Eco-Friendly Nanomaterials for Remediation of Microplastics and Heavy Metals in Wetland Ecosystems

Microplastics (MPs) and heavy metals (HMs) are pervasive contaminants in wetland ecosystems, where their co-occurrence poses complex ecological and human health risks due to synergistic interactions. Traditional remediation strategies often target these pollutants separately, overlooking opportunities for integrated removal approaches. This review addresses the research gap by systematically synthesizing current knowledge on eco-friendly nanomaterials for simultaneous MP–HM remediation in wetlands, with a particular focus on sustainable, low-cost solutions suitable for resource-limited contexts. Following PRISMA guidelines, over 50 peer-reviewed studies were analyzed to assess nanomaterial types, physicochemical properties, contaminant removal mechanisms, and integration into wetland systems. Key findings reveal that bio-based and green-synthesized nanomaterials such as biochar composites, metal–organic frameworks, and plant-derived nanoparticles show promising efficiency in MP–HM co-remediation, while maintaining compatibility with wetland biota. Design considerations, operational challenges, and policy frameworks are critically discussed, alongside identified knowledge gaps, including limited field-scale validation and long-term ecological risk assessments. The review concludes with targeted recommendations for future research, emphasizing scalable nanomaterial development, optimized wetland-nanomaterial synergy, and inclusion of MP–HM co-remediation in environmental policy. This synthesis offers a unique, integrated perspective that bridges material science, wetland ecology, and environmental management to advance sustainable remediation strategies in the face of complex contaminant mixtures.