PARENT SESSION

1B+C Abiotic Transformations + Biodegradation
Poster Hall
8:30 AM - Monday, 28 April 2003
Chair: Peijnenburg, W.¹, ¹
Co-chair: Jafvert, C.T.², Gombar, V.K.³, ^{2 3}

(MOP/35) In-vessel composting as a bioremediation technology of PAH-contaminated solid wastes.

Antizar-Ladislao, Blanca¹, Lopez-Real, Jose Maria¹, Beck, Angus¹, ¹ Imperial College of Science, Technology and Medicine, Wye, Ashford - Kent, UK

ABSTRACT- Appropriate disposal and/or clean-up of contaminated wastes is a legal requirement in most countries. However, the costs involved are often high. Land-filling remains the most common means of disposal in most countries but it is becoming increasingly expensive and therefore volumes must be reduced by finding alternative uses for wastes traditionally landfilled. Furthermore, in Europe future regulatory changes, to come into force by 1st January 2003, will require landfill operators to pre-treat wastes to reduce their contamination prior to landfilling. A novel, simple cost effective way to achieve this using machinery usually available on most United Kingdom landfill sites is to use composting as a biotreatment technology. During composting, reductions in waste volume of up to 50% might be typically be expected Additionally during the composting process bacterially catalysed aerobic degradation has been reported to result in substantial declines in contaminant loadings. The present study is being conducted to investigate the biodegradation of 16 polycyclic aromatic hydrocarbons (PAHs) listed as United States Environmental Protection Agency (USEPA) Priority Pollutants, present in contaminated soil using composting technology. Preliminary investigations were carried out to optimise the soil composting temperature, and soil to green waste ratio. Different lab-scale batch composters were aerated and placed in several constant temperature incubators at three different temperatures 40⁰C, 55⁰C and 70⁰C for a period of 30 to 90 days. The soil was augmented with green waste, which was used as a bulking agent and nutrient supplement, in quantities ranging from 0-70% dry weight basis. Samples were extracted using accelerated solvent extraction (ASE) and analysed on the Gas Chromatograph – Mass Spectra or Spectrofluorometer to determine the reduction in the 16-PAHs concentration. Analysis of these samples is in progress. In future experiments using the Sirocco full-scale-in-vessel composter, the soil/green waste mixtures will be monitored in the same way as the batch composters to evaluate the possibilities for scale-up and to determine the optimum operating conditions for PAH biodegradation during composting.

Key words: Composting, Bioremediation, PAH, Solid wastes