2014-Sustainable Industrial Processing Summit
SIPS 2014 Volume 1: Mining
| Editors: | Kongoli F |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2014 |
| Pages: | 424 pages |
| ISBN: | 978-1-987820-03-4 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
CD shopping page
The use of engineered bioreactor systems for treating runoffs and leachates from artisanal gold mining operations
James Higgins1; Christopher Anderson2;1ENVIRONMENTAL DEVELOPMENT CORPORATION, Mississauga, Canada; 2MASSEY UNIVERSITY, Palmerston North, New Zealand;
Type of Paper: Regular
Id Paper: 394
Topic: 1
Abstract:
There is increased interest in developing advanced wastewater treatment technologies for the management of otherwise difficult-to-treat (recalcitrant) wastewaters such as Mining Influenced Waters (MIWs, e.g., acid rock drainage) from metal mine sites, industrial process waters from industrial facilities such as those associated with artisanal mining operations, landfill leachates, and contaminated runoff and percolates from phytoremediation sites. While the management of such waters can be achieved using conventional wastewater treatment methods, such methods are costly, labour-intensive, often generate byproducts which in turn must be managed, and their practicality for very long term treatment is questionable. The Mining Industry has been active in defining much more passive bioreactor-based methods to treat MIWs using aerobic and anaerobic bioreactors such as aerated sub-surface flow engineered wetlands (EWs) for removing contaminants amenable to aerobic degradation or conversion (Higgins et al., 2010), and anaerobic sulphate-reducing biochemical reactors (BCRs) for removing dissolved metals and metalloids (Mattes et al., 2010).
Engineered Bioreactor Systems (EB Systems) have now been developed which allow the very effective treatment of many sorts of otherwise recalcitrant wastewaters in more economic treatment systems; ones which require little operator attention or maintenance; and which can easily and consistently meet stringent discharge criteria over extended periods. Semi-passive EB Systems can involve in-ground aerobic and anaerobic bioreactors which may be insulated, buried or located under deep water to allow them to operate efficiently even under the severest environmental conditions.
This paper will review the classification of passive and semi-passive in-ground wetlands and bioreactors and the conditions needed for their long-term successful operations. In particular, the applicability of integrating water treatment with phytomining to sustainably manage mine waste at artisanal and small-scale gold mines will be explored. The potential of phytomining residual gold from ASGM tailings was proposed by Krisnayanti et al. (2012). However, the potential discharge of leachate from phytomines is problematic. EB Systems to treat recalcitrant wastewaters at ASGM could address this problem. The paper will summarize the results of bench, pilot- and field-scale projects using them. The paper also will present the results of test programs which have allowed the updating of the designs of engineered bioreactors from their earlier empirical bases to those based on advanced reaction kinetics.