Stability of multi-permeable reactive barriers for long term removal of mixed contaminants.

The Permeable Reactive Barriers (PRBs) are relatively simple, promising technology for groundwater remediation. A PRBs consisting of two reactive barriers (zero valent iron-barrier and bio-barrier) were designed to evaluate the application and feasibility of the barriers for the removal of wide range of pollutants from synthetic water. After 470 days of Multi-PRBs column operation, the pH level in the water sample is increased from 4 to 7, whereas the oxidation reduction potential (ORP) is decreased to -180 mV. Trichloroethylene (TCE), heavy metals, and nitrate were completely removed in the zero valent iron-barrier. Ammonium produced during nitrate reduction is removed in the biologically reactive zone of the column. The results of the present study suggest that Multi-PRBs system is an effective alternate method to confine wide range of pollutants from contaminated groundwater.