Item Restricted to University of Alberta Users
Log In with CCID to View Item- 135 views
- 1 download
Field-Scale Assessment of Bioremediation Strategies for Two Pit Lakes Using Limnocorrals
-
- Author(s) / Creator(s)
-
The Main Zone and Waterline pit lakes at the Equity Silver Mine near Houston, BC (Canada) are the sites of an ongoing three-year government- and industry-funded research program. In order to assess the feasibility of various bio-remediation strategies, field-scale manipulations were conducted using enclosed mesocosms (limnocorrals). Two manipulation strategies were tested: 1. addition of algal nutrients (phosphate and nitrate) to Main Zone Pit surface waters; and 2. addition of algal nutrients (surface waters) and dissolved organic carbon (deep waters) to the Waterline Pit. Nutrient addition was conducted in order to stimulate algal production and enhance metal scavenging by biogenic particles, while dissolved organic carbon (ethanol) was added to increase oxygen demand and foster the development of sulfate reduction in pit bottom waters. Fertilisation resulted in rapid growth of natural phytoplankton populations in the surface waters of both pits. In the Main Zone Pit, the stimulation of algal growth resulted in the pronounced removal of both dissolved and total metals (Zn and Cu) from surface waters, with higher rates of metal removal being observed at higher nutrient additions. Metal removal could be attributed to the scavenging of dissolved metals by biogenic particles and subsequent particle settling. A similar pattern of removal from surface waters was observed in Waterline Pit (Zn and Cd). The addition of ethanol to deep waters in Waterline Pit was effective in promoting sulfate reduction in the lower layer. The development of reducing conditions resulted in near-quantitative removal of dissolved Zn and Cd, presumably as secondary metal sulfides. Iron, As and Ni profiles in Waterline Pit exhibited no evidence of removal from either surface waters or bottom waters. Collectively, the results demonstrate that the passive forms of bioremediation tested in these pit lakes may be effective for whole pit-lake remediation.
-
- Date created
- 2003
-
- Type of Item
- Article (Published)
-
- License
- Use of this product is restricted to current faculty, staff, and students of the University. It is the responsibility of each user to ensure that he or she uses this product for individual, non-commercial educational or research purposes only, and does not systematically download or retain substantial portions of information. Users may not reproduce or redistribute unprocessed/raw data portions of the data to any third party, or otherwise engage in the systematic retransmission or commercialization of the data.