scholarly journals Contamination of Chalk Groundwater by Chlorinated Solvents: A Case Study of Deep Penetration by Non-Aqueous Phase Liquids

1996 ◽  
Vol 10 (4) ◽  
pp. 263-272 ◽  
Author(s):  
A. R. Lawrence ◽  
M. E. Stuart ◽  
J. A. Barker ◽  
D. J. Tester
Keyword(s):  
Aqueous Phase ◽  
Chlorinated Solvents ◽  
Deep Penetration

scholarly journals Assessment of Intrinsic Biodegradation Potentials in an Aquifer Contaminated with Chlorinated Ethenes in the Vicinity of Nowa Deba

2013 ◽  
Vol 20 (2) ◽  
pp. 265-278 ◽  
Author(s):  
Aleksandra Kiecak ◽  
Ewa Kret ◽  
Monika Cichostępska ◽  
Grzegorz Malina
Keyword(s):  
Risk Reduction ◽  
Natural Attenuation ◽  
Chlorinated Solvents ◽  
Fate And Transport ◽  
Site Specific ◽  
Preliminary Screening ◽  
Natural Processes ◽  
The Us ◽  
Time Frames

Abstract Natural Attenuation (NA) in the case of groundwater contaminated with organic compounds relies mainly on intrinsic biodegradation processes. The aim of reliance on natural processes is to achieve site-specific cleanup objectives within reasonable time frames and costs. Such approach may be considered as a risk reduction/remedial option for groundwater contaminated with trichloroethene (TCE) and tetrachloroethene (PCE). This case study presents implementation of the US EPA’s guideline „Technical protocol for evaluating natural attenuation of chlorinated solvents in groundwater” to asses intrinsic biodegradation potentials in TCE and PCE contaminated groundwater in the vicinity of Nowa Deba waterworks (south-east Poland). Literature and field data collected from wells and piezometers were used to develop a conceptual model of contaminants’ fate and transport from a source to a receptor. The intrinsic biodegradation was investigated basing on available analytical parameters (eg concentrations of oxygen, nitrates, chlorides, and pH, TOC and temperature) that are considered as indicators of TCE and PCE transformation. Preliminary screening was done by giving certain points for these parameters, and interpreted in order to asses intrinsic biodegradation potentials. The results indicate inadequate evidence for intrinsic biodegradation (reductive dehalogention) of TCE and PCE, thus a limited potential for NA as a remedial/risk reduction option in the studied case, unless some measures for enhancement of TCE and PCE intrinsic biodegradation are applied.

Large Liquid Volume Deep Penetration Acidizing in Iraq Missan Oilfield - 3 Case Study

2019 ◽  
Author(s):  
Jichao Gao ◽  
Puyong Feng ◽  
Da Wang ◽  
Shangqi Shao ◽  
Bo Cui ◽  
...  
Keyword(s):  
Liquid Volume ◽  
Deep Penetration

scholarly journals Hydrogeochemical and hydrodynamic features affecting redox processes in groundwater

2019 ◽  
Vol 8 (3) ◽  
Author(s):  
Diego Di Curzio
Keyword(s):  
Reductive Dechlorination ◽  
Chlorinated Solvents ◽  
Organic Substrate ◽  
Electron Acceptors ◽  
Contaminated Site ◽  
Hydrodynamic Effect ◽  
Redox Processes ◽  
Dispersive Transport ◽  
Factorial Kriging

