ABSTRACT
This chapter reviews some models for horizontal subsurface flow constructed treatment wetland systems, starting with simple models like rules of thumb and regression equations then, the well known reaction rate models. Constructed wetlands (CWs) are techniques aim to improve water quality and reduce the harmful effect of effluent. CWs are considered a technical, economical and environmental sustainable solution for wastewater treatment in small communities since they are efficient diverse with pollutants removal. CWs are an innovating technology around the world, which developed over the past few decades, primarily by wetland scientists in Europe and the United States (US). In the US, the most common media for Horizontal subsurface flow (HSSF) CWs is gravel, but sand and soil have been used in Europe. The results of the artificial neural networks and of the models design equations were compared with the available data from the literature, and showed a rather satisfactory performance.
