Environmental biotechnology, such as bioremediation and phytoremediation, is a promising field that uses natural resources, including microorganisms and plants, to eliminate toxic organic contaminants from water, soils and air (Calheiros et al. 2020). This technology offers an attractive alternative to other conventional remediation processes due to its relatively low cost and environmentally friendly method. In this project, we used floating treatment wetland (FTW), an effective and sustainable technology for wastewater treatment. This method has been widely adopted for the treatment of various types of polluted waters, including agricultural runoff, stormwater, and industrial effluents. In FTWs, plants are vegetated on a floating mat while their roots are extended into contaminated water, acting as biological filters. Nutrients and potentially toxic metals/elements are absorbed from wastewater by plants through their roots, while organic matter is degraded by microorganisms forming biofilms on the roots and on the surface of the mat (Shahid et al. 2018). Thereby, in the present study it was implemented 4 FTW prototypes, of different materials and in different environments (marine and freshwater) to compare their efficiency and establishment on site.info:eu-repo/semantics/publishedVersio