This research deals with some hydrogeochemical and hydrodynamic features that affect redox processes in groundwater, presenting three different case studies and methodological approaches. This information is vital when characterizing contaminated sites, planning monitoring, selecting remedial techniques, and assessing health risks. In the San Pedro Sula site case study (Honduras), new insights and an advanced method for the aquifer redox zonation were provided. The Multi-Collocated Factorial Kriging, a multivariate geostatistical technique borrowed from agriculture and soil science, identified simultaneous redox processes, acting at different scales and mainly due to eutrophicated surface-water/groundwater interaction: at short-range, Mn oxihydroxide reductive dissolution and Fe oxi-hydroxide colloidal phase precipitation; at long-range, Fe mobilization. The obtained results are supported by the Principal Component Analysis and hydrogeochemical numerical modeling. The interaction among different contamination events in the VR site allowed to get a deeper insight into the competition for organic substrate among different redox processes. To this purpose, a 1-D Advective-Reactive- Dispersive transport numerical model was implemented, and its results highlighted that the reductive dechlorination is inhibited by the inorganic Terminal Electron Accepting Processes, enriching groundwater in highly toxic by-products of the reductive dechlorination (i.e. Vinyl Chloride). As a matter of fact, the bacteria using inorganic Terminal Electron Acceptors to oxidize the organic substrate are more efficient than the halo-respiring bacteria, that favor reductive dechlorination. The contaminated site of Bussi Officine case study allowed to clarify the hydrodynamic effect on the redox processes and the anoxic condition distribution. The comparison between dissolved chlorinated solvents and the inorganic Terminal Electron Acceptors distribution in the aquifer pointed out that dispersion inhibits all the redox processes because it dilutes the organic substrate concentration in groundwater. On the other hand, the lacustrine deposits rich organic matter (i.e. peat) can be considered as “chemical reactors”, that releases by back-diffusion toxic by-product of the reductive dichlorination in groundwater.

Sustainable vanadium(V)-catalyzed oxybromination of styrene: Two-phase system versus ionic liquids

2005 ◽  
Vol 77 (9) ◽  
pp. 1575-1581 ◽  
Author(s):  
Valeria Conte ◽  
Barbara Floris ◽  
Pierluca Galloni ◽  
Adriano Silvagni
Keyword(s):  
Ionic Liquids ◽  
Aqueous Phase ◽  
Chlorinated Solvents ◽  
Reaction Rates ◽  
Point Of View ◽  
Metal Catalyst ◽  
Phase System ◽  
Two Phase ◽  
System Versus ◽  
Bromide Ion

Oxybromination reaction of styrene was performed in a two-phase system of water/ionic liquids (ILs). The aim of the work was to make the mild and efficient two-phase system previously developed for the vanadium(V)-catalyzed oxybromination of alkenes, inspired by the activity of haloperoxidase enzymes, even more interesting from a sustainable point of view. As in that case, a brominating intermediate was formed from the metal catalyst, H2O2, and bromide ion in the acid aqueous phase, but chlorinated solvents were replaced with ILs.[bmim+][PF6-], [bm2im+][PF6-], [bmim+][BF4-], [bmim+][CF3SO3-], and [bmim+][(CF3SO2)2N-] were tested. We report on interesting results in terms of reaction rates and selectivities.

Dynamic Technique to Determine Hexadecane Transfer Rate from Organic Phase to Aqueous Phase in a Three-Phase Bioreactor

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Manuel Alejandro Lizardi-Jiménez ◽  
Gerardo Saucedo-Castañeda ◽  
Frederic Thalasso ◽  
Mariano Gutiérrez-Rojas
Keyword(s):  
Mass Transfer ◽  
Aqueous Phase ◽  
Transfer Rate ◽  
Water Soluble ◽  
Airlift Bioreactor ◽  
Dynamic Technique ◽  
Three Phase ◽  
Consortium Culture

Determination of mass transfer of non-water soluble substrates, as hexadecane (HXD), is an important constraint in three-phase airlift bioreactor. A new simple dynamic technique able to measure the hexadecane transfer rate (HTR) in a three-phase airlift bioreactor (ALB) was studied in this work. The image analyses technique allowed measuring the resulting specific mass transfer area (aHXD). Gas chromatography was used to measure time-dependent transferred HXD and therefore the HXD transfer coefficient (kLHXD). Finally, HTR was calculated by using the equation HTR = kLaHXD•(CHXD* - CHXD) where CHXD* and CHXD are the saturation HXD-aqueous interphase and HXD aqueous phase concentration, respectively. As case study, we successfully applied to the measurement of HTR during a typical ALB microbial consortium culture; values from 0.010 to 0.042 mg HXD (L h)-1 were found. This technique could be used to compare similar simultaneously occurring parameters to assess mass transfer constraints in three-phase systems.

