Constructed Wetlands Treatment Of High Nitrogen Landfill Leachate

Both practical and theoretical, this book provides the basic principles of soil chemistry, hydrology, wetland ecology, microbiology, vegetation and wildlife as a sound introduction to this innovative technology to treat toxic wastewaters and sludges. The use of wetlands for acid mine drainage, and metals removal in municipal, urban runoff, and industrial systems is discussed. Case histories are also presented, demonstrating specific types of constructed wetlands and applications to municipal wastewater, home sites, coal and non-coal mining, coal-fired electric power plants, chemical and pulp industry, agriculture, landfill leachate, and urban stormwater. Construction and management guidelines are clearly explained, providing information on applicable policies and regulations, siting and construction, and operations and monitoring of constructed wetlands treatment systems. Recent theoretical and empirical results from operating systems and research facilities, including such new applications as nutrient removal from eutrophic lakes and urban stormwater treatment within highway rights-of-way, are included. This book is an ideal resource for wastewater treatment plants, consulting engineers, federal and state regulators, industrial environmental managers, municipalities, environmental health professionals, and ecologists.

Wetlands have been used for uncontrolled wastewater disposal for centuries. However, the change in attitude towards wetlands during the 1950s and 1960s caused the minimization of the use of natural wetlands for wastewater treatment (at least in developed countries). Constructed wetlands have been used for wastewater treatment for about forty years. Constructed wetland treatment systems are engineered systems that have been designed and constructed to utilize the natural processes for removal of pollutants. They are designed to take advantage of many of the same processes that occur in natural wetlands, but do so within a more controlled environment. The aim of this book is to summarize the knowledge on horizontal s- surface flow constructed wetlands (HF CWs) and objectively evaluate their treatment efficiency under various conditions. The information on this type of wastewater treatment technology is scattered in many publications but a comprehensive summary based on world-wide experience has been lacking. The book provides an extensive overview of this treatment technology around the world, including examples from more than 50 countries and examples of various types of wastewater treated in HF CWs.

The aim of this book is to present an overview of the state of the art with regard to the function, application and design of TWSs in order to better protect surface water from contamination. Accordingly, it also presents applications of constructed wetlands with regard to climatic and cultural aspects. The use of artificial and natural treatment wetland systems (TWSs) for wastewater treatment is an approach that has been developed over the last thirty years. Europe is currently home to roughly 10,000 constructed wetland treatment systems (CWTSs), which simulate the aquatic habitat conditions of natural marsh ecosystems; roughly 3,500 systems are in operation in Germany alone. TWSs can also be found in many other European countries, for example 200 – 400 in Denmark, 400 – 600 in Great Britain, and ca. 1,000 in Poland. Most of the existing systems serve as local or individual household treatment systems. CWTSs are easy to operate and do not require specialized maintenance; further, no biological sewage sludge is formed during treatment processes. As TWSs are resistant to fluctuations in hydraulic loads, they are primarily used in rural areas as well as in urbanized areas with dispersed habitats, where conventional sewer systems and central conventional wastewater treatment plants (WWTPs) cannot be applied due to the high costs they would entail. TWSs are usually applied at the 2nd stage of domestic wastewater treatment, after mechanical treatment, and/or at the 3rd stage of treatment in order to ensure purification of effluent from conventional biological reactors and re-naturalization. New applications of TWSs include rainwater treatment as well as industrial and landfill leachate treatment. TWSs are well suited to these fields, as they can potentially remove not only organic matter and nitrogen compounds but also trace metals and traces of persistent organic pollutants and pathogens. Based on the practical experience gathered to date, and on new research regarding the processes and mechanisms of pollutant removal and advances in the systems properties and design, TWSs continue to evolve.

This manual discusses the capabilities of constructed wetlands, a functional design approach, and the management requirements to achieve the designed purpose. The manual also attempts to put the proper perspective on the appropriate use, design and performance of constructed wetlands. For some applications, they are an excellent option because they are low in cost and in maintenance requirements, offer good performance, and provide a natural appearance, if not more beneficial ecological benefits. In other applications, such as large urban areas with large wastewater flows, they may not be at all appropriate owing to their land requirements. Constructed wetlands are especially well suited for wastewater treatment in small communities where inexpensive land is available and skilled operators hard to find and keep. Primary customers will be engineers who service small communities, state regulators, and planning professionals. Secondary users will be environmental groups and the academics.