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(T/EH027) New Environmental Technologies in Leather Industry - Wastewater decontamination. Catarino, Justina1, Lança, Ana1, Silva, Luis1, Mendonça, Elsa1, Picado, Ana1, Fernandes, Alexandra1, Peneda, Maria1, Pinho, Norberta2, 1 2 ABSTRACT- A study on leather industry wastewaters minimisation contributed to the application of new technologies associating simultaneously environmental and economical aspects to achieve better industry performances. With these results the best options in terms of eco efficiency aspects were proposed, focusing those which can get more economic benefits in water and raw material consumption and at the same time provide environmental compliance. In a Portuguese Leather industry selected to be a demonstration unit, some treatment options (screening, textile membrane filtration, flocculation, microfiltration, flotation and ultrafiltration) were experimented and the different process units liquid effluents were chemically and ecotoxicology monitored. The operation sequence suggested for the first and the second soaking effluent is a wastewater screening followed by filtration on textile membranes, prior to ultrafiltration. For liming wastewater it is envisaged besides the pre-treatments, to include a flotation operation prior to ultrafiltration, allowing better remotion rates of pollution load and an improvement of the respective fluxes. We should notice that the maximum fluxes are achieved with membranes of 0,20 Key words: Leather, wastewater, ultrafiltration, bioassays |
m pore size for microfiltration and cut-off 15 KD for ultrafiltration. The use of ultrafiltration is more advantageous than microfiltration. In that way it was possible to achieve water savings, a natural resource of the greatest importance, regarding material use and costs. In particular, concerning liming effluents, it is most interesting to reuse wastewater, allowing water and sulphides savings which may be reincorporated in the process. Performed bioassays pointed out that the liming effluent is the most ecotoxic. Along treatment process an increase of the CI 50 values was observed, but a treated effluent without ecotoxicity was not achieved. This kind of approach allows us to associate, in the company, productivity factors to environmental savegard, and that way to contribute to sustainable production for tanneries. The treatment options studied were promising in reducing pollution loads and a recycling strategy could be faced.