INVESTIGADORES
MARTIN Carlos Alberto
congresos y reuniones científicas
Título:
Oxygen Effects in Photocatalytic Reactions: Application to the Degradation of Dichloroacetic Acid
Autor/es:
C. ZALAZAR, C. MARTÍN Y A. CASSANO
Lugar:
San Diego, USA
Reunión:
Congreso; AOT´s-10 Advanced Oxidation Technologies For Water and Air Remediation; 2004
Resumen:
The effect of oxygen concentration on the photocatalytic oxidation of low
concentration, aqueous solutions of dichloroacetic acid (DCA) - a typical by product of
chlorine disinfection - was studied employing titanium dioxide and UV radiation. The study
aims at the development of an intrinsic and complete reaction kinetics (apt for scaling-up
purposes) that will consider also the oxygen demand as one of the design variables,
particularly important for liquids having a very high COD.
Using the mass action law and the micro steady state approximation, a kinetic model
was developed starting from a complete reaction sequence based on the direct hole attack of
DCA and the participation of oxygen as the main electron acceptor. The obtained
representation gives reaction rates for the DCA and oxygen disappearance as well as chloride
ion formation. The model includes the local rate of photon absorption numerically obtained
employing the Discrete Ordinate Method.
The employed reactor (a cylinder with a volume of 110 cm3) irradiated from both sides
with tubular lamps and parabolic reflectors was part of a recycling system. Experiments were
conducted at different experimental conditions (DCA, catalyst and oxygen concentrations as
well as Incident Radiation were independent variables).
The mass balance for DCA degradation, chloride ion formation and oxygen
consumption was closed with very small error. Finally, using the kinetic model, the mass
balance for the recycling system and the experimental data, upon application of the
Levenberg-Marquardt optimization algorithm, the kinetic constants were obtained and then
experimental data were compared with theoretical predictions from the reactor-reaction
kinetic model obtaining very good agreement.
with tubular lamps and parabolic reflectors was part of a recycling system. Experiments were
conducted at different experimental conditions (DCA, catalyst and oxygen concentrations as
well as Incident Radiation were independent variables).
The mass balance for DCA degradation, chloride ion formation and oxygen
consumption was closed with very small error. Finally, using the kinetic model, the mass
balance for the recycling system and the experimental data, upon application of the
Levenberg-Marquardt optimization algorithm, the kinetic constants were obtained and then
experimental data were compared with theoretical predictions from the reactor-reaction
kinetic model obtaining very good agreement.
3) irradiated from both sides
with tubular lamps and parabolic reflectors was part of a recycling system. Experiments were
conducted at different experimental conditions (DCA, catalyst and oxygen concentrations as
well as Incident Radiation were independent variables).
The mass balance for DCA degradation, chloride ion formation and oxygen
consumption was closed with very small error. Finally, using the kinetic model, the mass
balance for the recycling system and the experimental data, upon application of the
Levenberg-Marquardt optimization algorithm, the kinetic constants were obtained and then
experimental data were compared with theoretical predictions from the reactor-reaction
kinetic model obtaining very good agreement.
concentration, aqueous solutions of dichloroacetic acid (DCA) - a typical by product of
chlorine disinfection - was studied employing titanium dioxide and UV radiation. The study
aims at the development of an intrinsic and complete reaction kinetics (apt for scaling-up
purposes) that will consider also the oxygen demand as one of the design variables,
particularly important for liquids having a very high COD.
Using the mass action law and the micro steady state approximation, a kinetic model
was developed starting from a complete reaction sequence based on the direct hole attack of
DCA and the participation of oxygen as the main electron acceptor. The obtained
representation gives reaction rates for the DCA and oxygen disappearance as well as chloride
ion formation. The model includes the local rate of photon absorption numerically obtained
employing the Discrete Ordinate Method.
The employed reactor (a cylinder with a volume of 110 cm3) irradiated from both sides
with tubular lamps and parabolic reflectors was part of a recycling system. Experiments were
conducted at different experimental conditions (DCA, catalyst and oxygen concentrations as
well as Incident Radiation were independent variables).
