Removal and Degradation of Pentachlorophenol in Clayey Soil Using Nanoscale Iron Particles

Abstract

The main objective of this study was to investigate the efficiency of nanoscale iron particles (NIPs) to promote the reductive degradation of pentachlorophenol (PCP) in clayey soils. A series of batch experiments was conducted using kaolin as a low permeability clayey soil that was spiked with PCP at 1000 mg/kg and NIPs at different concentrations. Specifically, different contact time (1, 2, 8, 12, 24 and 48h) and different NIPs concentrations (1, 2, 4, 5, 8, 10, 20, 40, 60, 80 and 100 g/L) were investigated. PCP concentrations in supernatant and the residual soil for each test were measured. These results showed that 80 to 98% PCP was removed from the soil within an hour, and PCP reduction was increased from 50 to 78% at 1h contact time to 40 to 90% at 24 h contact time for different NIP concentrations. There was no significant effect of NIPs concentration on the PCP removal; however, the amount of PCP reduction increased with increase in concentration of NIPs with 30% at 1 g/L to 98% at 100 g/L. There appears to be an optimal NIPs concentration beyond which benefits are diminished.