Environmental Applications of Nanotechnology: Nano-enabled Remediation Processes in Water, Soil and Air Treatment

Environmental remediation is a research field transformed over the past two decades by the integration of engineered nanoscale materials. The market for nanotechnology in environmental applications is rapidly growing, signifying the importance of such advancements in practice as well as research. Most nano-enabled remediation challenges in water, soil and air treatment are addressed by two primary phenomena—contaminant degradation by reduction/oxidation reactions or contaminant sequestration through adsorption processes. Despite the scientific accessibility of these fields by virtue of their shared treatment mechanisms, the unique engineering and physical challenges associated with implementation require field-specific solutions and create research bubbles where scientists and engineers may be unfamiliar with current research in parallel areas. Consequently, this review is focused on summarizing the key nano-enabled technologies and their mechanisms in the fields of water, soil and air treatment, as well as describing recent advances and highlighting areas with clear direction for further development. This review covers nano-enabled processes including photocatalysis in air and water treatment, nZVI-mediated reduction and adsorption processes in soil and water treatment, and CO₂ capture and reduction including the state-of-the-art materials driving research focused on improving these technologies. This review is intended as a platform for researchers to understand how their expertise fits into the larger community of remediation technology as well as to provide direction for literature review of parallel fields suiting their interest. We conclude by identifying core research focuses and underdeveloped research directions in each of the three areas, most notably, a need for guided evaluation of meaningful composite materials for next-generation catalysts.