Environmental applications and risks of nanomaterials: An introduction to CREST publications during 2018-2021

Nanomaterials (NMs) possess many unique properties that are increasingly used in environmental applications. Twenty-six articles in Critical Reviews in Environmental Science and Technology (CREST) from 2018 to 2021were identified that enhance our understanding and provide insight about future research directions with NMs in the environment. The first section focuses on environmental applications of NMs, including sensors to detect contaminants and environmental conditions, novel membrane materials to treat water and wastewater, and nano-enabled remediation of contaminants by adsorption, photocatalytic degradation, and/or disinfection. The second section reports on risks and the fate of NMs in the environment, including mechanisms and models of environmental transport, the role of nanoscale heterogeneities on particle attachment, and contaminant associations and ecotoxicity. The final section discusses research pertaining to emerging applications and ecotoxicity associated with nanosulfur and nanoplastics. This virtual article collection demonstrates that recent nanotechnology advances show great promise for addressing many critical challenges in environmental science and technology. However, many of these studies have been conducted under highly idealized laboratory conditions and still need to be upscaled. Caution is warranted and new approaches are still needed to detect and control the mobility of NMs, and to quantify potential impacts on ecosystems under realistic field conditions.