The mass balance for DCA degradation, chloride ion formation and oxygen
consumption was closed with very small error. Finally, using the kinetic model, the mass
balance for the recycling system and the experimental data, upon application of the
Levenberg-Marquardt optimization algorithm, the kinetic constants were obtained and then
experimental data were compared with theoretical predictions from the reactor-reaction
kinetic model obtaining very good agreement.
with tubular lamps and parabolic reflectors was part of a recycling system. Experiments were
conducted at different experimental conditions (DCA, catalyst and oxygen concentrations as
well as Incident Radiation were independent variables).
The mass balance for DCA degradation, chloride ion formation and oxygen
consumption was closed with very small error. Finally, using the kinetic model, the mass
balance for the recycling system and the experimental data, upon application of the
Levenberg-Marquardt optimization algorithm, the kinetic constants were obtained and then
experimental data were compared with theoretical predictions from the reactor-reaction
kinetic model obtaining very good agreement.
3) irradiated from both sides
with tubular lamps and parabolic reflectors was part of a recycling system. Experiments were
conducted at different experimental conditions (DCA, catalyst and oxygen concentrations as
well as Incident Radiation were independent variables).
The mass balance for DCA degradation, chloride ion formation and oxygen
consumption was closed with very small error. Finally, using the kinetic model, the mass
balance for the recycling system and the experimental data, upon application of the
Levenberg-Marquardt optimization algorithm, the kinetic constants were obtained and then
experimental data were compared with theoretical predictions from the reactor-reaction
kinetic model obtaining very good agreement.
concentration, aqueous solutions of dichloroacetic acid (DCA) - a typical by product of
chlorine disinfection - was studied employing titanium dioxide and UV radiation. The study
aims at the development of an intrinsic and complete reaction kinetics (apt for scaling-up
purposes) that will consider also the oxygen demand as one of the design variables,
particularly important for liquids having a very high COD.
Using the mass action law and the micro steady state approximation, a kinetic model
was developed starting from a complete reaction sequence based on the direct hole attack of
DCA and the participation of oxygen as the main electron acceptor. The obtained
representation gives reaction rates for the DCA and oxygen disappearance as well as chloride
ion formation. The model includes the local rate of photon absorption numerically obtained
employing the Discrete Ordinate Method.
The employed reactor (a cylinder with a volume of 110 cm3) irradiated from both sides
with tubular lamps and parabolic reflectors was part of a recycling system. Experiments were
conducted at different experimental conditions (DCA, catalyst and oxygen concentrations as
well as Incident Radiation were independent variables).
The mass balance for DCA degradation, chloride ion formation and oxygen
consumption was closed with very small error. Finally, using the kinetic model, the mass
balance for the recycling system and the experimental data, upon application of the
Levenberg-Marquardt optimization algorithm, the kinetic constants were obtained and then
experimental data were compared with theoretical predictions from the reactor-reaction
kinetic model obtaining very good agreement.
with tubular lamps and parabolic reflectors was part of a recycling system. Experiments were
conducted at different experimental conditions (DCA, catalyst and oxygen concentrations as
well as Incident Radiation were independent variables).
The mass balance for DCA degradation, chloride ion formation and oxygen
consumption was closed with very small error. Finally, using the kinetic model, the mass
balance for the recycling system and the experimental data, upon application of the
Levenberg-Marquardt optimization algorithm, the kinetic constants were obtained and then
experimental data were compared with theoretical predictions from the reactor-reaction
kinetic model obtaining very good agreement.
with tubular lamps and parabolic reflectors was part of a recycling system. Experiments were
conducted at different experimental conditions (DCA, catalyst and oxygen concentrations as
well as Incident Radiation were independent variables).
The mass balance for DCA degradation, chloride ion formation and oxygen
consumption was closed with very small error. Finally, using the kinetic model, the mass
balance for the recycling system and the experimental data, upon application of the
Levenberg-Marquardt optimization algorithm, the kinetic constants were obtained and then
experimental data were compared with theoretical predictions from the reactor-reaction
kinetic model obtaining very good agreement.