Advances in the Analysis and Remediation of Hydrocarbons in Soil and Sediment
Abstract: This work documents four studies aimed at advancing site remediation
technology for soils and sediments contaminated with hydrocarbon mixtures, i.e. crude oil,
coal tar. Generally, site remediation follows a three-step process: 1) risk/toxicity
assessment of pollutants, 2) feasibility studies, and 3) full-scale remediation and
long-term monitoring. Because of the wide variety of site... read more-specific characteristics, new
approaches are necessary to improve both analytical accuracy in complex samples and
remediation efficiency for difficult hydrocarbon mixtures, such as heavy oils. The first
two studies document improvements to the routine analysis of alkylated polycyclic aromatic
hydrocarbons (PAH) and sulfur heterocycles (PASH) in complex mixtures by gas
chromatography/mass spectrometry-selected ion monitoring. New analytical methods are
proffered based on the spectral deconvolution of multiple fragmentation patterns of 3-5
ions per alkylated homologue and one pattern per parent compound (MFPPH). These methods
drastically improve quantitative accuracy versus routine analytical methods (e.g.,
standardized methods and industry standardized operating procedures) which monitor only 1
or 2 ions per compound and suffer from matrix interferences. In every case studied, 1- and
2-ion methods resulted in positive bias, often overestimating concentrations by more than
100%. The second half documents a new biosurfactant-enhanced polymer partitioning system
for the fast, efficient remediation of heavy hydrocarbon (e.g., coal tar or heavy crude
oil) contaminated soils and sediments. A renewable crop-based biosurfactant, CT1, mobilizes
organics from the solid matrix, assisting hydrocarbon adsorption onto polystyrene foam due
to favorable hydrocarbon-sorbent surface interactions. Between 80% and 94% removal was
obtained after only ½ to 2 hours of mixing, despite using only a fraction of the sorbent
mass and mobilizing phase volume as previous reactors. This technology was field-tested and
found cost-competitive with the current industry standard technology of dig-and-haul.
Importantly, if recycled polystyrene foam is used, and since CT1 is produced from renewable
feedstock, this technology is considered a "green" chemistry solution.
Thesis (Ph.D.)--Tufts University, 2016.
Submitted to the Dept. of Chemistry.
Advisor: Albert Robbat Jr.
Committee: Swapan Jain, Samuel Thomas, and Samuel Kounaves.
Keywords: Analytical chemistry, Environmental engineering, and Environmental health.read less