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Laspidou, C. S. (2005). Constructed wetlands technology and water quality improvement: Recent advances. Proceeding of the 9th International Conference on Environmental Science and Technology Vol B – Poster Presentations, , B503–B508.
Abstract: Today's demands for improved water quality in receiving waters are widespread and require the implementation of systems that are natural, low-cost and minimal-maintenance that could effectively treat polluted discharges. Wetlands are such systems and are recently receiving a lot of attention from scientists, ecologists and engineers, as they are deemed appropriate for reducing the impact of effluent and run-off on receiving waters. Since a large part of natural wetlands have been lost-about 53% of them in the United States from the 1780s to the 1980s-management options for improving receiving water quality, water reclamation and reuse involve the application of constructed wetlands technology.
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Maniatis, T. (2005). Biological removal of arsenic from tailings pond water at Canadian mine. Arsenic Metallurgy, , 209–214.
Abstract: Applied Biosciences has developed a biological technology for removal of arsenic, nitrate, selenium, and other metals from mining and industrial waste waters. The ABMet((R)) technology was implemented at a closed gold mine site in Canada for removing arsenic from tailings pond water. The system included six bioreactors that began treating water in the spring of 2004. Design criteria incorporated a maximum flow of 567 L/min (150 gallons per minute) and water temperatures ranging from 10 degrees C to 15 degrees C. Influent arsenic concentrations range from 0.5 mg/L to 1.5 mg/L. The ABMet((R)) technology consistently removes arsenic to below detection limits (0.02 mg/L). Data from the full scale system will be presented, as well as regulatory requirements and site specific challenges.
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Gusek, J. J. (2005). Design challenges for large scale sulfate reducing bioreactors. Contaminated Soils, Sediments and Water: Science in the Real World, Vol 9, 9, 33–44.
Abstract: The first large-scale (1,200 gpm capacity), sulfate-reducing; bioreactor (SRBR) was constructed in 1996 to treat water from an underground lead mine in Missouri. Other large-scale SRBR systems have been built elsewhere since then. This technology holds much promise for economically treating heavy metals and has progressed steadily from the laboratory to industrial applications. Scale-up challenges include: designing for seasonal temperature variations, minimizing short circuits, changes in metal loading rate s, storm water impacts, and resistance to vandalism. However, the biggest challenge may be designing for the progressive biological degradation of the organic substrate and its effects on the hydraulics of the SRBR cells.
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Wiseman, I. M., Rutt, G. P., & Edwards, P. J. (2004). Constructed wetlands for minewater treatment: Environmental benefits and ecological recovery. Water and Environment Journal, 18(3), 133–138.
Abstract: The ecology of the River Pelenna (in South Wales) was impoverished by polluted discharges from abandoned coal mines. A series of passive constructed wetlands was created in order to treat these discharges and to improve the ecology of the river. A three-year Environment Agency R&D project investigated the performance, environmental benefits and sustainability of the constructed wetlands. It showed that the treatment systems were removing most of the iron contamination. In the reaches downstream from the minewaters, the dissolved-iron concentration quickly dropped below the target level. Invertebrate abundance, trout and riverine bird populations increased in following years. However, occasional overflows from the systems have significantly affected the ecology of one stretch of river The research work has provided an insight into the potential for ecological recovery associated with future minewater treatment.
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Zhuang, J. M. (2004). Lignor(TM) process for acidic rock drainage treatment. Environ. Technol., 25(9), 1031–1040.
Abstract: The process using lignosulfonates for acidic rock drainage (ARD) treatment is referred to as the Lignor(TM) process. Lignosulfonates are waste by-products produced in the sulfite pulping process. The present study has shown lignosulfonates are able to protect lime from developing an external surface coating, and hence to favor its dissociation. Further, the addition of lignosulfonates to ARD solutions increased the clotting and settling rate of the formed sludge. The capability of lignosulfonates to form stable metal-lignin complexes makes them very useful in retaining metal ions and thus improving the long-term stability of the sludge against leaching. The Lignor(TM) process involves metal sorption with lignosulfonates, ARD neutralization by lime to about pH 7, pH adjustment with caustic soda to 9.4 – 9.6, air oxidation to lower the pH to a desired level, and addition of a minimum amount of FeCl3 for further removal of dissolved metals. The Lignor(TM) process removes all concerned metals (especially Al and Mn) from the ARD of the Britannia Mine (located at Britannia Beach, British Columbia, Canada) to a level lower than the limits of the B.C. Regulations. Compared with the high-density sludge (HDS) process, the Lignor(TM) process has many advantages, such as considerable savings in lime consumption, greatly reduced sludge volume, and improved sludge stability.
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