Usage of laboratory bench scale testing in environmental remediation strategies

Authors: Marques, LLR; Golby, S; Stenroos, P; McClure, T; Turner, RJ; Ceri, H Download Paper

DOI https://doi.org/10.36487/ACG_rep/1152_46_Marques

Cite As:
Marques, LLR, Golby, S, Stenroos, P, McClure, T, Turner, RJ & Ceri, H 2011, 'Usage of laboratory bench scale testing in environmental remediation strategies', in AB Fourie, M Tibbett & A Beersing (eds), Mine Closure 2011: Proceedings of the Sixth International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 433-442, https://doi.org/10.36487/ACG_rep/1152_46_Marques



Abstract:
The oil sands tailings ponds of the Athabasca region, in Northern Alberta, are complex slurries of residual bitumen, oil organics, naphtha diluent, water, sand, clay and heavy metals. These ponds present a unique, yet challenging environment to work with. Remediation of organic contaminant can occur via abiotic and biotic mechanisms. Acceleration of these processes can be achieved through amendments, such as addition of nutrients, surfactants and oxygen, to the contaminated environment which can stimulate microbial growth and metabolism as well as favourable abiotic reactions. Bioremediation efficacy varies greatly from site to site due to changing environmental conditions, soil characteristics, contaminant composition and complexity and indigenous microbial communities. Due to this complexity, assessment of the feasibility of implementing a biologically-based remediation solution and the establishment of optimal treatment conditions for specific sites is critical to ensure efficacy of the bioremediation process, especially in areas exposed to challenging conditions such as mine and oil sands tailings. The bioremediation potential of a site can be evaluated using laboratory or bench scale biotreatability testing, where field conditions are mimicked and the optimal conditions for contaminant degradation are identified. Advanced approaches to bioremediation may also involve the use of mixed species biofilms (microbial consortia). Biodegradation of a compound is often dependent on a microbial consortium, a mixture of species often including bacteria, fungi and archaea (extremophiles), as individual organisms can metabolise only a limited range of substrates. Bioremediation of tailings could be optimised through better understanding and utilisation of diverse microbial groups that are indigenous to mining environments, and through the use of biofilms. A few studies are presented to illustrate: i) the value of bench scale biotreatability testing; ii) the application of non-conventional microbial and molecular techniques; and iii) biofilm methodology; to gather a better understanding and to test the efficacy of bioremediation programmes prior to implementation in the field.

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