The investigation of fluorene removal with chemical oxidation after soil washing
DESALINATION AND WATER TREATMENT, vol.93, pp.346-354, 2017 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 93
- Publication Date: 2017
- Doi Number: 10.5004/dwt.2017.21318
- Journal Name: DESALINATION AND WATER TREATMENT
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.346-354
- Keywords: Polycyclic aromatic hydrocarbon (PAH), Soil remediation, Surfactant, Fenton oxidation, POLYCYCLIC AROMATIC-HYDROCARBONS, PAH CONTAMINATED SOIL, FENTON OXIDATION, ELECTROCHEMICAL DEGRADATION, REMEDIATION, EXTRACTION, REAGENT
- Ondokuz Mayıs University Affiliated: Yes
Abstract
Soils contaminated by polycyclic aromatic hydrocarbons (PAHs) pose potential risks to human health and the environment. In this study a combined physical-chemical treatment involving soil washing and advanced oxidation was investigated. A fluorene contaminated loamy soil was treated with a washing solution containing a non-ionic surfactant polyoxyethylene 20 cetyl ether (Brij 58). The washing solution containing fluorene (48.5-54.3 mg/L) was afterwards treated with Fenton and electro-Fenton oxidation. The conventional Fenton oxidation results revealed a fast removal of fluorene (>84%) within the first 15 min. COD removal representing the general destruction of washing solution remained at about 10%, but increased to 81% when the reaction time was increased to 480 min using 2% hydrogen peroxide (H2O2). The corresponding fluorene removal was about 98%. The pseudo-second order rate constants observed for fluorene (0.0016 L/mg min) and COD (1.5 x 10(-6) L/mg min) oxidation supported these results by indicating to a faster oxidation of fluorene. Increase in the H2O2 concentration similarly influenced the oxidation of COD rather than fluorene. The COD removal efficiency increased from 43% to 97% when the H2O2 concentration was increased from 2% to 10% for a treatment time of 120 min. Electro-Fenton oxidation studies with a current density of 15 mA/cm(2) and an electrolyte conductivity of 2 mS/cm revealed even better results enabling a reduction in reaction time. 60 min of reaction time with 2% H2O2 represented removal efficiencies of 98% and 91% for fluorene and COD, respectively.