Contribution of southern fruit peels to the contamination of biological waste

Abstract

The aim of this study was to estimate the pesticide contamination of biological waste caused by the peels of southern fruits. For this reason 105 samples of southern fruit peels were analysed for 18 different pesticides. Pesticide residues were found in all peels. The pesticides found most frequently and in the highest concentrations were the fungicides thiabendazole and ortho-phenyl-phenol. The peels of citrus fruits generally contained higher pesticide concentrations than those of bananas and kiwis. Based on these findings the pesticide contamination of German biological waste caused by southern fruit peels was estimated. Also, the influence of the four main pesticides on the microbial gas production in the acidogenic phase of biological waste fermentation was investigated by means of simple batch-assays. Ortho-phenyl-phenol was the only pesticide that irreversibly inhibited the gas production, but only in concentrations which exceeded those expected in biological waste by several orders of magnitude.