title: Sequential anaerobic-aerobic biodegradation of 2,3,7,8-TCDD contaminated soil in the presence of CMC-coated nZVI and surfactant.
abstract: Enriched microorganisms in sediment collected from a dioxin-contaminated site in Vietnam (Bien Hoa airbase) were used for examining the effectiveness in biological treatment of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in soil. Four bio-treatments were investigated using a sequential anaerobic (17 weeks) followed by an aerobic (6 weeks) incubation. The maximum removal efficiency was approximately 60% even at an extremely low pH (approx. 3.6) condition. Surfactant Tween-80 was added to enhance the bioavailability of dioxin in two treatments, but it appeared to biostimulate methanogens rather than dechlorinators. As a result, methane production was the highest while the dioxin removal efficiency was the lowest, as compared with the other bio-treatments. Carboxymethylcellulose (CMC) coated on nanoscale zero valent iron (nZVI) surface used in two treatments could prevent the direct contact between bacterial cell surface and nZVI which prevented cell death and lysis, hence enhancing dioxin removal. The presence of CMC--_nZVI in bio-treatments gradually released H2 required for microbiological processes, but the amount used in the experiments were likely too high to maintain optimum H2 levels for biostimulating dechlorinators rather than methanogens.
authors.affiliation: a Environmental Engineering and Management, SERD , Asian Institute of Technology , Pathumthani , Thailand.
authors.forename: Nguyen Duy
authors.initials: ND
authors.lastname: Binh
authors.affiliation: a Environmental Engineering and Management, SERD , Asian Institute of Technology , Pathumthani , Thailand.
authors.forename: Chaiyaporn
authors.initials: C
authors.lastname: Imsapsangworn
authors.affiliation: a Environmental Engineering and Management, SERD , Asian Institute of Technology , Pathumthani , Thailand.
authors.forename: Nguyen Thi
authors.initials: NT
authors.lastname: Kim Oanh
authors.affiliation: a Environmental Engineering and Management, SERD , Asian Institute of Technology , Pathumthani , Thailand.
authors.forename: Preeda
authors.initials: P
authors.lastname: Parkpian
authors.affiliation: a Environmental Engineering and Management, SERD , Asian Institute of Technology , Pathumthani , Thailand.|b Foundation for Scientific & Industrial Research (SINTEF) , Oslo , Norway.
authors.forename: Kare
authors.initials: K
authors.lastname: Karstensen
authors.affiliation: a Environmental Engineering and Management, SERD , Asian Institute of Technology , Pathumthani , Thailand.
authors.forename: Pham Huy
authors.initials: PH
authors.lastname: Giao
authors.affiliation: c Department of Oceanography & Coastal Sciences , Louisiana State University and Agricultural and Mechanical College , Baton Rouge , LA , USA.
authors.forename: Ronald D
authors.initials: RD
authors.lastname: DeLaune
mesh_terms: D001673:Biodegradation, Environmental; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry*; D000072317:Polychlorinated Dibenzodioxins / Q000032:analysis / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000072317:Polychlorinated Dibenzodioxins; D012989:Soil Pollutants; D013501:Surface-Active Agents; D002266:Carboxymethylcellulose Sodium
keywords: carboxymethylcellulose; dioxin; nanoscale ZVI; sequential biodegradation; soil