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Immobilized photosensitizers as new materials in water treatment
Coordinator - José Cavaleiro (com a participação de Adelaide Almeida)
Programme - POCTI
Execution dates - 2005-09-01 - 0000-00-00 (428 Months)
Funding Entity - FCT
Funding for CESAM - 100000 €
Total Funding - 100000 €
Proponent Institution -

It is well known that the high growth of the population in urban areas increases the amount of wastewater to treat. The lack of new technologies for the wastewater treatment induces the reduction of water resources, and increases the environmental pollution. The microorganisms elimination that represent a high danger level for health public could be reached using UV light, Ozone and chlorine. These solutions have not been yet implemented due to environmental and economical imperatives, however, it is urgent to develop new technologies in the wastewater treatment.
The possibility to use photosensitizers bound to insoluble supports can be an interesting approach to kill pathogenic microorganisms present in wastewaters.
In this project it is proposed to carry out studies leading to new photosensitizers immobilized in carrier materials. The final materials should have adequate photophysical and chemical properties to treat waste effluents.
This work will involve the preparation of several meso-substituted porphyrin derivatives; one of the meso-aryl groups is adequately functionalised for giving the possibility to promote a covalent coupling to solid supports. The reaction conditions will be studied in order to reach the best synthetic procedures.
The immobilization of sensitizers requires specific surfaces on the supported materials. Several silicate based materials covered by a functionalized hybrid interlayer will be prepared. Then, the porphyrin derivatives will be immobilized on the surface of silicate based materials via covalent bonding. The structural characterization, as well as, the determination of photophysical proprieties will allow the pre-evaluation of their own characteristics. In the presence of light, the microbiocidal effect of the new materials will be evaluated on distinct pathogenic microorganisms present in wastewater samples. The best materials will be proposed for patents.