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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Kothe, E. (2005). Molecular mechanisms in bio-geo-interaactions: From a case study to general mechanisms. Chemie Der Erde-Geochemistry, 65, 7–27.
Abstract: The understanding of molecular mechanisms in the cycling of elements in general is essential to our alteration of current processes. One field where such geochemical element cycles are of major importance is the prevention and treatment of acid mine drainage waters (AMD) which are prone to occur in every anthropogenic, modified landscape where sulfidic rock material has been brought to the surface during mine operations. Microbiologically controlled production of AMD leads not only to acidification, but at the same time the dissolution of heavy metals makes them bioavailable posing a potential ecotoxicological risk. The water path then can contaminate surface and ground water resources which leads to even bigger problems in large catchment areas. The investigation of mechanisms in natural attenuation has already provided first ideas for applications of naturally occurring bioremediation schemes. Especially an improved soil microflora can enhance the natural attenuation when adapted microbes are applied to contaminated areas. Future schemes for plant extraction, control of water efflux by increasing evapotranspiration, and by subsequent land use with agricultural plants with biostabilization and phytosequestration potential will provide putative control measures. The mechanisms in parts of these processes have been evaluated and the resulting synthesis applied to derive a bioremediation plan using the former uranium mine in Eastern Thuringia as a case study. (c) 2005 Elsevier GrnbH. All rights reserved.
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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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Murray-Gulde, C. L. (). Contributions of Schoenoplectus californicus in a constructed wetland system receiving copper contaminated wastewater. Water, Air, Soil Pollut., 163(1-4), 355–378.
Abstract: Functional roles of Schoenoplectus californicus, giant bulrush, were evaluated in an 3.2 ha (8-acre) constructed wetland treatment system receiving copper-contaminated water. The constructed wetland used in this research was designed to decrease bioavailable copper concentrations in a wastestream and eliminate associated toxicity to downstream biota by exploiting the thermodynamic processes responsible for copper speciation. This was achieved by integrating carbon, sulfur and copper biogeochemical cycles. In this system, S. californicus, which represents an integral part of the carbon cycle, provides a physical, chemical and biological role in removing metals from the aqueous phase. The specific contributions of S. californicus in this system are to provide a sustainable carbon source for removal of copper by (1) provision of an organic ligand for sorption of copper entering the system, (2) production of organic ligands through growth of S. californicus, (3) accretion of organic ligands over time due to decomposition of S. californicus detritus, and (4) use of organic carbon as an energy source for dissimilatory sulfate production. Shoots and roots of viable S. californicus sorbed 0.88% and 5.88%, respectively, of copper entering the system. The half-life of S. californicus detritus in the constructed wetland system was approximately 184 d, indicating that sufficient detritus will accrete over time, providing binding sites for copper and an energy source for bacterial metabolic processes that contribute to copper immobilization in wetland systems.
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Whitehead, P. G. (2005). Bioremediation of acid mine drainage: an introduction to the Wheal Jane wetlands project. Science of the Total Environment, 338(1-2), 15–21.
Abstract: Acid mine drainage (AMD) is a widespread environmental problem associated with both working and abandoned mining operations. As part of an overall strategy to determine a long-term treatment option for AMD, a pilot passive treatment plant was constructed in 1994 at Wheat Jane Mine in Cornwall, UK. The plant consists of three separate systems; each containing aerobic reed beds, anaerobic cell and rock filters, and represents the largest European experimental facility of its kind. The systems only differ by the type of pre-treatment utilised to increase the pH of the influent minewater (pH<4): lime-dosed (LD), anoxic limestone drain (ALD) and lime free (LF), which receives no form of pre-treatment. The Wheal Jane pilot plant offered a unique facility and a major research project was established to evaluate the pilot plant and study in detail the biological mechanisms and the geochemical and physical processes that control passive treatment systems. The project has led to data, knowledge, models and design criteria for the future design, planning and sustainable management of passive treatment systems. A multidisciplinary team of scientists and managers from the U.K. universities, the Environment Agency and the Mining Industry has been put together to obtain the maximum advantage from the excellent facilities facility at Wheal Jane. (C) 2004 Elseaier B.V All rights reserved.
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