| Pilot Demonstration Project: Aquafix Water Treatment |
April 2003 |
| Author(s): Karl Ford, Bureau of Land Management (BLM) |
2003 Department of the Interior Conference on the Environment, 13-15 May 2003, Phoenix, Arizona
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| Mine: Dinero Tunnel, Colorado; Alameda Mine, Oregon |
Waste Type: AMD |
Contaminant(s): aluminum, cadmium, copper, iron, lead, manganese, zinc |
Technology Type: Aquafix |
| Keywords: acid mine drainage, AMD, calcium oxide lime |
| Abstract: A demonstration project was undertaken at two BLM sites by the National Science and Technology Center to evaluate the performance of the Aquafix water treatment system, which does not require power or daily monitoring. The Dinero Tunnel is a source of acid mine drainage that flows into the Upper Arkansas River watershed near Leadville, CO. With the support of the U.S. EPA, BLM funded and directed the installation of a lime dosing machine rented from Aquafix Water Treatment Systems of Kingwood, WV. A similar project was conducted at the Almeda Mine near Grants Pass, OR. The units were installed during the summer of 2002 and operated for three months. Each unit dispenses calcium oxide lime from a bin via a water wheel. At the Colorado site, the inlet hose became clogged with iron hydroxides (yellow boy), which reduced the flow and the lime dispensing rate. Rpms and pH values were consistently lower than expected. It became necessary to disconnect the hose each week and flush out the sludge. In retrospect, this should have been done even more frequently. Operational problems also were encountered in Oregon with accumulation of the granular lime below the dispenser. Bridging of the lime into the dispenser occurred, thus halting dispensing of the lime. The problem resulted from the low flow of the adit water and the granular form of the lime. Various cones, wind screens, and flumes were tried, and eventually an eddy flow was created that corrected the bridging problem. At the Oregon site, metal concentration reductions ranged from 94 to 99% for the principal acid mine drainage metals of aluminum, cadmium, copper, iron, lead, manganese, and zinc. Water quality standards can be achieved even for trace metals if the target pH of 9.0 is maintained. Performance at the Colorado site was less successful due to operational problems. Several important lessons were learned on the use of this promising technology and recommendations are provided. The Aquafix unit cost approximately $17,000 and is portable, sturdy and a promising inexpensive technology. A long-term commitment to maintaining the unit is necessary. |
For more information online:
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Contact: Mike Jenkins, Aquafix,304-329-1056, mjj@aquafix.com |
