Silver as an emerging pollutant: A sustainable remediation perspective with nanoparticles and biochar nanocomposites

The rapid advancement of industrialization, urbanization and nanotechnology has intensified environmental contamination by silver (Ag), positioning it as emerging inorganic pollutant (EIP) of global concern. Silver as ions (Ag + ) and nanoparticles (AgNPs) exhibit high mobility and toxicity, disrupting soil microbial communities, impairing crop productivity, and entering into aquatic systems and food chains pose significant risks to ecosystem system and human health. The environmental behavior of Ag is governed by interaction with organic matter, pH and mineral composition, complexation and redox transformations, complicating its remediation. Conventional remediation methods (precipitation, filtration, phytoremediation) remain limited by high cost, low selectivity, longer time and risk of secondary pollution. In contrast, biochar-based nanocomposites (BNCs) integrate the high surface area and adsorption capacity of biochar with the catalytic reactivity of nanoparticles (NPs), enabling efficient Ag + immobilization and toxicity reduction while improving soil fertility and plant resilience. This review synthesizes recent insights into Ag toxicity, transformation, and bioaccumulation across soil–plant–water–human systems. We critically assess their efficacy, limitations, and implementation challenges, and propose integrative strategies that couple advanced materials with ecological restoration principles. By consolidating emerging evidence and highlighting future research needs such as field-scale validation, standardized toxicity protocols, cos-benefit analysis and green synthesis, this work provides a scientific foundation for sustainable remediation of Ag pollution and its integration into global environmental management framework. • Silver (Ag) identified as an emerging inorganic pollutant with complex fate, toxicity, and ecological health risks. • Ag and AgNPs disrupt soil microbiomes, impair plant physiology, and threaten food safety. • Conventional remediation remains costly, inefficient, and prone to secondary pollution. • Biochar–nanocomposites offer sustainable Ag immobilization, soil recovery, and improved plant resilience.