Application of constructed wetlands for the safe and sustainable treatment of emerging contaminants

Abstract Researchers are paying increasing attention to emerging contaminant (EC) residues as potential pollutants because they often have physicochemical behavior that is similar to that of other harmful xenobiotics, which can produce adverse effects. Due to their pseudo-persistence and its biological activity, the ECs (including pharmaceuticals and personal care products) are a major concern for the environment. These contaminants are found in very low concentrations, which renders conventional treatment methods inappropriate. However, many other technologies can be used for the treatment of wastewater (WW), one of which is discussed in this chapter. During the past few years, the planned use of wetlands for meeting WW treatment and water-quality objectives has been seriously studied and implemented in a controlled manner. A constructed wetlands (CW) system for a WW treatment facility involves the use of engineered systems that are designed and constructed to use natural processes. These systems mimic natural wetlands systems by using wetlands plants, soils, and associated microorganisms to remove contaminants from WW effluents. Various research carried out during the last few decades on the performances of the wetlands in treating WW has provided quantitative information that has been used to improve the process's efficiency through design and operation measures. The removal of emerging pollutants in these wetlands systems relies on a combination of physical, chemical, and biological processes that naturally occur in wetlands that are associated with vegetation, sediments, and their microbial communities. CW systems for WW treatment have been proven to be effective, low-cost, and sustainable alternatives to conventional WW treatment technologies.