Evaluation of PCB dechlorination pathways in anaerobic sediment microcosms using an anaerobic dechlorination model

2015-10-15
Demirtepe, Hale
Kjellerup, Birthe
Sowers, Kevin R.
İmamoğlu, İpek
A detailed quantitative analysis of anaerobic dechlorination (AD) pathways of polychlorinated biphenyls (PCBs) in sediment microcosms was performed by applying an anaerobic dechlorination model (ADM). The purpose of ADM is to systematically analyze changes in a contaminant profile that result from microbial reductive dechlorination according to empirically determined dechlorination pathways. In contrast to prior studies that utilized modeling tools to predict dechlorination pathways, ADM also provides quantification of individual pathways. As only microbial reductive dechlorination of PCBs occurred in the modeled laboratory microcosms, extensive analysis of AD pathways was possible without the complicating effect of concurrent physico-chemical or other weathering mechanisms. The results from this study showed: (1) ninety three AD pathways are active; (2) tetra- to hepta-chlorobiphenyl (CB) congeners were common intermediates in several AD pathways, penta-CBs being the most frequently observed; (3) the highest rates of dechlorination were for penta-CB homologs during the initial 185 days; (4) the dominant terminal products of AD were PCB 32(26-4), 49(24-25), 51(24-26), 52(25-25), 72(25-35), 73(26-35) and 100(246-24), (5) potential toxicity of the sediment was reduced. ADM serves as a powerful tool not only for a thorough analysis of AD pathways, but also for providing necessary input for numerical fate models (as a degradation term) that investigate dechlorination products or outcome of natural attenuation, or bioremediation/bioaugmentation of PCB-impacted sediments.
JOURNAL OF HAZARDOUS MATERIALS

Suggestions

Estimation of rate constants of PCB dechlorination reactions using an anaerobic dehalogenation model
KARAKAS, Filiz; İmamoğlu, İpek (Elsevier BV, 2017-02-15)
This study aims to estimate anaerobic dechlorination rate constants (k(m)) of reactions of individual PCB congeners using data from four laboratory microcosms set up using sediment from Baltimore Harbor. Pathway km values are estimated by modifying a previously developed model as Anaerobic Dehalogenation Model (ADM) which can be applied to any halogenated hydrophobic organic (HOC). Improvements such as handling multiple dechlorination activities (DAs) and co-elution of congeners, incorporating constraints, ...
Quantum chemical study on 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one (NTO) and some of its constitutional isomers
Türker, Burhan Lemi; Atalar, Taner (Elsevier BV, 2006-10-11)
Presently, certain isomeric compounds of NTO and their tautomers have been investigated by performing density functional theory (DFT) calculations at B3LYP/6-31G(d,p) and ROB3P86/6-311G(d,p) levels and also ab initio calculations at RHF/6-311G(d,p) level. The optimized geometries, vibrational frequencies, electronic structures and some thermodynamical values for the presently considered NTO isomers have been obtained in their ground states. Also, detonation performances were evaluated by the Kammlet-Jacobs ...
Sorption of radioactive cesium and barium ions onto solid humic acid
Celebi, O.; Kilikli, A.; ERTEN, HASAN NİYAZİ (Elsevier BV, 2009-09-15)
In this study, the sorption behavior of two important fission product radionuclides ((137)Cs and (140)Ba) onto sodium form of insolubilized humic acid (INaA) were investigated as a function of time, cation concentration and temperature, utilizing the radiotracer method. The sorption processes are well described by both Freundlich and Dubinin-Radushkevich type isotherms. Thermodynamic constants such as: free energy (Delta G(ads)), enthalpy (Delta H(ads)), entropy (Delta S(ads)) of adsorption were determined....
Potential risk reduction of Aroclor 1254 by microbial dechlorination in anaerobic Grasse River sediment microcosms
Kaya, Devrim; İmamoğlu, İpek; Sanin, Faika Dilek; Payne, Rayford B.; Sowers, Kevin R. (Elsevier BV, 2017-01-05)
Aroclor 1254 was the second most produced commercial PCB mixture and is found in soils, sediments and sewage throughout the globe. This commercial PCB mixture is considered particularly toxic because of the relatively high concentrations of congeners with dioxin-like properties. The potential for risk reduction by microbial reductive dechlorination of Aroclor 1254 (A1254) was investigated in sediment microcosms from Grasse River (GR), Massena, NY. The specificity of A1254 dechlorination was doubly- and sing...
A membrane-based co-treatment strategy for the recovery of print- and beck-dyeing textile effluents
Capar, G.; Yılmaz, Levent; Yetiş, Ülkü (Elsevier BV, 2008-03-21)
This paper describes the final part of a study on the recovery of print- and beck-dyeing wastewaters of the carpet manufacturing industry by membrane processes. These wastewaters had been previously treated separately where the print dyeing wastewaters were recovered by chemical precipitation followed by nanofiltration (NF) and beck-dyeing wastewaters were subjected to microfiltration (MF) and pH neutralization prior to NF. In this study, a co-treatment scheme after separate pre-treatment stages was adopted...
Citation Formats
H. Demirtepe, B. Kjellerup, K. R. Sowers, and İ. İmamoğlu, “Evaluation of PCB dechlorination pathways in anaerobic sediment microcosms using an anaerobic dechlorination model,” JOURNAL OF HAZARDOUS MATERIALS, pp. 120–127, 2015, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/42344.