the oxidation of Fe* by oxygen can be described by a rate expression of the form:...

 

Transcribed Image Text:

the oxidation of Fe* by oxygen can be described by a rate expression of the form: -k ep.+ CO COH where khas a value of 1.6 102 (L/mg O)(L/mol OH-) min- at 10C. The characteristics of a landfill leachate stream are presented below. In a proposed treatment system, the pH will be fixed at 7.5. Under these conditions, the rate expression describing BOD usage can be represented as follows: T BOD - (0.2 d-) CHOD CO 10+ 00 where COD and co, are both in milligram per liter. Henry's constant (Hpm) for O in the leachate at the temperature of interest is 625 atm/(mol/L). QL CFe+ 1150 m/d; c BOD 12,000 mg/L; 435 mg/L; co = 0 mg/L (a) Determine the fraction of the Fe+ that would be oxidized if the leachate were treated by diffused aeration in a CFSTR with a 1-h hydraulic detention time, if Ka = 10h-. Compare the magnitudes of the various terms in the mass balance on O in the reactor. (b) Determine the detention time that would be required to achieve 99% oxidation of the iron. Does the presence of the degradable organic matter have a large effect on the result? (c) Determine the detention time that would be required to achieve 50% removal of the BOD. the oxidation of Fe* by oxygen can be described by a rate expression of the form: -k ep.+ CO COH where khas a value of 1.6 102 (L/mg O)(L/mol OH-) min- at 10C. The characteristics of a landfill leachate stream are presented below. In a proposed treatment system, the pH will be fixed at 7.5. Under these conditions, the rate expression describing BOD usage can be represented as follows: T BOD - (0.2 d-) CHOD CO 10+ 00 where COD and co, are both in milligram per liter. Henry's constant (Hpm) for O in the leachate at the temperature of interest is 625 atm/(mol/L). QL CFe+ 1150 m/d; c BOD 12,000 mg/L; 435 mg/L; co = 0 mg/L (a) Determine the fraction of the Fe+ that would be oxidized if the leachate were treated by diffused aeration in a CFSTR with a 1-h hydraulic detention time, if Ka = 10h-. Compare the magnitudes of the various terms in the mass balance on O in the reactor. (b) Determine the detention time that would be required to achieve 99% oxidation of the iron. Does the presence of the degradable organic matter have a large effect on the result? (c) Determine the detention time that would be required to achieve 50% removal of the BOD.