Using Ternary Diagrams to Characterize Transport and Attenuation of BTX

Abstract

During the past decade or longer, large amounts of data on the concentrations of dissolved aromatic hydrocarbons have been obtained from routine monitoring of leaky underground storage tanks (USTs). Commonly, aromatic hydrocarbon concentration data is interpreted only within the context of regulatory maximum allowable concentration levels. We show in this paper how ternary diagrams can clearly characterize the physical and chemical controls governing the fate and transport of aromatic hydrocarbons in ground water from routine monitoring data. The results of type mathematical modeling experiments for BTX solute transport show that changes in BTX concentrations, when plotted as proportions on ternary diagrams, form clear “trajectories” documenting major attenuation or transport processes. For example, BTX concentrations affected by biodegradation form a trajectory from the source BTX location on the ternary diagram to the benzene apex. In contrast, BTX concentrations affected by volatilization form a trajectory trending from the source to the xylene apex. Ternary diagrams are easy and effective tools to determine from routine monitoring data (1) whether proposed natural attentuation processes are in fact present, and (2) the efficiency of different remediation efforts used to clean up UST sites.

Status and understanding of groundwater quality in the northern Sierra Nevada foothills domestic-supply aquifer study units, 2015–17—California GAMA Priority Basin Project

“…Toluene is an aromatic hydrocarbon that is commonly found in fuels and solvents and can form as a degradation byproduct of benzene under oxic conditions. Toluene can biodegrade under oxic and anoxic conditions (Lipson and Siegel, 2000). Toluene was only detected in one grid well in each of the two study units, one of which was at moderate RC in the YBW study unit (fig.…”

Assessing Temporal and Spatial Variations of Gasoline-Impacted Groundwater Using Relative Mole Fractions and PIANO Fingerprinting

“…Despite the loss of some specificity, chemical fingerprinting of truly dissolved gasoline-derived constituents in groundwater can still reveal different sources of gasoline (e.g., Yang et al, 1995;Lipson and Siegel, 2000). The use of: 1) effective solubility theory to calculate relative mole fractions in a hypothetical NAPL, or "NAPL-GW fingerprints" (Burris et al, 2006), and 2) solubility-based fingerprinting (Sauer and Costa, 2003), made possible by the use of detailed paraffin, isoparaffin, aromatic, naphthene, and olefin (PIANO) fingerprinting techniques (Uhler et al, 2003), have proven successful in this regard.…”

Application of Diagnostic Tools to Evaluate Remediation Performance at Petroleum Hydrocarbon‐Impacted Sites

“…The Tier 1 level consists of reviewing and interpreting the data already available. While concentration time series provide important background information, additional insight can often be gained through time series of proportions among contaminants, for example, toluene to benzene ratios (Wilson et al ), ternary diagrams for BTX (Lipson and Siegel ), or ratios among all BTEX compounds through tetrahedral analysis (Sra et al ). While dilution changes the concentration of different compounds proportionally, removal processes favor some compounds over others due to differences in physico‐chemical properties or degradability.…”