Permeable Reactive Barriers (PRBs) for Environmental Site Remediation

Abstract

Permeable reactive barriers (PRBs) have evolved in the last 25 years from an emerging to a developed technology for in situ groundwater remediation. A PRB involves the emplacement of reactive media perpendicular to the direction of groundwater flow in order to intercept the contaminant plume under natural hydraulic gradients. Owing to their passive nature, PRBs have become a cost-effective alternative to ex situ technologies as they involve no operational and maintenance costs. The cost-effectiveness of a PRB system will depend mainly on the longevity of the reactive media and the long-term hydraulic capture of a system. Further work needs to be carried out to deepen insight into issues related to the ageing of the PRB systems. Knowledge gained over the last two decades has allowed several potential areas for improvement to be identified. The development of novel materials and improvements in construction and monitoring methods will result in a reduction in costs and mitigation of the environmental impact. This chapter attempts to provide a general overview of PRB technology, focusing on the emerging aspects and the future of the technology.