The basic mechanisms include sedimentation, chemical precipitation and adsorption, and microbial interactions with BOD L , SS, and N, as well as some uptake by the vegetation. For example, the effluent concentration at Arcata was less than 20 ppm of BOD L . There are limits to the technology of using constructed wetlands for high BOD L wastewater treatment. Constructed wetlands are best used for polishing secondary effluent. The combined system has minimum energy requirements and can be readily implemented without the need for specialized high technology.
Monitoring is required to check performance.
Map of the city of Tlaxiaco, Oaxaca, Mexico.