Description: Das Projekt "Entwicklung von umweltvertraeglichen photoaktivierbaren Verbindungen fuer die Behandlung von Mikroorganismen in verunreinigtem Wasser" wird vom Umweltbundesamt gefördert und von Max-Planck-Gesellschaft zur Förderung der Wissenschaften, Max-Planck-Institut für Strahlenchemie durchgeführt. This project aims at defining the scope and potential of a novel technique, based on the use of visible light-activated photosensitizing agents for the decontamination of microbially polluted water. The emphasis is placed on the photosterilization of waste waters from aquaculture ponds, namely a well-defined and readily controlled system; however, it can be potentially extended to the treatment of more complex systems, such as water to be used in food industry and land irrigation. While fish-farming is undergoing a rapid expansion worldwide, serious problems are caused by the high concentration of pathogens typical of intensive culture systems, which reduce the productivity and may expand the infections beyond the farm limits in case of poor management of waste waters. Frequently adopted approaches for water treatment are based on the introduction of antibiotics. UV light-sterilization has been also proposed to avoid the use of chemicals, although this type of light requires a fairly complex technology, is intrinsically mutagenic for bacteria and is characterized by a limited degree of penetration into turbid waters, besides requiring cogent protective actions for the operators. Our approach is based on the following elements: (a) Porphyrin-type photosensitizers, which are atoxic being naturally present in animals and plants, and absorb essentially all light wavelengths, thereby allowing their efficient photoactivation even by light regimes of low intensity; (b) An inert support to which porphyrins are covalently bound, so that no chemical is dissolved in the medium: the support (resins/clays) is readily swollen by water, allowing an intimate contact between the microbial cells and the bound photosensitizer; (c) Visible light (tun gsten or halogen lamps) which requires a simple and inexpensive technology, is safe for the operators and is endowed with a deeper penetration power into water; (d) A volatile cytotoxic agent, i.e. an activated oxygen derivative, which can diffuse up to 1.5 mm from its generation site in air-equilibrated water and attacks the cell from outside, hence cell death occurs via membrane damage, thereby minimizing the risk of mutagenic effects. The main goal of the project is the definition of protocols for the photoinactivation of fish pathogens by support-bound porphyrins and to apply such protocols at a pilot plant scale. The latter task will be primarily performed in Israel, Morocco and Tunisia and Argentina, i.e. under different environmental conditions, in order to tailor the irradiation protocol as a function of specific local conditions. The final protocol(s) will be developed through a continuous feedback with the other partner, of the entwork, having a long-standing experience in the synthesis of photosensitizersupport systems, their photophysical characterization, and bacteria photosensitization.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Halogenlampe ? Antibiotikum ? Abwasserverrieselung ? Fisch ? Abwasserverregnung ? Lebensmittelindustrie ? Sauerstoff ? Wasserschaden ? Argentinien ? Israel ? Main ? Marokko ? Tunesien ? Landwirtschaftlicher Betrieb ? Lichttechnik ? Wasserreinigung ? Bakterien ? Chemikalien ? Energie ? Wasseraufbereitung ? Wasserverschmutzung ? Mikroorganismen ? Tier ? Wasser ? Aquakultur ? Abwasserwirtschaft ? Versuchsanlage ? Krankheitserreger ? Standortbedingung ? Gewässer ? Infektion ? Produktivität ? Risiko ? Photosensibilisierung ?
Region: Nordrhein-Westfalen
Bounding box: 6.76339° .. 6.76339° x 51.21895° .. 51.21895°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1996-09-01 - 1999-08-31
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