Constructed wetlands for wastewater management

The rise in the global population has increased the use of freshwater, leading to a worldwide decrease in freshwater volume and quality. Several treatment technologies have been devised and developed to treat polluted water to fulfill the need for water and make it re-usable. Constructed wetlands (CWs) a treatment technology for this purpose in terms of treatment efficiency, ease of operation and maintenance, and cost-effectiveness. CWs are primarily composed of four biotic and abiotic components that perform various physical, chemical, and biological processes to treat pollutants. This chapter discusses the basics of CW components, multiple mechanisms involved in CWs, and the interactions of components of CWs to treat different types of wastewater. In addition, the removal mechanisms of nutrients (i.e., nitrogen, phosphorus, and carbon) from wastewater are highlighted. This chapter also illustrates the cumulative interaction of plant–microbe, microbe–substrate, and substrate–wastewater to treat various types of pollutants. Furthermore, the pros and cons of CWs are elaborated to provide a futuristic approach to treating other complex pollutants (such as emerging pollutants) in wastewater.