Application of zeolites in permeable reactive barriers (PRBs) for in-situ groundwater remediation: A critical review

Permeable reactive barrier (PRB) is one of the most promising in-situ groundwater remediation technologies due to its low costs and wide immobilization suitability for multiple contaminants. Reactive medium is a key component of PRBs and their selection needs to consider removal effectiveness as well as permeability. Zeolites have been exten-sively reported as reactive media owing to their high adsorption capacity, diverse pore structure and high stability. Moreover, the application of zeolites can reduce the PRBs fouling and clogging compared to reductants like zero -valence iron (ZVI) due to no formation of secondary precipitates, such as iron monosulfide, in spite of their reac-tivity to remove organics. This study gives a detailed review of lab-scale applications of zeolites in PRBs in terms of sorption characteristics, mechanisms, column performance and desorption features, as well as their field-scale ap-plications to point out their application tendency in PRBs for contaminated groundwater remediation. On this basis, future prospects and suggestions for using zeolites in PRBs for groundwater remediation were put forward. This study provides a comprehensive and critical review of the lab-scale and field-scale applications of zeolites in PRBs and is expected to guide the future design and applications of adsorbents-based PRBs for groundwater remediation.

Automated summary

Permeable reactive barrier (PRB) is a promising groundwater remediation technology with low costs and wide immobilization suitability. Zeolites, as reactive media, have high adsorption capacity, diverse pore structure, and high stability, making them a popular choice. Compared to other reductants, zeolites reduce fouling and clogging in PRBs. This study reviews the lab-scale applications of zeolites in PRBs and presents future prospects and suggestions for their use in groundwater remediation.