Constructed wetland

Turon C, Comas J, Alemany J, Cortes U, Poch M (2007) Environmental decision support systems a new approach to support the operation and maintenance of horizontal subsurface flow constructed wetlands. Ecol Eng 30(4) 362-372... 

Turon C, Comas J, Torrens A, Molle P, Poch M (2008) Improvement of sand filter and constructed wetland design using an environmental decision suport system. J Environ Qual 37 (4) 1644-1647... 

Turon C, Alemany J, Bou J, Comas J, Poch M (2005) Optimal maintenance of constructed wetlands using an environmental decision support system. Water Sci Technol 51(10) 109-117... 

In this study, a constructed wetland was designed to remove BOD5 together with total nitrogen (T-N) from municipal wastewater. The designed wetland was composed of the aerobic tank and anaerobic/anoxic one which was connected in series immediately after the aerobic one, and could treat 100 m raw municipal wastewater every day. Influent... 

The constructed wetland was composed of the two tanks connected in series the one is the aerobic tank and the other is the anaerobic/anoxic one (Figure 1). The former tank could remain aerobic owing to the continuous supply of air through the natural draft system (Figure 2) whose driving force for airflow was the temperature difference between the... 

Figure 2. The natural air draft system installed inside the aerobic tank of the constructed wetland.

Figure 3. The detailed photograph of the wastewater distribution lines onto the surface of the aerated constructed wetland.

Figure 4. The influent and effluent concentrations of BOD5 (left) and T-N (right) in the constructed wetland.

Additional removal of BOD5 and T-N could be obtained at the anaerobic/anoxic tank of the constructed wetland. About 57 % of the ranaining BOD5 was removed at the anaerobic/anoxic tank. More than 74 % of the remaining T-N was denitrified, and the average concentration of T-N at the final effluent was 6.9 mg/L. The maximum available capacity for nutrient uptake in plants was far less (of the order of 5 %) than the loading rate of nutrients to the constructed wetland. 

Biofihn concentrations attached onto the surface of the sands and gravels in the aerobic tank were measured at 120 different location of the constructed wetland at different times (6 months, 12 months, 18 months and 24 months). The concentrations of the biofilm increased continuously upto 6 month operation, but thereafter remained almost imchanged upto 24 months. Figure 7 and 8 show the concentrations and distributions of biofilms attached onto the the surface of the sands and gravels of the aerobic tank, respectively. The attached biofilm was well distributed over the aerobic tank, and the total volume of the attached biofilm occupied just about 0.5% of the initial void volume of the aerobic tank. 

The constructed wetland with the aerobic tank and anaerobic/anoxic tank connected in series was employed for the treatment of raw municipal wastewater. More than 94% of the initial BOD and 80% of the initial T-N could be removed. Successful biological nitrification was... 

Department of Land and Water Conservation (DLWC). The Constructed Wetlands Manual, New South Wales, Australia, 1998. 

U.S. Environmoital Protection Agency, Subsurface Flow Constructed Wetlands for Wastewater Treatment A Technology Assessment, Report EPA/ 832-R/93/001. Washington, D.C, 1994. 

Matamoros V, J Gardla, JM Bayona (2005) Behavior of selected pharmaceuticals in subsurface flow constructed wetlands a pilot-scale study. Environ Sci Technol 39 5449-5454. 

A Holistic Approach to Phytofiltration of Heavy Metals Recent Advances in Rhizofiltration, Constructed Wetlands, Lagoons, and Bioadsorbent-Based Systems... 

Phytofiltration, a specific strategy of phytoremediation, is the use of plants to remove contaminants from water and aqueous waste streams. Three different systems (Figure 10.1) can be considered within this strategy (a) rhizofiltration (the use of hydroponically cultivated plant roots),31112 (b) constructed wetlands (CWs) and lagoons, and (c) bioadsorbents-based systems.1... 

A discussion of the use of floating aquatic plants for metal removal at large scale in surface flow constructed wetlands (SFCWs) is provided below. 

Environmental Protection Agency (EPA), Manual, Constructed Wetlands Treatment of Municipal Wastewaters, EPA/625/R-99/010. Available at http //www.epa.gov/ORD/NRMRL, 2000a. 

Kadlec, R., Knight, R., Vymazal, J., Brix, H., Cooper, R, and Haberl, R., Constructed Wetlands for Pollution Control. Processes, Performance, Design and Operation, IWA Publishing, London, 2000. 

United States Department of Agriculture (USDA), Constructed Wetlands. Available at http //www.wsi. nrcs. usa.gov/ products/W2Q/AWM/docs /NEH637Ch3Constructed, 2002. 

Wallace, S., Feasibility, Design Criteria, and O M Requirements for Small Scale Constructed Wetland Wastewater Treatment Systems, IWA Publishing, London, 2006. 

Kandasamy, J. and Vigneswaran, S., Constructed Wetlands, Nova Science Publishers, New York, 2008. 

Vymazal, J., Removal of nutrients in various types of constructed wetlands, Science of the Total Environment, 380,48-65, 2007. 

Greenway, M., The role of macrophytes in nutrient removal using constructed wetlands, in Environmental Bioremediation Technologies, Singh, S.N. and Tripathi, R.D., Eds, Springer, Berlin, Heidelberg,... 

Olgutn, E.J., Vidal, M., Sanchez-Galvan, G., and Houbron, E., Bioadsorption and intracellular accumulation factors of lead in constructed wetlands microcosms with Salvinia minima operating continuously The effect of light intensity, International Symposium on Biotechnology, Dalian, China, October 12-17,... 

Bragato, C., Brix, H., and Malagoli, M., Accumulation of nutrients and heavy metals in Phragmites australis (Cav.) Trim ex Steudel and Bolboschoenus maritimus (L.) Palla in a constructed wetland of the Venice lagoon watershed, Environmental Pollution, 144, 967-975, 2006. 

Gruber, H., Wiessner, A., Kuschk, P., Kaestner, M., and Appenroth, K.J., Physiological responses of Juncus effusus (rush) to chromium and relevance for wastewater treatment in constructed wetlands, International Journal of Phytoremediation, 10 (2), 79-90, 2008. 

Maine, M.A., Sufie, N., Hadad, H., Sanchez, G., and Bonetto, C., Influence of vegetation on the removal of heavy metals and nutrients in a constructed wetland, Journal of Environmental Management, 90 (1), 355-363, 2009. 

Nyquist, J. and Greger, M., A field study of constructed wetlands for preventing and treating acid mine drainage, Ecological Engineering, 35 (5), 630-642, 2009. 

Liao, S.W. and Chang, N.L., Heavy metal phytoremediation by water hyacinth at constructed wetlands in Taiwan, Journal of Aquatic Plant Management, 42, 60-68, 2004. 

Jayaweera, M.W., Kasturiarachchia, J.C., Kularatnea, R.K.A., and Wijeyekoon, S.L.J., Contribution of water hyacinth (Eichhomia crassipes (Mart.) Solms) grown under different nutrient conditions to Fe-removal mechanisms in constructed wetlands, Journal of Environmental Management, 87 (3), 450-460, 2008. 

Azaizeh, H., Salhani, N., Sebesvari, Z., Shardendu, S., and Emons, H., Phytoremediation of selenium using subsurface-flow constructed wetland, International Journal of Phytoremediation, 8 (3), 187-198, 2006. 

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