Bench Scale Treatability Laboratory
In-house Applied Research & Laboratory Services
GRT maintains its own in-house applied research and laboratory services unit that performs bench-scale treatability studies on undisturbed soil cores and groundwater. GRT’s bench-scale laboratory has developed innovative remedial technologies and application methods for a broad range of environmental sites. Laboratory studies have led to the full-scale implementation of various technologies.
- Bench-Scale Testing
- Treatability Studies
- Petroleum
- Natural Attenuation
- Biostimulation
- Bioaugmentation
- In Situ/Ex Situ Bioremediation
- Chemical Oxidation
- Metals
- Geochemical Modeling
- Natural Attenuation
- Chemical Barriers
- Ion Exchange Resins
- Chlorinated Solvents
- Natural Attenuation
- Enhanced Anaerobic Bioremediation
- Cometabolic Bioremediation
- Surfactants
- Large & Small Scale Microbial Growth
- Fecal Pollution DNA Test
- Microbial Enumeration
- Microbial Consulting
Petroleum
A patented Pressurized Fluidized Bed Reactor (PFBR) for treatment of VOC contaminated groundwater: unit houses a microbial shearing system that separates attached growth bacteria from the fluidized media. The sheared bacteria are then used for continuous re-injection and the bioaugmentation of the aquifer. GRT completed full-scale design and implementation of the PFBR at a State of Michigan Department of Transportation site associated with a large Superfund project in Clare, Michigan. The reactor was key to bringing the site to a residential closure.
Isolation of indigenous diesel-degrading microorganisms: GRT’s laboratory work led to the full-scale development of a dieseldegrading batch bioreactor, which was designed and installed at a Michigan Department of Transportation remediation project. This bioaugmentation system produced inocula for both land application treatment of soil piles and in situ groundwater treatment, cleaning up and closing the site ahead of schedule and under budget.
In situ ozone-enhanced air sparge system treatment for 1,2,4-trimethylbenzene coupled with density driven convection wells, bench-scale treatability study, pilotscale testing, full-scale design and installation: the bench-scale testing led to an understanding of proper ozone production quantities for the full-scale system that would successfully eliminate the discharge of trimethylbenzenes to a northern Michigan lake.
Use of surfactants to mobilize pyrolitic oil: GRT conducted a bench-scale treatability test on the feasibility of removing pyrolitic oil from the capillary fringe of an unconfined aquifer using biodegradable surfactants. The study resulted in a greater understanding of surfactant heating, concentration and delivery methods.
Vacuum-enhanced free-product removal: GRT bench tested methods for free product removal based on the specific gravity difference between groundwater and LNAPL product. After bench testing, GRT installed a low cost, full-scale free product recovery system that successfully removed product from up to 14 wells simultaneously at a former refinery site.
Global Remediation Technologies, Inc. (GRT)
performed a bench study to determine if the
organic fraction of PNA, BTEX and heavy metal
contaminated soil could be efficiently degraded by
solid-phase bioremediation or land farming.
Ex situ Bioremediation Potential Bench Study
Initial contaminant concentrations:
- 2,000 mg/kg total BTEX with 1,000 mg/kg as benzene
- 1,000 mg/kg total PAHs
- 40 mg/kg Arsenic
- 100 mg/kg Chromium
- 300 mg/kg Lead
Experimental Set up
Bioremediation chambers were filled with site soil and various amendments were added based on the treatment regimen. Treatment regimens included tilling and irrigation (all treatments), nutrients, commercially available microbes known to be tolerant to heavy metals (client’s request), and SVE.
Summary
- All BTEX components were below clean-up criteria with the exception of benzene after 56 days.
- PNA concentrations were below or near clean-up criteria after 56 days.
- The combination of nutrient, microbes, and SVE was the most effective treatment.
