Abstract
The aim of this study is to investigate the extraction of oil from scum obtained from a municipal wastewater treatment plant. Various parameters such as solvent volume, temperature, agitation and moisture content were optimized to maximize the oil extraction efficiency using freeze-dried scum. The oil extraction efficiency was compared for each parameter using hexane and petroleum diesel as a solvent. The optimum physical parameters for oil extraction using freeze-dried scum were 75 g solids/L solvent, temperature 60 °C, agitation 300 rpm for 60 min, and maximum oil extraction efficiency of 100 and 94.3% w/w was obtained using hexane and petroleum diesel, respectively. The obtained results using 1 g of scum were further validated using 1 kg of wet scum under optimized conditions, and oil extraction efficiency of 94.1 ± 1.3 and 91.3 ± 4.2% w/w was obtained using hexane and petroleum diesel, respectively. Furthermore, ex situ transesterification was performed, and results showed that scum had a higher neutral lipid. In brief, scum is a potential feedstock for the production of biodiesel, and more work on this must be done in future.
Acknowledgements
Sincere thanks are given to the Natural Sciences and Engineering Research Council of Canada (Grant A 4984 and Canada Research Chair) for their financial support. The views and opinions expressed in this paper are those of the authors. We are grateful to technical staffs of INRS-ETE, for their timely help to analyze the sample on FT-IR and GC-FID.