Low-Cost Permeable Reactive Barrier (PRB) System to Treat the Organic Compounds and Nutrients in the Groundwater Contaminated by the Landfill-Leachate

Abstract

When already limited safe groundwater is rapidly contaminated with landfill-leachate, it is a timely need to investigate feasible remediation techniques. In this scenario, Permeable Reactive Barrier (PRB) is a potential groundwater treatment method. If waste materials can be effectively applied as PRB reactive media, the system can be made more economical. This study was focused on a treatment system with two mixed-media PRB models (PRB 1 and PRB 2) connected in series, in which dewatered alum sludge (DAS), washed quarry dust (WQD), washed sea sand (WSS), red soil (RS), bio char (BC) and saw dust (SD) were emplaced in reactive beds, to treat organic compounds and nutrients of leachate-contaminated groundwater. Wastewater parameters were measured in terms of BOD5, COD, NO-3-N , NH3-N , TN, PO 3-4-P and TP. Mean removal efficiencies of BOD5 (88.2+5.7%), COD (84.2+9.6%) and NH3-N (95.6+4.2%) were phenomenal with 13.1 days of pore volume hydraulic retention time (HRT) during an experimental period of 140 days. Reactive material properties were not much affected by the interaction with landfill-leachate, thus no considerable change in the removal efficiencies occurred within 140 days. The treatment efficiency of the present system with two reactors connected in series is greater than that of a single PRB reactor filled with the same reactive materials in the same packing configuration.