Assume that due to dwindling supplies of crude oil and natural gas, the US embarks on a plan to implement the "hydrogen economy" for which hydrogen will be generated by electrolysis of water. The source of electricity is from photovoltaic (PV) conversion of sunlight in the southwestern US. (a) Assume that a flat pla ...continues
Environmental chemistry - change in carbon
The total mass of Carbon contained in fossil-fuels that were burned in the world from the year 1750 to the year 2000 was estimated to be 2.7 x E14 kg C. The amound of carbon released as CO2 from agricultural expansion and deforestation over this period is estimated to be 1.3 x E14 kg C. The concentration of CO2 in the atmosphere ...continues
Environmental chemistry question - short
Assume that waste will contain 295.0 mg/L of biodegradable CH2O and will be processed through a 200000.0 L/day sewage treatment plant which converts 40% of the waste to CO2 and H2O. Calculate the volume (in Liters) of air (at 25 degrees C, 1 atm) required for this conversion. Assume that the O2 is transferred to the water with 2 ...continues
Calculation of calcium carbonate dissolved per liter.
The average pH of precipitation in rural areas is 5.80. Assuming that the pH is controlled by the carbonate system, i.e., no anthropogenic acid gases are present in the atmosphere, calculate the amount of calcium carbonate (mg) dissolved per liter of rainwater. pKa1=6.33, KCO2=3.388e-02 Hint: pCO2=3.162e-04
How much Fe++ (in moles per litre) could be present in water which contains 1.4 x 1e-02 M HCO3- (bicarbonate) without causing the precipitation of FeCO3 (Ksp=10^(-10.7)) Hint: carbonate eq.
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 i ...continues
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 ...continues
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 ...continues
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 ...continues
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 ...continues
