Coupled electrokinetic and biological remediation method leads to improved treatment of chlorinated solvents at high sulfate, transport limited sites

2020 ◽  
Vol 6 (10) ◽  
pp. 2926-2937
Author(s):  
Megan Meinel ◽  
Rosa Krajmalnik-Brown ◽  
César I. Torres
Keyword(s):  
Chlorinated Solvents ◽  
Sulfate Transport ◽  
Biological Remediation ◽  
High Sulfate

The combined biotic and abiotic mechanisms of EK-Bio can result in improved remediation of TCE over traditional bioaugmentation methods.

Cometabolism in biofilm reactors

1995 ◽  
Vol 31 (1) ◽  
pp. 215-225 ◽  
Author(s):  
Gerald E. Speitel ◽  
Robert L. Segar
Keyword(s):  
Chlorinated Solvents ◽  
Packed Bed ◽  
Operating Conditions ◽  
Mixed Cultures ◽  
Treatment Technology ◽  
Hydraulic Residence Time ◽  
Slow Growth Rate ◽  
Biofilm Reactors ◽  
Aerobic Cometabolism ◽  
Degrading Bacteria

Aerobic cometabolism of chlorinated aliphatic solvents in biofilm reactors is a potential treatment technology for contaminated water and air streams. This research investigated cometabolism by pure and mixed cultures of methanotrophs and mixed cultures of phenol-degrading bacteria. Initial experiments with continuous-flow, packed-bed bioreactors proved unsuccessful; therefore, the major focus of the work was on sequencing biofilm reactors, which cycle between two modes of operation, degradation of chlorinated solvents and rejuvenation of the microbial population. Particular success was obtained with a mixed culture of phenol degraders in the treatment of chlorinated ethenes (e.g., trichloroethylene - TCE). Under the best operating conditions, 90% removal of TCE occurred at a 14-minute packed-bed hydraulic residence time. The bioreactors required only two, 1.5 h biomass rejuvenation periods per day to sustain this removal. Experiments with Methylosinus trichosporium OB3b were less successful because of the organism's slow growth rate, relatively poor ability to attach to surfaces, and its inability to successfully compete with other methanotrophs in the bioreactor environment. Overall, however, the research demonstrated the potential attractiveness of sequencing biofilm reactors in treating water contaminated with chlorinated solvents.

Novel biological removal of hazardous chemicals at trace levels

2000 ◽  
Vol 42 (12) ◽  
pp. 49-60 ◽  
Author(s):  
P.L. McCarty
Keyword(s):  
Plug Flow ◽  
Chlorinated Solvents ◽  
Biological Removal ◽  
Sanitary Landfills ◽  
Low Levels ◽  
Trace Chemicals ◽  
Engineered Systems ◽  
Biological Methods ◽  
Aerobic And Anaerobic ◽  
Flow Treatment

Of recent concern is the removal of toxic compounds in wastewaters, soils, and groundwater to concentrations in the low microgram per litre level or less. Threshold limits to bioremediation exist and must be considered in biological treatment schemes to achieve such limits. These limits may be related to reaction kinetics or thermodynamics. Techniques for removing compounds below threshold levels exist that rely on appropriate approaches such as plug flow treatment. Novel biological methods exist for removal of refractory contaminants to low levels. Examples are provided for removal of trace levels of chlorinated solvents, such as tetrachloroethene (PCE) and trichloroethene (TCE), that employ dehalorespiration under anaerobic conditions or cometabolism under aerobic conditions. These approaches are currently being used in engineered systems or through natural attenuation for remediation of soils and groundwater. Successful results offer insights for similar removals of trace chemicals in both aerobic and anaerobic biological systems for treatment of wastewaters and sanitary landfills.

Determination of base number in lubricants and additives by ASTM D2896: Substitution of chlorinated solvents and alternate electrolyte study

Fuel ◽  
2021 ◽  
Vol 297 ◽  
pp. 120701
Author(s):  
Moumita Dutta ◽  
Annie Pathiparampil ◽  
Joshua Murella ◽  
Dominique Villacarte ◽  
Duane Hamada ◽  
...  
Keyword(s):  
Chlorinated Solvents ◽  
Base Number

scholarly journals A Microcosm Treatability Study for Evaluating Wood Mulch-Based Amendments as Electron Donors for Trichloroethene (TCE) Reductive Dechlorination

