Emerging Contaminants in Aquatic Environments: Sources, Detection, Toxicity, and Remediation

Aquatic ecosystems worldwide are increasingly threatened by the continuous release of emerging contaminants (ECs), a diverse group of chemical and biological substances that are not routinely monitored but pose significant risks to environmental and human health. These contaminants include pharmaceuticals, personal care products (PPCPs), endocrine-disrupting chemicals (EDCs), per- and polyfluoroalkyl substances (PFAS), microplastics, nanomaterials, pesticides, antibiotic resistance genes (ARGs), industrial chemicals, and artificial sweeteners. Conventional wastewater treatment plants are often unable to completely remove these contaminants, leading to their accumulation in surface water, groundwater, sediments, and aquatic organisms. Long-term exposure to ECs can induce endocrine disruption, reproductive abnormalities, neurotoxicity, oxidative stress, antimicrobial resistance, biodiversity loss, and ecosystem dysfunction. Recent advances in analytical chemistry, particularly chromatography coupled with mass spectrometry, biosensors, nanotechnology, and artificial intelligence-assisted monitoring, have significantly improved the detection and quantification of ECs at trace concentrations. Simultaneously, innovative remediation technologies, including adsorption, advanced oxidation processes, photocatalysis, membrane filtration, constructed wetlands, biochar-based materials, nanomaterials, and bioremediation, have demonstrated considerable potential for removing ECs from aquatic systems. This review discusses the major sources, classification, occurrence, detection techniques, environmental toxicity, remediation strategies, current challenges, and future perspectives of emerging contaminants in aquatic environments.