Resumen de Fungicides alternatius per a la indústria de la pell: comparació amb productes convencionals
This thesis is focused on the search of alternatives to fungicides conventionally used in the tanning industry. These chemicals must be effective against a large number of fungi less toxic, more environmentally friendly and economically attractive. The main objective is to evaluate the fungicidal capacity of selected alternative compounds (Directive 98/8/CE); diiodometil p-tolylsulfone (DIMPTS), 3-Iodo-2-propynyl butylcarbamate (IPBC), thiabendazole (TBZ) and dodicine clorhydrate (TEGO) versus different types of fungi. The strains used belong to the most common species in tanneries: Aspergillus brasilensis, Trichoderma harzianum, Alternaria alternata i Penicillium funiculosum. In addition, different fungi from real pollution tannery have been isolated from the industry; these are species more resistant to common antifungal chemicals. The antifungal capacity has been compared with selected fungicides normally used in tanneries, such as 2-(thiocianometilthio)-1,3-benzothiazole (TCMTB) and the mixture of phenolic compounds, p-chloro-m-cresol (PCMC) and o-phenylphenol (OPP). First, the Minnimum Inhibition Concentration (MIC) of molecules has been determine against the selected fungi. Subsequently, the effectiveness of different offers of chemicals has been compared using wet blue leather. To complete the tests, selected fungicides have been applied in three different processes: a chrome tanning process, a preservative pickling process and a fatliquoring process of hides tanned with vegetable extracts. Further studies consisted of a microbiological control of samples inoculated with fungi common in tannery, determination of the minimum effective amount of chemical and determination of the fungicide content on the different layers of the hide. The evaluation of the toxicity of process wastewaters associated with their application and the economic viability of the proposed alternatives complemented the studies. The higher antifungal capacity of two of the four fungicides proposed, DIMPTS and IPBC, employed in different processes confirms that are good candidates to be used in the leather sector. Hides obtained using alternative fungicides showed good characteristics, and, from the environmental impact point of view, toxicity from wastewaters was lower for the alternative chemicals against those commonly used.