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1949
Author(s):  
Edoardo Masut ◽  
Alessandro Battaglia ◽  
Luca Ferioli ◽  
Anna Legnani ◽  
Carolina Cruz Viggi ◽  
...  
Keyword(s):  
Electron Donor ◽  
Environmental Sustainability ◽  
Reductive Dechlorination ◽  
Environmental Remediation ◽  
Low Cost ◽  
Chlorinated Solvents ◽  
Electron Donors ◽  
Chlorinated Ethenes ◽  
Dehalococcoides Mccartyi ◽  
Wood Mulch

In this study, wood mulch-based amendments were tested in a bench-scale microcosm experiment in order to assess the treatability of saturated soils and groundwater from an industrial site contaminated by chlorinated ethenes. Wood mulch was tested alone as the only electron donor in order to assess its potential for stimulating the biological reductive dechlorination. It was also tested in combination with millimetric iron filings in order to assess the ability of the additive to accelerate/improve the bioremediation process. The efficacy of the selected amendments was compared with that of unamended control microcosms. The results demonstrated that wood mulch is an effective natural and low-cost electron donor to stimulate the complete reductive dechlorination of chlorinated solvents to ethene. Being a side-product of the wood industry, mulch can be used in environmental remediation, an approach which perfectly fits the principles of circular economy and addresses the compelling needs of a sustainable and low environmental impact remediation. The efficacy of mulch was further improved by the co-presence of iron filings, which accelerated the conversion of vinyl chloride into the ethene by increasing the H2 availability rather than by catalyzing the direct abiotic dechlorination of contaminants. Chemical analyses were corroborated by biomolecular assays, which confirmed the stimulatory effect of the selected amendments on the abundance of Dehalococcoides mccartyi and related reductive dehalogenase genes. Overall, this paper further highlights the application potential and environmental sustainability of wood mulch-based amendments as low-cost electron donors for the biological treatment of chlorinated ethenes.

scholarly journals Fluorescing Layered Double Hydroxides as Tracer Materials for Particle Injection during Subsurface Water Remediation

2020 ◽  
Vol 4 (3) ◽  
pp. 53
Author(s):  
Karen Maria Dietmann ◽  
Tobias Linke ◽  
Markus Reischer ◽  
Vicente Rives
Keyword(s):  
Layered Double Hydroxides ◽  
Chlorinated Solvents ◽  
Cost Effective ◽  
Water Remediation ◽  
Subsurface Water ◽  
Particle Injection ◽  
Global Issue ◽  
Cost Effective Method ◽  
Co Precipitation ◽  
Double Hydroxides

Nowadays, the contamination of groundwater and soils by highly hazardous and toxic chlorinated solvents is a global issue. Over the past years, different remediation strategies have been developed, involving injection of reactive solutions and/or particles. However, a major difficulty is the monitoring of injected particles during the injection and after secondary mobilisation by groundwater flow. This study is focussed on the development of directly traceable particles by combining fluorescein with Layered Double Hydroxides (LDHs). We present here the facile and easily tuneable synthesis of fluorescing LDHs (Fluo-LDH) via co-precipitation under supersaturation conditions. Their ability to mimic particle sizes of previously studied reactive LDHs, which proved to be able to adsorb or degrade chlorinated organic solvents from aqueous solutions, was investigated as well. Tests using a novel Optical Image Profiler (OIP) confirmed that the fluorescent LDHs can be easily detected with this tool. Even LDHs with the lowest amount of fluorescent dye were detectable. Together with the use of an OIP, which is capable of exciting the fluorescent material and collecting real-time pictures, this can provide a new, efficient, and cost-effective method for in situ tracing of injected particles in the subsurface.

Improved electroimmunoassay of factor VIII-related antigen.

1977 ◽  
Vol 23 (3) ◽  
pp. 602-603 ◽  
Author(s):  
A Chute ◽  
J E Haddow ◽  
R F Ritchie
Keyword(s):  
Factor Viii ◽  
Major Part ◽  
Sulfate Content ◽  
Factor Viii Related Antigen ◽  
Factor Viii Antigen ◽  
High Sulfate

Abstract Factor VIII-related antigen migrates poorly into gel during electrophoresis in agarose, probably in major part because of the relatively high sulfate content of the commonly used agars. A recently available low-sulfate residue agar, substituted for standard agar preparations in electroimmunoassay, allows Factor VIII antigen to travel more rapidly, producing "rockets" that are well defined and easily measured, making the assay easier and more reliable.

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