A literature review of constructed wetlands : a viable treatment system for acid mine drainage

• Main Author: Attwater, C. J.
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/10800

Wetlands are marsh-like ecosystems exhibiting varying degrees of saturation throughout the year and usually contain a variety of aquatic plants. They have proven capabilities in treating wastewater with physical, chemical and biological processes. Wetlands, especially plant-dominated wetlands, have the capability to remove or convert large quantities of pollutants including suspended solids, metals or excess nutrients by filtration, sedimentation, plant uptake, microbial degradation and other processes. A constructed wetland (CW) is a man-made, engineered, marsh-like area designed and constructed to treat wastewater in the same manner as a natural wetland. It is a practical alternative to mechanical wastewater treatment and water quality requirements, especially in remote areas. Although the treatment of wastewater using CW has been in use for over 40 years, it is not a well-known technology outside of scientific and engineering circles. CW have advantages over mechanical wastewater treatment systems such as simplicity in operation and maintenance and relatively low capital and operating costs. The requirements for a larger land base and a lack of standardized design criteria are two disadvantages to mechanical systems. Case studies from CW systems will illustrate that reductions in concentrations of various metals and sulphates and increased pH can be achieved when acid mine drainage is treated in a constructed wetland.