Remediation of an aged PCP-contaminated soil by chemical oxidation under flow-through conditions

V. Rybnikova (1) , N. Singhal (2) , K Hanna (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 Department of Civil and Environmental Engineering

Pentachlorophenol (PCP) in aged polluted soil was oxidized under water-unsatd. and water-satd. conditions by KMnO4 (PM), potassium persulfate (PS), and H2O2 (HP). Overall, the results of PCP removal and oxidant decompn. indicated that column water content had no significant effect on oxidn. performance. The flow rate increase from 0.025 to 2.5 mL/min decreased oxidant decompn. and extent of PCP degrdn., except for highly reactive HP. In-column kinetic limitations may explain the oxidant residence time effect on degrdn. performance. Consistently, re-circulating oxidant solns. in a closed loop system improved oxidn. efficiency and extent of oxidant decompn. for PS and PM, but not HP. Attempts to enhance the in-soil PCP availability using soly. agents or by heating did not improve in-soil degrdn. efficiency. The presence of methyl-β-cyclodextrin (M-β-CD) only affected the HP decompn. rate, which was pos. correlated with M-β-CD concn. High HP persistence could be advantageous where oxidant delivery to the pollution zone can be limited by its high reactivity. Results may have strong implications for using chem. oxidn. under field conditions, particularly where oxidant injection mode in satd. or unsatd. zones is crucial in detg. remediation performance.

Keywords: Column; Mobilization; Pentachlorophenol; Contaminated soil; Oxidation

Domains: Chemical Sciences; Chemical engineering; Environmental Sciences; Environmental Engineering

V. Rybnikova, N. Singhal, K Hanna. Remediation of an aged PCP-contaminated soil by chemical oxidation under flow-through conditions. Chemical Engineering Journal, 2017, 314, pp.202-211. ⟨10.1016/j.cej.2016.12.120⟩. ⟨hal-01475805⟩