The purpose been made to the synthesis of a collection of efforts to control environmental pollution through the use of wetlands are constructed systems (CWS) in Canada, a detailed review of the CWS. Emphasis was placed on a variety of development, practice and research on the technology of the WCC, placing them in the general context of the need for inexpensive and reliable wastewater treatment systems. We consider the possibility of using the WCC in defense of estuarine quality within the existing legislative framework, as well as a new concept of integrated constructed wetlands (ICWs). In addition, was completed assessment of the effectiveness of the WCC in operation in Canada in the direction of reducing pollution, and in comparison with the WCC operating in other European countries. The need to ensure adequate and relevant data to assist in the further development of the CWS studies and modeling, as well as enhance public confidence is also emphasized.
Table of contents
4.0 Novel developments12
4.1 Tidal flow constructed wetland systems12
4.2 'Anti-sized' constructed wetland systems13
4.3 Dewatered alum sludge based constructed wetland13
Constructed wetlands for wastewater treatment have become increasingly viewed as an option for waste treatment in the past 30 years based on performance, reduce maintenance, calling the alleged nature of technology and installation costs and operating expenses (Brix, 1994; Kadlec and Knight , 1996; USEPA, 1999 and Mitsch and Gosselink, 2000). Statements of wetlands for single-family household sewage, as a rule, groundwater flow systems. These structures consist of septic tanks with two or more wetland cells are composed of gravel substrate on the anchor, with vegetation (USEPA, 1999). These natural systems are known to effectively mitigate a variety of pollutants, including fecal enteric, total suspended solids and biochemical oxygen demand (BOD) (Wood, 1995; Nokes et al., 1999 and Mitsch and Gosselink, 2000). Treatment benefited wetlands for use in areas with humid or impermeable soils that do not support the more traditional natural soil-filtration column. Several studies provide Lower installation costs of treatment wetlands as the benefits of using these systems in rural environments where traditional centralized wastewater treatment is not cost-effective option (Reed, 1993, Cooper et al., 1996; Neralla et al. , 2000 and Ogden, 2001).
The complete system costs over the projected life of the wetland treatment systems are not adequately explored. In most cases the cost of the system based only on capital expenditures incurred during the construction and operating costs expended in the operation. The effective lifespan of these systems are usually not considered because of the uncertainty associated with natural variables that exist in wetlands, such as loading rate, size and maintenance (Kadlec and Knight, 1996 and Mitsch, WJ and Gosselink JG, 2000. Wetlands (third ed.), Moscow: Mir, York.Mitsch and Gosselink, 2000). Any potential aesthetic, cultural and ecological benefits of wetlands are recognized (Mitsch and Gosselink, 2000), but not in a quantitative sense, the costs for treatment wetlands. Also, do not take into account the evaluation of internal wetland overall treatment benefit or cost ...