 days later P = the dilution fraction = (volume of wastewater)/(volume of wastewater plus dilution water) A standard BOD bottle holds 300 mL, so P is just the volume of wastewater divided by 300 mL 5.31) For the following waste and river characteristics just upstream from the outfall, find the minimum downstream DO tha... click for more

Waste water mass balance problem

Info: BOD: Biochemical Oxygen Demand BOD5 is the total amount of oxygen consumed by microorganisms during the first five days of biodegradation BOD5 = (DOi – Dof)/(P) this is the five-day BOD of a diluted sample Where DOi = the initial dissolved oxygen (DO) of the diluted wastewater DOf = the final DO of the diluted wastewater, 5 days later P = the dilution fraction = (volume of wastewater)/(volume of wastewater plus dilution water) A standard BOD bottle holds 300 mL, so P is just the volume of wastewater divided by 300 mL 5.36) Consider a lake with 100 X 10^6 m^2 of surface area for which the only source of phosphorus is the effluent from a w... click for more