HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Related articles in JEQ Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Hur, J. Articles by Schlautman, M. A. Search for Related Content PubMed PubMed Citation Articles by Hur, J. Articles by Schlautman, M. A. GeoRef GeoRef Citation Agricola Articles by Hur, J. Articles by Schlautman, M. A. Related Collections Humic Substances Other Contaminants Organic Compounds Soil Pollution

TECHNICAL REPORTS

Organic Compounds in the Environment

Effects of Mineral Surfaces on Pyrene Partitioning to Well-Characterized Humic Substances

^a Department of Environmental Engineering & Science and Department of Geological Sciences, School of the Environment, Clemson University, Clemson, SC 29634-0919
^b Institute of Environmental Toxicology, Clemson University, Pendleton, SC 29670

^* Corresponding author (mschlau{at}clemson.edu).

Received for publication July 25, 2003. Mineral surfaces can alter the ability of humic substances (HS) to bind hydrophobic organic contaminants. In this study, complete adsorption (i.e., to avoid HS adsorptive fractionation effects) of a small subset of well-characterized terrestrial and aquatic HS on kaolinite and hematite significantly changed their subsequent organic carbon–normalized partition coefficients for pyrene relative to their original respective dissolved organic carbon–normalized partition coefficients . Parallel experiments with ultrafiltration (UF) fractions obtained from purified Aldrich humic acid (PAHA) (Aldrich Chemical, Milwaukee, WI) gave similar results. The heterogeneity among the PAHA UF fractions was examined via their mineral surface adsorption characteristics and their subsequent ability to bind pyrene. As expected, variations in maximum adsorption densities (q_max), Langmuir adsorption constants (K_q), and pyrene K^ads_oc values were observed among the PAHA UF fractions. However, general trends of q_max, K_q, and pyrene log K^ads_oc values for the PAHA UF fractions versus the logarithm of their weight-average molecular weights (MW_w) did not typically match the corresponding trends obtained with the four aquatic and terrestrial HS. In general, an ideal mixture competitive adsorption model gave reasonable predictions for PAHA sorption to kaolinite and hematite based on their corresponding UF isotherm parameters. Ideal mixture predictions of pyrene partitioning to adsorbed PAHA from the corresponding UF fraction results were better for kaolinite versus hematite, indicating that the underlying mineral surface can alter the effects of HS heterogeneity on hydrophobic organic contaminant sorption.

Abbreviations: DOC, dissolved organic carbon • HOC, hydrophobic organic contaminant • HS, humic substances • MW_w, weight-average molecular weight • PAHA, purified Aldrich humic acid • SHA, soil humic acid • SRFA, Suwannee River fulvic acid • SRHA, Suwannee River humic acid • SUVA, specific ultraviolet absorbance • UF, ultrafiltration

Related articles in JEQ:

This Issue in Journal of Environmental Quality

JEQ 2004 33: 1589-1599. [Full Text]