Polybrominated diphenyl ethers (PBDEs) have been used for decades as flame retardants in polymeric materials. Products containing lower brominated congeners have been banned because of concerns about their toxicity to neurological, reproductive and endocrinal systems. Restrictions on the use of the deca-BDE mixture, which contains 97% of the fully brominated congener BDE-209, have been initially delayed. Nowadays the addition of BDE-209 to the Stockholm Convention on Persistent Organic Pollutants is under evaluation. BDE-209 fate in soil, as for other hydrophobic organic compounds, is strongly related to soil organic fraction. This thesis investigates BDE-209 sorption kinetics and identifies other factors important for evaluating BDE-209 mobility, degradation and bioavailability in soil. Additionally it moves the first steps in the development of a novel bioaugmentation technique through fungi. For this purpose, HPLC analytical methods and extraction techniques commonly used for hydrophobic organic compounds (HOC) have been tested for analysis of BDE-209 in water and soil samples. The best recoveries values were obtained by evaporation and substitution of water (WES) and by pressurised liquid extraction (PLE) of soil. Regarding BDE-209 sorption in soil, the sorption kinetic profiles for two soil matrixes belonging to the mineral domain (kaolin) and organic matter domain (peat) were studied separately. Sorption on kaolin was much faster than in peat (4 hours compared to more than 10 days). This approach made it possible to identify other important factors influencing BDE-209 sorption and partitioning processes: clay minerals and dissolvable organic matter. In relation to the biodegradation aspect, this thesis investigated the tolerance of P.ostreatus (a specie of white rot fungus with documented mycoremediation ability) to BDE-209. The fungus mycelium in co-existence with a soil bacterium demonstrated the ability to colonised straw contaminated with BDE-209 up to 1 mg/kg. The results encourage further investigation on P. ostreatus ability to degrade BDE-209.
|Date of Award||25 Nov 2016|
- University Of Strathclyde
|Sponsors||University of Strathclyde|
|Supervisor||Christine Switzer (Supervisor) & Lorraine Gibson (Supervisor)|