Phytoremediation using Aquatic Plants

Freshwaters are affected by a diverse range of pollutants which increase the demand for effective remediation. Aquatic phytoremediation is a nature-based solution that has the potential to provide efficient, spatially adaptable and multi-targeted treatment of polluted waters using the ability of macrophytes to take-up, sequester and degrade pollutants. This chapter considers the primary phytoremediation mechanisms that macrophytes employ to remove inorganic, organic and biological waterborne pollutants before highlighting some of the common macrophyte accumulators that have been studied. Three common macrophyte planting systems (i) constructed wetlands (CWs), (ii) wild macrophyte planting/harvesting and (iii) floating treatment wetlands (FTWs) are considered to understand how macrophytes are deployed for targeted aquatic phytoremediation. Important practical considerations for implementing aquatic phytoremediation include the use of invasive species, the optimal harvesting time and frequency for pollutant removal with macrophyte biomass, and the full extent of the role that microbial biofilms play in phytoremediation. In this chapter, these issues are unpacked and recommendations for future programmes of research and development are made. Finally, the opportunities to generate ‘added value’ from expanding aquatic phytoremediation in terms of the provision of ecosystem services and the potential for resource recovery are outlined.