Effetti del percolato di discarica RSU sullo sviluppo embrional di Danio rerio

Effects of landfill leachate(Percolato) on the embryonic development of zebrafish (Danio rerio) Abstract Leachate is a liquid derived from the infiltration of rainwater into the landfill which, going through the waste, is enhanced by substances resulting either from the decomposition of the waste and liquids derived from the metabolism of the present organic colliquativa. The result is a complex mixture of organic and inorganic substances, and in particular, in the leachate samples analyzed from different systems of landfills, it appears in the inorganic component a high concentration of ammonia, nitrates, sulfates, iron and zinc. In the present work we attempted to assess the acute toxicity of leachate using specific ecotoxicological models and, in a more detailed study, to test this pollutant on Danio rerio embryos to check for any morphologiccal changes and teratogenic aspects. In particular, the exposure to the leachate showed a high mortality, a declining trend in the development of zebrafish embryo from the earliest stages of gastrulation, however these effects were closely related to the dose of leachate used. The object of this study was also to evaluate new scientific approaches for the detoxification of leachate based on the capacity of self-detoxification, using active biomass from urban wastewater treatment plant and bacterial strains, specially selected from the same leachate. The data obtained from toxicological tests show a high toxicity of landfill leachate with obvious alterations in embryonic development of zebrafish and alterations of phenotypic effects derived with dilutions of leachate pressures. The detoxification of the leachate by biological approach has not produced encouraging results, however alsoo indicating that the use of more massive bacterial inoculation with selected strains of flocculants or trials in anaerobic environment can provide additional tools for those purposes. Finally, in a preliminary study we tried to use the leachate, diluted appropriately, such as cells culture of microalgae, especially the strain Tetraselmis suecica, where we obsereved a good performance of algal growth, letting us introducing new scientific approaches for the treatment of detoxification landfill leachate.