Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Susan Burns

Second Advisor

Dr. Jay Means

Third Advisor

Dr. John Chateauneuf

Fourth Advisor

Dr. Donald Schreiber

Access Setting

Masters Thesis-Open Access


Partition coefficients (KDOC) for sorption of PAHs and chlorinated benzenes to dissolved humic acids (HA) were measured using gas-sparging methodology. The resulting KDOC values were significantly lower than the KOW-based KDOC values, which generally appear to provide reliable estimates for KDOC values. The KDOC values measured by gas sparging were also strongly influenced by the concentration of HA in solution, as measured by dissolved organic carbon content (DOC). Increasing DOC concentration consistently resulted in decreased KDOC values for all compounds investigated. Previous studies have claimed that KDOC values measured using gas sparging are most accurate at high DOC concentrations, even though the resulting reported KDOC values are significantly lower than Kow-based KDOC values. In the current work, linear regressions of KDOC vs DOC concentration showed that KDOC values measured at lower DOC concentrations better agreed with Kow-based KDOC values. Additionally, this DOC-concentration-dependent phenomena was simulated using the new idea of solute exchange between DOC and gas phases, based on the observations that DOC does accumulate at air-water interfaces.

Included in

Chemistry Commons