Passive in Situ Remediation of Contaminated Ground Water using Permeable Reactive Barrier

Groundwater contamination due to heavy metals, either from natural sources or anthropogenic sources, has become a major concern for the authorities these days. Industrial activities with inadequate and improper water treatment, and then leaching of the same into the water body, make the ground water contaminated and harmful to consume. Passive remediation is one of the recent treatments introduced to counter this problem as it is low in cost but an effective technique. After being widely acknowledged and through research conducted, the most suitable remediation technique found is the permeable reactive barriers (PRBs). PRB is defined as an in situ permeable treatment zone filled with reactive materials, designed to intercept and remediate a contaminant plume under natural hydraulic gradients. There have been many findings made from PRB which can be used to remove contaminants such as heavy metal, chlorinated solvents, carbonates and aromatic hydrocarbons. The most crucial criteria in making a successful PRB is the reactive media used to remove contaminants. The current paper presents an overview of the PRB selective medias that have been used and also the unresolved issue on the long-term performance of PRB. This inexpensive but effective technique is crucial as a sustainable technology in order to treat the drainage before it enters water tables to prevent water pollution and can be used as an alternative raw water source.