Analysis of clogging failure modes in permeable reactive barriers (prbs) during groundwater remediation of landfill contamination

Groundwater is a crucial component of water resources, yet the situation of groundwater pollution in China is severe, with municipal solid waste landfills being one of the primary sources of contamination. Permeable reactive barriers (PRBs), a passive in-situ remediation system, offer numerous advantages in treating groundwater contaminated by landfills but are prone to clogging issues. This study examines the clogging problem in PRBs during the remediation of contaminated groundwater from both exogenous and endogenous particulate perspectives, exploring the clogging patterns of PRBs. It reveals that the sources and particle sizes of solids/flocs in contaminated groundwater are diverse, with minimal retention by the site's permeable layer. These particles are adsorbed and intercepted by the PRB, while the interaction between contaminated groundwater and PRB fill materials generates new solids/flocs, which deposit or adhere within the pores of the reactive materials, reducing the permeability of the PRB. PRB clogging failure is often the result of the combined effects of exogenous and endogenous particulate clogging, closely related to the pore structure of the PRB materials.