Since their inception, constructed wetlands (CW) have demonstrated significant efficiency in wastewater treatment. These engineered ecosystems represent a relevant model of nature-based solutions and provide a sustainable and effective method for water treatment. They can be applied to various types of wastewaters and integrated at multiple stages of the treatment process. This promising approach offers a low-cost, energy-efficient and ecological method alternative to conventional water treatment system. As a key component of constructed wetlands, the substrate plays a crucial role in water purification. Therefore, selecting the most suitable substrate has garnered significant attention in research. Several studies have suggested using a natural, carbon-rich substrate as the filter medium. In this context, as part of the Horizon Europe MAR2PROTECT project (GA 101082048), the main goal of this study is to enhance constructed wetland (CW) efficiency for removing contaminants from wastewater to be valorised and reused for aquifer recharge.