A plethora of interesting research items from US EPA TINS:
(Note TINS archives are at https://clu-in.org/plweb-cgi/fastweb.exe ...
RAPID ASSESSMENT OF REMEDIAL EFFECTIVENESS AND REBOUND IN FRACTURED BEDROCK
Schaefer, C., D. Lippincott, K. Hatfield, and H. Klammler.
ESTCP Project ER-201330, 126 pp, 2017
A rapid assessment (RA) protocol was developed in this project to assess the potential effectiveness of in situ treatment by chemical oxidation or bioaugmentation.
The RA protocol is intended to assess chlorinated ethene rebound, the potential of naturally occurring dechlorination reactions in low permeability zones,
and remedial effectiveness using a pair of closely spaced bedrock wells. The RA technique involves identifying hydraulically conductive fracture zones,
flushing contaminant from the fracture zones using water, and then evaluating contaminant rebound within this zone while hydraulically isolating the zone
from the surrounding contaminated aquifer. The rate, composition, and isotopic signature of contaminant rebound is then used to evaluate the limits of remedial
effectiveness, identify the local source/cause of any observed rebound, and improve the site conceptual model. Work was performed at the former Naval Air
Warfare Center (NAWC) in Trenton, New Jersey, as a preliminary test site to develop the methodology. The former Naval Construction Battalion Center (NCBC)
Davisville (Calf Pasture Point) in North Kingston, Rhode Island, was used for more quantitative purposes and evaluation of the RA testing protocol during
rapid flushing of a TCE-contaminated zone using water spiked with bromide tracer. Results from the second site are the focus of this report. https://www.serdp-estcp.org/content/down ...
PHYTOSCREENING FOR VINYL CHLORIDE IN GROUNDWATER DISCHARGING TO A STREAM
Ottosen, C.B., V. Ronde, S. Trapp, P.L. Bjerg, and M.M. Broholm.
Groundwater Monitoring & Remediation 38(1):66-74(2018)
An optimized phytoscreening method was used to locate a chlorinated ethene plume discharging into a stream. Trees along the stream bank were monitored through
different seasons under different environmental conditions to evaluate seasonal uptake/loss scenarios. Detection of VC, cis-DCE, TCE, and PCE in the trees
showed that phytoscreening is a viable method to locate chlorinated ethene plumes, including VC, discharging to streams. Phytoscreening for VC was found
to be more sensitive to environmental conditions affecting transpiration than the other chlorinated ethenes detected. This paper is temporarily Free Access
at http://onlinelibrary.wiley.com/doi/10.11 ...
THE HORIZONTAL REACTIVE MEDIA TREATMENT WELL (HRX WELL®) FOR PASSIVE IN-SITU REMEDIATION
Divine, C.E., T. Roth, M. Crimi, A.C. DiMarco, M. Spurlin, J. Gillow, and G. Leone.
Groundwater Monitoring & Remediation 38(1):56-65(2018)
A new in situ remediation concept—the Horizontal Reactive Media Treatment Well (HRX Well®)—utilizes horizontal wells filled with reactive media (e.g.,
zero-valent iron, activated carbon, ion exchange resins, zeolite, apatite, chitin) for passive in situ treatment of contaminated groundwater. The horizontal
wells generally are installed parallel to the direction of groundwater flow to leverage natural flow-focusing behavior induced by the high in-well hydraulic
conductivity of the reactive media relative to the aquifer hydraulic conductivity. 3D flow and transport simulations showed that capture and treatment widths
of up to tens of feet can be achieved for many aquifer settings, and reductions in downgradient concentrations and contaminant mass flux are nearly immediate.
This paper is temporarily Free Access at http://onlinelibrary.wiley.com/doi/10.11 ... The HRX Well technology is currently in the process
of demonstration and field validation under ESTCP project ER-201631: https://www.serdp-estcp.org/Program-Area ...
THE IMPACT OF WELL-FIELD CONFIGURATION AND PERMEABILITY HETEROGENEITY ON CONTAMINANT MASS REMOVAL AND PLUME PERSISTENCE
Guo, Z. and M.L. Brusseau.
