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Doctoral thesis, 2000

Occurrence and fate of organic contaminants in wastes

Nilsson, Marie-Louise

Abstract

This thesis deals with the determination of organic contaminants in wastes and is part of the multidisciplinary faculty programme 'Biological waste in circulation between urban and rural areas - biology and flow of energy and material' which started at SLU in 1994. To ensure long-term sustainability of food production it is important to recycle resources such as the nutrients and organic material in organic waste. The biodegradable fraction of source separated household waste is attractive as raw material for composting and anaerobic digestion, because the products can be used in agriculture and horticulture. Quality is an important aspect on compost and anaerobically digested organic household waste, and it is important to ensure that the products are not contaminated. As the available information on organic contaminants in the biodegradable fraction of household waste and the products thereof is limited, an important goal with this work was to increase the knowledge of organic contaminants in these material as a foundation for future studies to reduce the environmental risk from these materials. Chlorinated paraffins (CPs) were found in fresh household waste. CPs are a complex mixture of chlorinated alkanes with varying (10-30) carbon chain lengts and varying (30- 70%) unspecific chlorination. The high numbers of isomers and homologues complicates the determination of CPs. We found that multivariate analysis can be used to interpret chromatographic data of CPs and this was used to characterise the CP contamination of houshold waste. It is presently impossible to pin-point the source of CP contamination using the data available, but most probably the contamination occurs during the collection of the waste. To further improve the determination of CPs an extraction method using high diffusion liquids, pressurised liquid extraction (PLE) was developed. PLE was shown to be a suitable technique for extracting CPs from complex matrices such as fresh household waste. A source close to the collection chain is also indicated for polychlorinated biphenyls (PCB). The PCB-profile found in the fresh household waste resembles that of a low chlorinated technical product. The PCB-profile expected in this type of material would originate from waste of animal origin in which the low chlorinated congeners have been degraded and the more highly chlorinated and persistent congeners dominate. Differences in the degradation rate of PCBs between composting and anaerbically degestion of the waste were also observed. A third indication of a contamination source in the collection chain is the presence of the n-alkanes in the fresh and anaerobically digested household waste, which suggest a petrogenic rather than a biogenic origin. Since the major part of the organic fraction of household waste is of plant origin, much of which is treated with pesticides, it was expected to find pesticides in the waste. Many of the pesticides were not degraded during composting or anaerobic digestion, and two that were not found in the waste were found in compost or anaerobically sludge. In these cases the organic bulk material is mineralized more rapidly than the pesticides. The anaerobic biotransformation of nonylphenol mono- and diethoxylates (NPEOI-2) was studied in sludge, landfilled sludge and landfilled municipal solid waste. The NPEO1-2 are degradation products of nonylphenol ethoxylates (heavy duty surfactants) and are further degraded to nonylphenol (NP) which is far more persistent and ecotoxic than its parental compou

Keywords

household wastes

Published in

Acta Universitatis Agriculturae Sueciae. Agraria
2000, number: 249
ISBN: 91-576-5759-9

      SLU Authors

    • Nilsson, Marie-Louise

      • Department of Environmental Assessment, Swedish University of Agricultural Sciences

    UKÄ Subject classification

    Agricultural Science

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/78509