Fundamentals of floating treatment wetlands: Functions, design, and maintenance

Abstract

Floating treatment wetlands (FTWs) are among the nature-based solutions for purifying surface water bodies (e.g., rivers, ponds, and lakes) contaminated by diffuse pollution sources. Different from conventional constructed wetlands, FTWs are composed of emergent macrophytes growing on floating mats on the water surface, thus the systems can withstand various water depths minimum at 0.8-1.0 m. The root systems hang underneath the floating mat, creating a vast surface area for biofilm adhesion. FTWs are becoming popular as a treatment method due to their strong capacity to remove organics, nutrients, heavy metals, and contaminants of emerging concerns (CECs) such as antibiotics, pesticides, and hormones without the need for land. FTWs efficiently treat industrial, municipal, and agricultural wastewater, stormwater runoff, and landfill leachate. This chapter overviews the functions, design, operation, and maintenance recorded of FTWs so far, and highlights the operational performance of FTWs applied for various types of wastewater treatment.