Phytoremediation of pollutants in constructed wetlands is an eco-friendly, sustainable, and green technology: environmental act, applications, mechanisms, phytotoxicity, fate of phytoremediators, implications, advantages, limitations, and future scopes

Abstract

Phytoremediation, a nature-based solution utilizing green plants, is an environmentally sound and cost-effective technology for the remediation of contaminated environments. Constructed wetlands (CWs) leverage these natural processes in a controlled, engineered environment to effectively treat a wide range of pollutants, including heavy metals, nutrients, organic compounds, and pathogens from municipal, agricultural, and industrial wastewaters. The primary mechanisms involved in CW phytoremediation include phytoextraction, phytostabilization, phytovolatilization, rhizofiltration, phytodegradation, and rhizodegradation. This review article provides a comprehensive overview of the application of phytoremediation in CWs. It details the various mechanisms of pollutant removal and addresses the critical issue of phytotoxicity, where high pollutant concentrations may impact plant survival and efficiency. Furthermore, the review explores the environmental legislation and acts that govern the implementation of such green technologies, the long-term fate of pollutants and the phytoremediators, and the opportunities for resource recovery, like bioenergy production from harvested biomass. The implications, challenges, limitations, slow treatment rates, and the need for proper biomass disposal are discussed alongside prospects, emphasizing the potential for genetic engineering and integration with other technologies to enhance efficiency and sustainability. This synthesis aims to provide valuable insights for researchers, practitioners, and policymakers in advancing sustainable and ecological solutions for environmental cleanup.