Metals
In situ treatment of dissolved nickel by chemically binding it to the aquifer soil: preliminary results using laboratoryintroduced nickel appeared promising and confirmed predictions from GRT’s geochemical modeling (MINTEQ). However, when site groundwater was used in the experiment, the nickel would not bind to the soil in the column. After additional investigation, we discovered that the chelating agent EDTA was also present in the dissolved nickel plume, keeping the nickel in solution. Consequently, an alternative treatment method was sought. This study underscores the value of treatability testing.
Global Remediation Technologies, Inc. (GRT) used
geochemical modeling and bench scale testing to examine
treatment alternatives for a groundwater nickel plume.
Geochemical Modeling
GRT applied MINTEQ-A2 to perform aqueous
geochemical calculations to determine the
speciation and proportion of dissolved and
absorbed metal present in groundwater
plumes. The figures below illustrate MINTEQA2
modeling performed on a site with nickel:
- Determined that over 99% of the nickel is
present as dissolved nickel
- Assessed the potential of injecting ferric
chloride to increase binding sites
- Using MINTEQ, determined that over 97%
of the nickel would be sorbed with the
addition of 1 mg/L HFO
Bench Study
A bench study was performed with the goal to monitor adsorption of the dissolved nickel to the aquifer material with and without the presence of hydrous ferric oxides (HFOs).
Experimental Set up
- Used both site water contaminated with
nickel and lab grade nickel solutions
- Ferric chloride was added to soil columns to
induce the formation of HFOs
- Laboratory derived nickel that was
introduced became bound to the newly
created HFOs as modeled
- None of the nickel originating from site water
became bound to the newly created HFOs
- It was later determined that the nickel was
bound to EDTA (a chelating agent)
- Study demonstrated the utility of bench scale
testing prior to field staff consultation
Global Remediation Technologies, Inc. (GRT)
performed a bench study to determine if the
organic fraction of PNA, BTEX and heavy metal
contaminated soil could be efficiently degraded by
solid-phase bioremediation or land farming.
Ex situ Bioremediation Potential Bench Study
Initial contaminant concentrations:
- 2,000 mg/kg total BTEX with 1,000 mg/kg as benzene
- 1,000 mg/kg total PAHs
- 40 mg/kg Arsenic
- 100 mg/kg Chromium
- 300 mg/kg Lead
Experimental Set up
Bioremediation chambers were filled with site soil and various amendments were added based on the treatment regimen. Treatment regimens included tilling and irrigation (all treatments), nutrients, commercially available microbes known to be tolerant to heavy metals (client’s request), and SVE.
Summary
- All BTEX components were below clean-up criteria with the exception of benzene after 56 days.
- PNA concentrations were below or near clean-up criteria after 56 days.
- The combination of nutrient, microbes, and SVE was the most effective treatment.
Chlorinated Solvents
Ex situ co-metabolic TCE bioremediation treatability study: GRT staff tested a process for sequentially producing phenol-monooxygenase enzymes, which fortuitously degrade TCE to carbon dioxide and water. The results of the bench-scale testing led to full-scale implementation of a dual-stage bioreactor that co-metabolically treated TCE for a Michigan Department of Transportation remediation project.
PCE and TCE treatment with potassium permanganate: GRT’s laboratory performed potassium permanganate treatability tests on PCE and TCE contaminated soils. The soil oxidant demand was measured to determine a suitable permanganate dosage.
Source Determination of Fecal Pollution
Global Remediation Technologies, Inc (GRT) specializes in DNA tests.
Case Study
A village in northern Michigan participated in E. Coli beach monitoring events in 2002; on more than one occasion, E. coli counts exceeded the acceptable recreation contact level during the summer sampling events.
Samples (replicates of three) were collected from a beach located in the village once a week during the months of July and August.
GRT used a culture independent method to determine if the source of fecal contamination in water is of human origin or not; a genetic marker was used from the Bacteroides-Prevotella group.
GRT used the polymerase chain reaction (PCR) to amplify a portion of a bacterial gene that are only found in humans.
DNA testing samples were scored positive (+) or negative (-) for human fecal pollution.
The Village Council and its citizens used the data obtained as they discussed options for a centralized wastewater treatment system.
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