Inorganic chelated modified-Fenton treatment of polycyclic aromatic hydrocarbon (PAH)-contaminated soils

In this work, the effects of chelating agent (CA) on the removal of phenanthrene (PHE) and fluoranthene (FLUT) from contaminated soil through modified-Fenton (MF) treatment at natural soil pH have been investigated. Chelate enhanced MF treatment resulted in rapid PAH degradation that obeyed pseudo-first-order kinetics with rate constants within the ranges of 9.15 x 10(-2) to 2.30 x 10(-1) min(-1) and 7.20 x 10(-2) to 2.34 x 10(-1) min(-1) for PHE and FLUT respectively. Inorganic CA sodium pyrophosphate (SP) was demonstrated to be superior to commonly employed organic CAs such as ethylene diamine tetraacetic acid, oxalic acid and sodium citrate, and resulted in PAH removal efficiencies of up to 89.13%. The compatibility of SP was also tested for persulphate enhanced oxidation of PAH-contaminated soil. Remarkable oxidative PAN removals (95.41% and 92.25% for PHE and FLUT respectively) were observed in the persulphate-MF treatment which suggested the feasibility of integrated MF reagent in treating PAN-contaminated soil. (C) 2011 Elsevier B.V. All rights reserved.