Using Surfer 8® to Interpret Light Non-Aqueous Phase Liquid Monitoring Data: A Case Study

2004 ◽  
Vol 6 (4) ◽  
pp. 316-321 ◽  
Author(s):  
Andrew C. Biesterveld ◽  
R. Wane Schneiter ◽  
Raymond W. Marsh
Keyword(s):  
Aqueous Phase ◽  
Monitoring Data ◽  
Phase Liquid

Migration of viscous non-aqueous phase liquids (NAPLs) in alluvium, Fraser River lowlands, British Columbia

2006 ◽  
Vol 43 (7) ◽  
pp. 694-703 ◽  
Author(s):  
Richard E Jackson ◽  
Varadarajan Dwarakanath ◽  
John E Ewing ◽  
John Avis
Keyword(s):  
British Columbia ◽  
Aqueous Phase ◽  
Coal Tar ◽  
Chlorinated Solvents ◽  
Creeping Flow ◽  
Fraser River ◽  
Manufactured Gas Plants ◽  
A Site ◽  
Gas Plants

Coal tar, creosote, and similar viscous non-aqueous phase liquids (NAPLs) behave in alluvial soils in a manner significantly different from that of less viscous NAPLs, such as gasoline and chlorinated solvents. Their unique behavior is due to the interaction of their physical–chemical parameters: a density often greater than water, a viscosity significantly greater than water, and an interfacial tension that yields a positive initial spreading coefficient at air–water–NAPL interfaces. This results in slow, creeping flow that causes long-term contamination at former manufactured gas plants and wood-preserving sites and of their adjacent surface waters. Multiphase simulations of this creeping flow are shown for a site along the lower Fraser River near Vancouver, British Columbia, and the long-term consequences of the migration of viscous NAPLs in alluvium are discussed from the perspective of site characterization and brownfields redevelopment.Key words: creosote, coal tar, multiphase simulation, brownfields, NAPL.

A Fully Operational Pilot Plant for Eliminating Radioactive Oils Mixed With Chlorinated Solvents

2011 ◽  
Author(s):  
A. Jacobs ◽  
W. Everett
Keyword(s):  
Heavy Metals ◽  
Carbon Dioxide ◽  
Aqueous Phase ◽  
Pilot Plant ◽  
Organic Waste ◽  
Chlorinated Solvents ◽  
Lubricating Oil ◽  
Inorganic Salts ◽  
Radioactive Elements ◽  
Lubricating Oils

Disposal of organic liquid waste has become an increasing issue for many nuclear sites. Existing disposal solutions such as incineration or super critical water techniques are not compatible with wastes containing chlorinated solvents or fluorine owing to corrosion problems. As an example several hundred cubic meters of lubricating oils mixed with trichloroethylene (TCE) or perchloroethylene (PCE) are stockpiled on several French nuclear sites. For several years Dewdrops has been developing an original combination of mineralization processes for waste oils and solvents particularly well suited to the nuclear field. The patented technology relies on the alternation of chemical and biological oxidation mechanisms. The oxidized organic material predominately forms carbon dioxide, water and inorganic salts. This paper details the procedure and the results obtained for a particular case at the Tricastin nuclear site of Areva NC (South France). The organic waste used in this study was a 85/15 v/v ratio mix of lubricating oil and TCE. The pilot plant build upon the technology has a daily treatment capacity of approximately 10 liters. In the first step the TCE is mineralized by the photo Fenton reaction. Using hydrogen peroxide with an ultraviolet regenerated iron catalyst, TCE is transformed to carbon dioxide, water and hydrochloric acid. After neutralizing with caustic soda, the next step is a multi-stage biodegradation process to eliminate the remaining lubricating oil. Carefully selected microorganisms use the organic waste as an energy source for their metabolism. During oil biodegradation over 75% of the carbon is released as carbon dioxide while the remaining is incorporated into the biomass. The aqueous phase is continuously separated from the biomass using cross flow filters. The output aqueous phase is treated with ozone and ultraviolet light to eliminate the remaining organic compounds. The final effluent obtained is in conformance with European water standards and can be disposed by normal means. It can also be adjusted to local requirements. The radioactive elements and heavy metals present in these lubricating oils are trapped by the biomass. The excess of biomass is recovered by centrifugation and mineralized by catalytic ozonation technology. The result of the tests was a radioactive waste reduction factor of 15. The mineral residue is a concentrate of inorganic salts with traces of radioactive elements as well as heavy metals. The radioactive elements thus recovered can be consigned to an official repository.

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