Eco-engineered wetlands: exploring nature-based innovations for sustainable effluent treatment

Eco-engineered constructed wetlands are low-cost, nature-based solutions with low energy requirements, capable of treating diverse effluents. The most recent innovations regarding their design include i) multi-stage hybridization, ii) artificial aeration, iii) bioelectrochemical systems, and iv) advanced treatment units that enable the simultaneous removal of contaminants and favor energy generation, whereas the integration of materials, like biochar, functionalized media, and recycled waste, has resulted in improved pollutant removal through increased sorption capacity and the presence of the microbial activity. Modern CWs can effectively cope with a broad spectrum of contaminants, from organic matter and nutrients to heavy metals, and even address emerging contaminants. The present review aims to provide a targeted overview of eco-engineered wetlands and their crucial role in sustainable and effective effluent treatment by presenting recent innovations in eco-engineered wetlands and linking multi-stage and intensified configurations with advanced substrates and nature-based design principles.