Pooran Appadu1, Vadim Kislitsin2, Birendra Adhikari1, Lauren Mercier1, Mike Chae1, Phillip Y. K. Choi2 and David Bressler1.
1Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
2Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada.
Canada has the largest and most developed oil sand reservoirs in the world. However, the industry negatively impacts the environment. Water reservoirs (or tailings ponds) are affected by the deposition of solid particles such as clay, sand, and residual bitumen. These particles remain unsettled for decades if left untreated. The discharge is toxic to local flora and fauna. In addition, only the top 3 metres of water can be recycled. As tailings are continuously added, the total area of tailing ponds in Alberta is expected to increase in size from 176 km2 to 250 km2 by 2020.
Canada is making great strides towards curtailing the effects of the oil sands industry. For example, in July, 2012, the Energy Resource Conservation Board instituted Directive 074. This directive requires that 50% of the solids in the oil sands tailings be removed from the waste stream. One way to comply with Directive 074 is to use a flocculant – a chemical that promotes the aggregation of suspended particles to form a floc. Several current industrial practices are capable of meeting the requirements of Directive 074, but there are several economic and environmental problems associated with each. For example, inorganic flocculants such as aluminium sulphate produces a large amount of secondary sludge that results in toxicity and disposal concerns.
This project aims to convert Specified Risk Materials (SRMs) - the parts of cattle where the prion protein that causes mad cow disease concentrate – into an industrial flocculating agent for the settling of oil sands tailings. This contribution will present the flocculating performance of peptides recovered from the thermal hydrolysis of SRMs, chemically modified peptides, and proposals for future work.