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Groundwater flow near a recirculation well with mixed-type boundary condition along wellbore in confined, unconfined, leaky, or reservoir-covered aquifers.
APTIM Authors/Contributors Tomas Perina, Project Manager, Environmental Services Abstract Vertical recirculation wells used for remediation or heat recovery induce drawdown distribution that varies for confined, unconfined, leaky, and reservoir-covered aquifers. A recirculation well with arbitrary arrangement of extraction and injection screen intervals is simulated with the general well function of…
https://www.aptim.com/media/publications/groundwater-flow-near-a-recirculation-well-with-mixed-type-boundary-condition-along-wellbore-in-confined-unconfined-leaky-or-reservoir-covered-aquifers/Linking water quality to drinking water treatment costs using time series analysis: Examining the effect of a treatment plant upgrade in Ohio
APTIM Authors/Contributors Donald Schupp, Project Manager, Quality Assessment Tasks Abstract We estimate a cost function for a water treatment plant in Ohio to assess the avoided-treatment costs resulting from improved source water quality. Regulations and source water concerns motivated the treatment plant to upgrade its treatment process by adding a…
https://www.aptim.com/media/publications/linking-water-quality-to-drinking-water-treatment-costs-using-time-series-analysis-examining-the-effect-of-a-treatment-plant-upgrade-in-ohio/A field study to assess the role of air-water interfacial sorption on PFAS leaching in an AFFF source area.
APTIM Authors/Contributors Abstract Field-deployed lysimeters were used to measure the concentrations of poly- and perfluoroalkyl substances (PFASs) in soil porewater at a site historically impacted with aqueous film forming foam (AFFF). Samples collected over a 49-day period showed that perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) were the PFASs with…
https://www.aptim.com/media/publications/a-field-study-to-assess-the-role-of-air-water-interfacial-sorption-on-pfas-leaching-in-an-afff-source-area/Semi-analytical model for solute transport in a three-dimensional aquifer with dual porosity and a volumetric source term
APTIM Authors/Contributors Tomas Perina, Project Manager, Environmental Services Abstract A new solution for advective–dispersive solute transport is developed for three-dimensional aquifer of finite thickness and width, infinite extent along the direction of flow, dual porosity, equilibrium linear sorption and first-order decay of both the sorbed and dissolved mass with coefficients…
https://www.aptim.com/media/publications/semi-analytical-model-for-solute-transport-in-a-three-dimensional-aquifer-with-dual-porosity-and-a-volumetric-source-term/Strategic approaches to sediment management for restoration of a deltaic plain
APTIM Authors/Contributors Background/Objectives Sediment resources are essential to fulfill the State of Louisiana’s commitment to implement a Coastal Master Plan (CMP) to mitigate its chronic land loss, protect more than 2 million people who live in the coastal zone, and to save Louisiana’s rapidly disappearing complex and fragile ecosystem. With…
https://www.aptim.com/media/publications/strategic-approaches-to-sediment-management-for-restoration-of-a-deltaic-plain/Abiotic reduction of 3-nitro-1,2,4-triazol-5-one (NTO) and other munitions constituents by wood-derived biochar through its rechargeable electron storage capacity
APTIM Authors/Contributors Mark E. Fuller, Senior Research Scientist, Biotechnology Development and Applications Group (BDAG) Abstract The environmental fate of 3-nitro-1,2,4-triazol-5-one (NTO) and other insensitive munitions constituents (MCs) is of significant concern due to their high water solubility and mobility relative to legacy MCs. Plant-based biochars have been shown to possess…
https://www.aptim.com/media/publications/abiotic-reduction-of-3-nitro-124-triazol-5-one-nto-and-other-munitions-constituents-by-wood-derived-biochar-through-its-rechargeable-electron-storage-capacity/Improved assessment and performance monitoring of a biowall at a chlorinated solvent site using high-resolution passive sampling
APTIM Authors/Contributors Background / Objectives This study contrasts the use of high-resolution passive sampling and traditional groundwater monitoring wells (GWMW) to characterize a chlorinated solvent site and assess the effectiveness of a biowall (mulch, compost and sand) that was installed to remediate trichloroethene (TCE), the primary contaminant of concern. High-resolution…
https://www.aptim.com/media/publications/improved-assessment-and-performance-monitoring-of-a-biowall-at-a-chlorinated-solvent-site-using-high-resolution-passive-sampling/Method for derivatization and isotopic analysis of the insensitive munition compound 3-nitro-1,2,4-triazol-5-one (NTO)
APTIM Authors/Contributors Background/Objectives This paper describes an offline low-temperature derivatization method combined with gas chromatography-isotope ratio mass spectrometry (GC-IRMS) to enable compound-specific isotope analysis (CSIA) of C and N in the explosive compound 3-nitro-1,2,4-triazole-5-one (NTO). NTO is being used widely as a component of insensitive munition (IM) composites such as…
https://www.aptim.com/media/publications/method-for-derivatization-and-isotopic-analysis-of-the-insensitive-munition-compound-3-nitro-124-triazol-5-one-nto/Origin of the isotopic composition of natural perchlorate: Experimental results for the impact of reaction pathway and initial ClOx reactant
APTIM Authors/Contributors Paul Hatzinger, Director of Biotechnology Development and Applications Group Background/Objectives Natural perchlorate (ClO4−) exists in many places on Earth, in lunar regolith, meteorites, and on the surface of Mars. Terrestrial natural ClO4− has widely variable Cl and O stable isotopic compositions (δ37Cl, δ18O, Δ17O). The δ18O and Δ17O values…
https://www.aptim.com/media/publications/origin-of-the-isotopic-composition-of-natural-perchlorate-experimental-results-for-the-impact-of-reaction-pathway-and-initial-clox-reactant/Position-specific isotope effects during alkaline hydrolysis of 2,4-dinitroanisole resolved by compound-specific isotope analysis, 13C NMR, and density-functional theory
APTIM Authors/Contributors Background/Objectives Compound-specific isotope analysis (CSIA), position-specific isotope analysis (PSIA), and computational modeling (e.g., quantum mechanical models; reactive-transport models) are increasingly being used to monitor and predict biotic and abiotic transformations of organic contaminants in the field. However, identifying the isotope effect(s) associated with a specific transformation remains challenging…
https://www.aptim.com/media/publications/position-specific-isotope-effects-during-alkaline-hydrolysis-of-24-dinitroanisole-resolved-by-compound-specific-isotope-analysis-13c-nmr-and-density-functional-theory/