Other Countries

Unfortunately, since the Industrial Revolution, most of Europe's rivers (not unlike in the United States) were utilized for transporting wastes to the sea, resulting in harm to human and aquatic health and causing coastal pollution. In earlier times, the rivers could handle the limited wastes discharged, through dilution and natural purification.

Significant progress has been made in treating the wastewater entering Europe's rivers, with measurable improvements in water quality. The agricultural sector (nonpoint pollution source) has not kept up, and nitrate levels are still high.

The fifteen-nation European Union's (EU) Urban Wastewater Treatment Directive has resulted in significant improvements in wastewater treatment capacity and methods. According to the European Environment Agency, increased treatment capacity has been realized in all EU countries except Sweden, Finland, and the Netherlands, where it is already efficient. The largest increase will be in southern Europe and Ireland. As a result, the EU's collection and treatment systems should be able to cope with all organic discharges from most member states by 2005. In Finland and Sweden most of the wastewater was being treated in tertiary plants in the 1980s. see also Abatement; Biosolids; NPDES; Pollution Prevention; WAter Pollution.

aerobic life or processes that require, or are not destroyed by, the presence of oxygen anaerobic a life or process that occurs in, or is not destroyed by, the absence of oxygen

CONSTRUCTED WETLANDS

Constructed wetlands are wetlands that are specially built for the purpose of wastewater treatment and are utilized in place of naturally occurring wetlands. They provide a greater degree of wastewater treatment than natural wetlands, as their hydraulic loadings can be managed as required. Because these wetlands are constructed specifically for wastewater treatment, they should not be included in the juris-dictional group, which avoids the regulatory and environmental entanglement associated with natural wetlands. This is in accordance with Environmental Protection Agency regulations. The treatment process can be either aerobic or anaerobic, depending on whether the wetlands are constructed with an exposed water surface or one with subsurface flow. These wetlands can also be used to remove nitrogen, which is usually not removed during the standard wastewater treatment process. Nitrogen removal is accomplished by the growth of cattails and reeds, which utilize the highly nutrient waste-water and consequently remove nitrogen in the process. Sometimes the cattails and reeds must be harvested to complete the removal process.

Internet Resources

Environmental Protection Agency, Office of Water. (1993). "Constructed Wetlands for Wastewater Treatment and Wildlife Habitat." Available from http://www.epa.gov/ owow/wetlands/construct.

Ohio State University Extension, Food, Agricultural, and Biological Engineering. "Wastewater Treatment Principles and Regulations." Available from http://ohio-line.osu.edu/aex-fact/0768.html.

Raymond Cushman and George Carlson

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