No description available.

No description available.

No description available.

No description available.

M. S.

This study involved the use of soil and suspended growth microcosms to study the variation in groundwater denitrification rates using different substrates. Two gaseous substrates, carbon monoxide and methane, were studied and compared to a common liquid substrate, methanol. Denitrification with carbon monoxide as a substrate was achieved using an acclimated seed of mixed activated sludge and anaerobic digester sludge. Kinetic studies of denitrification using carbon monoxide suggested a strong substrate inhibition effect. The observed maximum denitrification velocity of 0.026 mg N/d-mg VSS occurred at a carbon monoxide partial pressure of 0.10 atmospheres (2.8 mg/ℓ). At higher carbon monoxide partial pressures, denitrification velocities decreased. The denitrification velocities at various carbon monoxide concentrations were described by a modified form of the Haldane substrate inhibition model. The biomass yield using carbon monoxide was 1.1 mg VSS/mg VSS, the maximum specific growth rate was 0.03 mg VSS/d-mg VSS, and the half velocity constant was 26 mg-N/ℓ. Denitrification rates using carbon monoxide as a substrate were much slower than those obtained using methanol, and the cost of carbon monoxide was much higher. Denitrification occurred readily, when methanol was provided as a substrate, in microcosms containing either a clay soil, a sandy soil, or activated sludge. Under the conditions of this study, denitrification was not achieved in clay soil or sandy soil microcosms using methane or carbon monoxide as substrates. Denitrification was not achieved using methane as a substrate with an activated sludge seed. / Ph. D.

No description available.

A bench scale laboratory ozonator was constructed and determined to produce 27 mg O3/hr. A contacting system and experimental procedure was developed to approximate a mass balance of 0, 1, 2, 4, 8 and 16 ppm were applied to raw and magnesium treated water from Lake Washington which is the potable water source for Melbourne, Florida. The effect of ozone on trihalomethane precursors was studied by comparing THM formation at 1, 24, 48, 72, and 96 hours following chlorination. The concentrations of each specie, chloroform, bromodichloromethane, dibromochlormethane and bromoform are reported. The highest 96 hour TTHM concentrations reported were 2773 ppb for the raw and 1205 ppb for the treated water. Chloroform was found to be the major specie of the THM's, averaging 80%. Ozone was found to reduce color of the raw and treated Lake Washington water. Ozone was shown to neither increase nor decrease TTHM concentrations with utilized ozone dosed up to 10.6 ppm. Increasing utilization of ozone was found to increase CHClBr2 concentrations in the raw and coagulated water. Regression equations at the 0.01 level of significance were developed for CHClBr2 formation and utilized ozone, color reduction and utilized ozone, TTHM formation and reaction time, and finally ozone production and time.

This research investigated the relationships between molecular size and the TOC, TTHM, acid strength and color concentrations present in raw and coagulated water from Lake Washington. Three separate coagulants were utilized for investigation. There were: Al, Fe and Mg. Results indicated that the majority of the TOC, color and TTHM precursors were in the colloidal size range and removed by coagulation. The remaining TTHM precursors are mostly molecular and require a process other than coagulation for removal from the potable water before environmental standards are met.

No description available.