Embedded slow-release materials for the remediation of organic pollutants in groundwater: A review

Groundwater is a critical part of the global water cycle. However, the groundwater around the world has been polluted to varying degrees, with organic pollutants being one of the main sources. Traditional materials used in groundwater remediation often suffer from issues like concentration tailing and rebound, necessitating continuous supply of remedial agents. This review specifically introduces the composition and preparation methods of embedded slow-release materials, with a focus on enumerating and detailing combinations of various encapsulating matrices and active agents, as well as their specific degradation effects on targeted pollutants. As an emerging technology, embedded slow-release materials have an efficacy of several days to several years and can significantly reduce the occurrence of trailing and rebounding organic pollutant concentrations. Additionally, this study discussion addresses the challenges associated with applying slow-release technologies in varying hydrogeological conditions, along with recommendations for integrating these technologies with permeable reactive barriers (PRBs) to overcome these hurdles. This review provides theoretical guidance and technical references for the remediation of organically contaminated groundwater, as well as promotes the development of the field of environmental remediation in a more efficient and sustainable direction.