This chapter follows a designer and analytical approach of wetland systems, specifically global constructed wetlands and treatment wetlands, in continuation with our discussion in Chapter 4. The diverse designs of constructed wetland systems (free water surface [FWS], HF, VF, and hybrid) and existing benefits and constraints are discussed from a global perspective pertaining to the remediation of emerging contaminants. Thus, this chapter describes the designer approach used in pollution science to assess the water quality of wetlands, which is inextricably linked with wetland management. Further, water quality parameters of treatment wetlands remarkably affect the concentration, as well as phytoremediation mechanism, of emerging contaminants, like heavy metals and organics. Since water quality affects not only the availability, and hence toxicity, of emerging contaminants but also the phytoremediation potential of wetland plants, this discussion is quite relevant. To this end, the methodologies to evaluate the water quality or physicochemical parameters are briefly mentioned. Further, it is well known that instrumentation technologies have made remarkable advances or innovations in assessing emerging contaminants in wetland environments and also characterizing the nanoparticles (NPs) and nanomaterials that exist in different environmental compartments.