In the field of wastewater treatment, energy-intensive and highly mechanize
d technologies are giving way to nature-based technologies that utilize sol
ar energy and living organisms. Constructed treatment wetland (CTW) technol
ogy has played an important role in bringing about the change. Wetland tech
nology can provide cheap and effective wastewater treatment in both tempera
te and tropical climates, and are suitable for adoption in both industriali
zed as well as developing nations. Currently, CTWs are being utilized for r
emoval of a range of pollutants and a broad variety of wastewaters worldwid
e. The objective of this article is to provide a comprehensive review of th
e CTW technology and to present the pollutant removal performance experienc
es gathered through the application of this technology around the world.