Natural wetlands have been called 'nature's kidneys' because of their ability to remove contaminants from the water flowing through them. Wetlands are perhaps second only to tropical rain forests in biological productivity; plants grow densely and there is a rich microbial community in the sediment and soil in part supported by the plant roots.
Constructed treatment wetlands are manmade wetlands developed specifically to treat contaminants typically in water that flows through them. They are constructed to recreate, to the extent possible, the structure and function of natural wetlands. Like other phytoremediation approaches, treatment wetlands are self-sustaining (though sometimes optimized with minimal energy input), making them a very attractive option for water treatment compared to conventional treatment systems, especially when lifetime costs are compared.
Based on Technical and Regulatory Guidance Document for Constructed Treatment Wetlands (WTLND-1, 2003), this course describes the physical, chemical, and biological mechanisms operating in wetlands treatment systems; the contaminants to which they apply; the characteristics of sites suitable to treatment in this fashion; and relevant regulatory issues.