Constructed wetlands with horizontal sub-surface flow (HF CWs) have been used for wastewater treatment for more than four decades. HF CWs are used around the world for many types of wastewater, including municipal sewage, agricultural and industrial wastewaters, runoff waters, wastewaters containing endocrine-disrupting chemicals, and landfill leachate.

This book fills a gap in the literature by providing an extensive, worldwide overview of this treatment technology. Special attention is paid to assessing the use of this treatment technology in individual countries and treatment performance of various HF CWs with respect to major pollutants in different types of wastewater.

The book provides a broad base of knowledge, including:

• processes occurring in wetland soils and overlying water
• various types of constructed wetlands for wastewater treatment
• detailed information about design parameters, functioning, operation and maintenance, and costs of HF CWs
• evaluations of treatment efficiency of HF CWs under diverse conditions
• information on the global use of HF CWs for various types of wastewater

The inclusion of case studies from over 50 countries and more than 250 colour photos that illustrate the science makes this an invaluable text.

This book will be useful not only to wetland scientists, teachers, and engineers, but also to landscape planners, ecologists, wastewater-treatment designers and governmental decision-makers.

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.