Harnessing aquatic macrophytes for water pollution remediation through constructed wetlands and future perspectives

Water pollution remains a critical global challenge driven by rapid industrialization, agricultural intensification, and urban expansion. Aquatic macrophyte-based bioremediation has emerged as a sustainable and cost-effective strategy for the treatment of contaminated water systems. This review systematically evaluates the functional classification of macrophytes and elucidates their roles in pollutant removal through mechanisms such as phytoextraction, rhizofiltration, and microbially mediated degradation. Analysis of reported studies indicates that macrophyte-based systems can achieve high removal efficiencies for conventional pollutants, often exceeding 70–90% for nutrients, organic matter, and selected heavy metals under optimized conditions. However, the removal of emerging contaminants, including pharmaceuticals and microplastics, remains variable and largely compound-specific. Operational parameters such as hydraulic retention time, plant density, and environmental conditions are identified as key factors governing treatment performance. Evidence from constructed wetland applications further demonstrates their potential for large-scale wastewater treatment, although challenges related to clogging, seasonal variability, and biomass management persist. Recent advancements integrating nanotechnology, microbial consortia, and hybrid wetland systems show promise in enhancing treatment efficiency. Overall, macrophyte-based systems represent an effective nature-based solution, though their optimization and integration with advanced technologies are essential for addressing complex and emerging pollutants. Aquatic macrophytes exhibit superior nutrient and metal uptake capacity. Integrated phytoremediation mechanisms enable simultaneous removal of nutrients, heavy metals, and organic pollutants. Macrophyte-based systems demonstrate high removal efficiencies for conventional pollutants. Operational and environmental factors influencing remediation and constructed wetlands. Constructed wetlands provide large-scale applicability, but field-scale performance is influenced by hydraulic variability and maintenance constraints. Hybrid approaches integrating macrophytes with nanomaterials, biochar, and AI-based monitoring significantly enhance treatment efficiency.