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Abstract :
[en] Natural water is a resource threatened by its increasing use in the industrial,
agricultural, household fields, etc. Solutions like (waste)water treatment plants are important to purify it and obtain a
drinkable water. From all the pollutants possibly detected in the water, this study focuses on organic micropollutants
passing through the conventional physicochemical and biological processes applied in the wastewater treatment plants
due to their high chemical resistance and low concentration level. In addition, numerous micropollutants must exhibit toxic
effects for the living beings like endocrine disruptor, carcinogenic effect, etc.
For that purpose, advanced oxidation process (AOP) were developed and have demonstrated high efficiency against
more concentrated organic compounds (mg/L). Among the AOPs, this paper discusses about the photocatalysis which is
the activation by the light of a catalyst, like the well-known TiO2. Comparatively to the others AOPs, the advantages are
non-use of dangerous chemical products like H2O2 and consequently avoid the extra-cost due to a special storage, the
low energy consumption in comparison to the sonolysis and photolysis processes.
The main goal of the project is to design an innovative photoreactor from which key parameters will be determined to
allow the scaling-up of the process at an industrial scale. The laboratory device is based on a commercial UV-sterilisation
unit in which an efficient and rugged photocatalytic substrate will be adequately incorporated. Currently, the researches
are focused on the development of the photocatalytic substrate.
Water purification by photocatalysis has often been studied using suspensions of TiO2 in heated water, this approach
required an expensive recovery step to remove dispersed powders. This problem is avoided by coating the photocatalyst
on a quartz substrate. Prior to the geometry selection, the composition of a colloidal suspension, based on a study [1],
was optimized to improve the stability of the coating while keeping good photocatalytic performances. The evaluation was
performed by nanoscratch and hydraulic tests.
In addition, the very low concentration levels (μg/L) of pollutants required the optimisation of the adsorption property that
can be applied before the photodegradation and promote the overall efficiency of the process. In that way, additives are
tested in adsorption assays. Preliminary results showed, in good agreement with the literature, a positive effect of the
active carbon.
Other characterisation technics like BET analysis, SEM analysis, transmission and profilometry tests are investigated.
Taking into account all the data, the coating with the most interesting properties will be selected and kinetics of
photodegradation will be determined in the second phase of the work for the design of the reactor.Natural water is a resource threatened by its increasing use in the industrial,
agricultural, household fields, etc. Solutions like (waste)water treatment plants are important to purify it and obtain a
drinkable water. From all the pollutants possibly detected in the water, this study focuses on organic micropollutants
passing through the conventional physicochemical and biological processes applied in the wastewater treatment plants
due to their high chemical resistance and low concentration level. In addition, numerous micropollutants must exhibit toxic
effects for the living beings like endocrine disruptor, carcinogenic effect, etc.
For that purpose, advanced oxidation process (AOP) were developed and have demonstrated high efficiency against
more concentrated organic compounds (mg/L). Among the AOPs, this paper discusses about the photocatalysis which is
the activation by the light of a catalyst, like the well-known TiO2. Comparatively to the others AOPs, the advantages are
non-use of dangerous chemical products like H2O2 and consequently avoid the extra-cost due to a special storage, the
low energy consumption in comparison to the sonolysis and photolysis processes.
The main goal of the project is to design an innovative photoreactor from which key parameters will be determined to
allow the scaling-up of the process at an industrial scale. The laboratory device is based on a commercial UV-sterilisation
unit in which an efficient and rugged photocatalytic substrate will be adequately incorporated. Currently, the researches
are focused on the development of the photocatalytic substrate.
Water purification by photocatalysis has often been studied using suspensions of TiO2 in heated water, this approach
required an expensive recovery step to remove dispersed powders. This problem is avoided by coating the photocatalyst
on a quartz substrate. Prior to the geometry selection, the composition of a colloidal suspension, based on a study [1],
was optimized to improve the stability of the coating while keeping good photocatalytic performances. The evaluation was
performed by nanoscratch and hydraulic tests.
In addition, the very low concentration levels (μg/L) of pollutants required the optimisation of the adsorption property that
can be applied before the photodegradation and promote the overall efficiency of the process. In that way, additives are
tested in adsorption assays. Preliminary results showed, in good agreement with the literature, a positive effect of the
active carbon.
Other characterisation technics like BET analysis, SEM analysis, transmission and profilometry tests are investigated.
Taking into account all the data, the coating with the most interesting properties will be selected and kinetics of
photodegradation will be determined in the second phase of the work for the design of the reactor.