Journal of Hazardous Materials 333:109-115(2017)
The impact of different well-field configurations on pump-and-treat mass removal in a heterogeneous subsurface was simulated in a 3D numerical model with
the metric to examine remediation efficiency provided by the relationship between reduction in contaminant mass discharge (CMDR) and mass removal (MR).
Systems whose CDMR-MR profiles were below the 1:1 relationship line were associated with more efficient well-field configurations. The impact of domain
heterogeneity on mass-removal effectiveness was investigated in terms of both variance and correlation scale of the random permeability distributions
and indexed by the CMDR-MR relationship. Pump-and-treat data from the Tucson International Airport Area federal Superfund site were obtained for comparison
between simulated and measured site data. Results from the field data case study are consistent with the conclusions of the theoretical study, which supports
the general validity of the numerical model. See additional information on this study in Appendix B of Z. Guo's dissertation at http://arizona.openrepository.com/arizon ...
VAPOR INTRUSION RISK OF FUEL ETHER OXYGENATES METHYL TERT-BUTYL ETHER (MTBE), TERT-AMYL METHYL ETHER (TAME) AND ETHYL TERT-BUTYL ETHER (ETBE): A MODELING
Ma, J., D. Xiong, H. Li, Y. Ding, X. Xia, and Y. Yang.
Journal of Hazardous Materials 332:10-18(2017)
A modeling study conducted to investigate the vapor intrusion potential of MTBE, TAME, and ETBE indicated that MTBE is much more likely to cause vapor intrusion
problems than TAME and ETBE. The authors' findings led them to recommend that EPA consider including the field measurement data of synthetic fuel additives
in the existing Petroleum Vapor Intrusion Database.
DETERMINING GROUNDWATER MTBE SOURCES USING REVERSE PARTICLE TRACKING: TWO CASE STUDIES
Mohsen, F. and R. O'Boyle.
Environmental Forensics 18(4):272-284(2017)
In two case studies, low levels of MTBE were alleged to have entered residential wells from neighboring gas stations. Reverse particle tracking in the first
case established that only 8 of 32 plaintiffs' residential wells could have been affected by MTBE migrating from the gas station. In the second case, reverse
particle tracking identified a source farther upgradient from a suspected gas station source that explained the occurrence of MTBE contamination in a nursery
as well as in residential wells downgradient of the gas station.
TETRACHLOROETHENE RELEASE AND DEGRADATION DURING COMBINED ERH AND SODIUM PERSULFATE OXIDATION
Costanza, J., T. Marcet, N.L. Capiro, and K.D. Pennell.
Groundwater Monitoring & Remediation 37(4):43-50(2017)
A study was conducted to determine the extent of PCE degradation during bench-scale thermal treatment of a PCE-contaminated silty clay loam using electrical
resistance heating (ERH). The soil was collected from a contaminated area at a former dry cleaning facility. After 30 days of ERH, 52% of the initial PCE mass
was recovered, potentially indicating that 48% of the PCE was degraded during ERH. The potential benefit of adding heat-activated sodium persulfate during
treatment was evaluated in a second experiment. After 19 days of ERH and three persulfate injections, 93% of the initial PCE was recovered, with 3% PCE destruction
based on chloride evolution. The difference in mass recovery between the first and second experiments might have been due to differences in the initial mass
of PCE, even though both experiments used soil from the same core. Results suggest that most of the mass recovered during ERH of the PCE-contaminated soil at
the former dry cleaning facility can be attributed to volatilization and gas phase extraction rather than abiotic degradation.
EFFECTS OF VARIABLE SITE CONDITIONS ON PHYTOREMEDIATION OF MIXED CONTAMINANTS: FIELD-SCALE INVESTIGATION AT BIG MARSH SITE
Reddy, K.R. and G. Amaya-Santos.
Journal of Environmental Engineering 143(9):(2017)
Big Marsh is a large wetland site contaminated with PAHs and heavy metals following decades of illegal waste dumping. Three different experimental areas,
representative of three site ecotypes, were selected for a field-scale phytoremediation project. Nine native and restoration species were planted at each
area and assessed over three growing seasons for their potential to survive and remediate the soil. Each area was tilled prior to planting, and compost was added
to one of the areas. At the end of the third season, analysis of PAH and heavy metal concentrations in roots and shoots of the surviving species and in the soil samples
collected in each growing season showed a decrease in PAH concentrations in the compost-amended area. In the unamended areas, PAHs uptake occurred only in
the roots of the surviving species. Despite root uptake of metals by all the surviving species, no substantial changes were found in soil metal concentrations
in the planted experimental areas.
