Stable isotopic investigations of in-situ bioremediation of chlorinated organic solvents

The contamination by chlorinated organic solvents is a worldwide problem as they can deeply penetrate aquifers, accumulating in the sub-surface as lenses of highly hazardous pollutants. In recent years, so called in situ oxidation processes have been developed to remediate chlorinated organic solvents from groundwater and soil by injecting solutions of oxidising agents such as permanganate or peroxydisulphate. We here present modified layered double hydroxides (LDHs) with intercalated oxidising agents that might serve as new reactants for these remediation strategies. LDHs might serve as support and stabiliser materials for selected oxidising agents during injection, as the uncontrolled reaction and consumption might be inhibited, and guarantee that the selected oxidants persist in the subsurface after injection. In this study, LDHs with hydrotalcite- and hydrocalumite-like structures intercalated with permanganate and peroxydisulphate anions were synthesised and their efficiency was tested in batch experiments using trichloroethene or 1,1,2-trichloroethane as the target contaminants. All samples were characterised using powder X-ray diffraction, thermal analysis coupled with mass spectrometry to directly analyse evolving gases, and Fourier-transform infrared spectroscopy. Additionally, particle size distribution measurements were carried out on the synthesised materials. Results of the batch experiments confirmed the hypothesis that oxidising agents keep their properties after intercalation. Permanganate intercalated LDHs proved to be most efficient at degrading trichloroethene while peroxydisulphate intercalated Ca,Al-LDHs were the most promising studied reactants degrading 1,1,2-trichloroethane. The detection of dichloroethene as well as the transformation of the studied reactants into new LDH phases confirmed the successful degradation of the target contaminant by oxidation processes generated from the intercalated oxidising agent.

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Iron Nanoparticles for In Situ Groundwater Remediation of Chlorinated Organic Solvents in Taiwan

ACS Symposium Series - Environmental Applications of Nanoscale and Microscale Reactive Metal Particles ◽

10.1021/bk-2009-1027.ch013 ◽

2009 ◽

pp. 233-243

Author(s):

Yu-Ting Wei ◽

Shian-Chee Wu ◽

Chih-Ming Chou ◽

De-Huang Huang ◽

Hsing-Lung Lien

Keyword(s):

Organic Solvents ◽

Groundwater Remediation ◽

Iron Nanoparticles ◽

Chlorinated Organic

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In situ bioremediation of cyanide, PAHs and organic compounds using an engineered SEquenced REactive BARrier (SEREBAR)

Land Contamination & Reclamation ◽

10.2462/09670513.755 ◽

2006 ◽

Vol 14 (2) ◽

pp. 478-482

Author(s):

Jamie Robinson ◽

Russell Thomas ◽

Steve Wallace ◽

Paddy Daly ◽

Robert Kalin

Keyword(s):

Organic Compounds ◽

In Situ Bioremediation ◽

Reactive Barrier

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In Situ Bioremediation of Perchlorate in Groundwater

10.21236/ada520589 ◽

2009 ◽

Author(s):

Paul Hatzinger ◽

Jay Diebold

Keyword(s):

In Situ Bioremediation

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On-site and in situ bioremediation of wood-preservative contaminated groundwater

Water Science & Technology ◽

10.2166/wst.2000.0537 ◽

2000 ◽

Vol 42 (5-6) ◽

pp. 371-376 ◽

Cited By ~ 11

Author(s):

J.A. Puhakka ◽

K.T. Järvinen ◽

J.H. Langwaldt ◽

E.S. Melin ◽

M.K. Männistö ◽

...

Keyword(s):

Iron Oxidation ◽

Wood Preservative ◽

Pilot Scale ◽

High Rate ◽

Contaminated Groundwater ◽

Groundwater Temperature ◽

In Situ Bioremediation ◽

Contaminated Aquifer ◽

Fluidized Bed Process

This paper reviews ten years of research on on-site and in situ bioremediation of chlorophenol contaminated groundwater. Laboratory experiments on the development of a high-rate, fluidized-bed process resulted in a full-scale, pump-and-treat application which has operated for several years. The system operates at ambient groundwater temperature of 7 to 9°C at 2.7 d hydraulic retention time and chlorophenol removal efficiencies of 98.5 to 99.9%. The microbial ecology studies of the contaminated aquifer revealed a diverse chlorophenol-degrading community. In situ biodegradation of chlorophenols is controlled by oxygen availability, only. Laboratory and pilot-scale experiments showed the potential for in situ aquifer bioremediation with iron oxidation and precipitation as a potential problem.

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