ABSTRACT
The use of constructed wetlands to treat industrial wastewater is very interesting because its investment, operation, and maintenance cost are low. Constructed wetland is wetland specifically engineered with water quality improvement as its primary purpose, whereas most natural wetlands are parts of water-receiving areas. There are two types of constructed wetlands: free water surface flow (FWS) and subsurface flow (SF). Many researchers studied the use of constructed wetlands for wastewater treatment for direct application to municipal wastewater to reduce biological oxygen demand and concentrations of nitrogen, phosphorus, and suspended solids by 50-60% or more. In addition, those researchers mostly applied floating plants to remove heavy metals from wastewater. Nonetheless, the study of emergent plants is also interesting because the assumption that wastewater comes into contact with emergent plants' rhizospheres as it gradually passes down through the soil. The efficiency of a constructed wetland in treating metals depends on its design and management and some significant components (Dundabin and Bowmer, 1990).
