Low-Cost Sequential Permeable Reactive Barrier (PRB) to Treat Groundwater Contaminated by Landfill-Leachate

Permeable Reactive Barrier (PRB) is an on-site treatment technique, which can be effectively used for remediating the groundwater contaminated by landfill - leachate. The objective of this study was to investigate the applicability of several low – cost/waste materials as the reactive media in a bench-scale sequential PRB model to treat the contaminated groundwater by landfill leachate. There were two bench-scale sequential PRB models as experimental and control. Dewatered alum sludge (DAS), washed quarry dust (WQD), fire-wood charcoal (FWC), sea sand (SS) and saw dust (SD) were placed in the experimental model whereas the control model was filled with red laterite soil (RLS), and commonly used zero valent ion (ZVI) and granular activated carbon (GAC) as vertical equal layers. The target wastewater parameters were organic matter (COD and BOD₅), nitrogenous compounds (NH₃-N, NO₃^--N and TN) and heavy metals (Cd, Cu, and Fe). The overall removal efficiency of BOD₅ and Cd were greater than 90% and almost 100%, respectively. Further, the masses of BOD₅ and TN removed during the entire run of the experimental model were almost the same as those of the control model. Hence, it can be concluded that the low – cost/waste materials used in the experimental model have a potential to be used as reactive media in PRBs aiming at treating the landfill – leachate. Further, this would be a sustainable reuse application for waste materials to be dumped.