382-10 Adsorption of BPA, EE2, and 4-NP By Alluvial Soils in Iowa.
See more from this Division: SSSA Division: Soils and Environmental Quality
See more from this Session: Physical, Chemical and Biological Processes Controlling Transport and Remediation of Emerging Contaminants in Soils Oral (includes student competition)
Abstract:
The data were fit by the combined Langmuir-Freundlich model, also referred to as Sip’s isotherm, to generate the adsorption parameters Qmax (adsorption capacity), K (affinity constant), and n (index of heterogeneity). In general, over the wide range of equilibrium concentrations, the model fit was good, with R2 = 0.99. The n values were typically less than 1 or greater than 1, suggesting considerable heterogeneity of the sorption sites, although in BPA-Hanlon system, n=0.96 indicated relatively homogenous sorption sites. Among the three compounds, 4-NP is the least polar and BPA is the most polar. The value of the affinity index, K, for 4-NP was the largest in both the Hanlon and Zook soils, and it was also many times larger than that of in EE2 and BPA. Between the two soils, the Zook soil had much greater adsorption affinity and capacity for EE2 and 4-NP than the Hanlon soil, although with BPA the differences in affinity and capacity were not significant. While organic matter and clay concentration play a big role in adsorption, the chemical properties of the compounds, such as water solubility and octanol-water partition coefficient, are also useful predictors of sorption behavior.
See more from this Division: SSSA Division: Soils and Environmental Quality
See more from this Session: Physical, Chemical and Biological Processes Controlling Transport and Remediation of Emerging Contaminants in Soils Oral (includes student competition)