A REVIEW OF CONTAMINATION OF SURFACE-, GROUND-, AND DRINKING WATER IN SWEDEN BY PERFLUOROALKYL AND POLYFLUOROALKYL SUBSTANCES (PFASs)
Banzhaf, S., M. Filipovic, J. Lewis, C.J. Sparrenbom, and R. Barthel.
This review describes potential sources for PFASs to enter the drinking water supply in Sweden and compares different occurrences of PFASs in raw and drinking
water in that country. Monitoring history, the legal situation, and remedial actions taken are also discussed. https://www.ncbi.nlm.nih.gov/pmc/article ...
MASS FLOW AND FATE OF PER- AND POLYFLUOROALKYL SUBSTANCES IN A LANDFILL IN UPPSALA, SWEDEN
Bonnet, Bjoern Frederik, Master's thesis, Swedish University of Agricultural Sciences, Upsala. 68 pp, 2017
In a study of PFAS translocation from a landfill via drainage into nearby water systems, distribution and fate of 28 PFASs were analyzed in drainage water,
sewage sludge, and groundwater all across the landfill area and in the receiving water courses. The total mass flow of PFASs exiting the landfill was estimated
at 220 mg/g. The mass flow in the river showed no long-range effect (30 km) of the landfill PFASs on surface waters; instead, PFASs from the landfill appeared
to present a greater threat to the local groundwater. The study included assessment of an on-site drainage water treatment system in terms of PFAS removal efficiency.
The treatment system showed efficiencies of around 50% for the simple treatment techniques applied (i.e., aeration, moving bed biofilm reactor, sedimentation
pond, polishing ponds/lakes, and oxidation pond). https://stud.epsilon.slu.se/13052/
REVIEW OF THE FATE AND TRANSFORMATION OF PER- AND POLYFLUOROALKYL SUBSTANCES (PFASs) IN LANDFILLS
Hamid, H., L.Y. Li, and J.R. Grace.
Environmental Pollution 235:74-84(2018)
Despite its restricted use, PFOA remains one of the most abundant perfluorinated alkyl acids (PFAAs) in landfill leachates. The presence of PFAA precursors
(e.g., saturated and unsaturated fluorotelomer carboxylic acids) also has been documented in landfill leachates at high concentrations. Landfill ambient
air has been found to contain elevated concentrations of PFASs, primarily semi-volatile precursors (e.g., fluorotelomer alcohols), compared to upwind
control sites, which suggests that landfills are potential sources of atmospheric PFASs. PFAS fate inside landfills is controlled by a combination of biological
and abiotic processes, with biodegradation releasing most of the PFASs from landfilled waste to leachate. Determination of PFAA precursors and their degradation
products is recommended for future studies to avoid significant underestimation of total PFAS released from landfills.
PERMEABLE BIOSORBENT BARRIER FOR WASTEWATER REMEDIATION
Silva, B., E. Tuuguu, F. Costa, V. Rocha1, A. Lago, and T. Tavares.
Environmental Processes 4(Suppl 1):195-206(2017)
In a study of Cr(III) removal from surface water by a permeable barrier, the adsorption capacity of 13X zeolite and vermiculite was investigated at different
sorbent dosages, pH, and initial Cr(III) concentration in a lab-scale reactor set up to simulate a permeable barrier. 13X zeolite had the better performance
for Cr removal in the permeable barrier assays, achieving 96% total Cr removal and a global uptake of 2.49 mg/g. Neither barrier had reached Cr saturation after
13 days of operation. Additionally, a fungal isolate identified as belonging to Alternaria alternate was obtained from sediment samples and selected from
enriched Luria-Bertani medium. After 50 h of cellular growth the fungal isolate was able to remove 78.2% and 47.9% of Cr(III) at initial concentrations of 50
mg/L and 100 mg/L, respectively. https://repositorium.sdum.uminho.pt/bits ...