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 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 Chow, A. T. Articles by Breuer, R. S. Search for Related Content PubMed PubMed Citation Articles by Chow, A. T. Articles by Breuer, R. S. Agricola Articles by Chow, A. T. Articles by Breuer, R. S. Related Collections Humic Substances Surface Water Quality Water Quality Other Environmental Contamination Water Pollution

TECHNICAL REPORTS

Surface Water Quality

Trihalomethane Reactivity of Water- and Sodium Hydroxide–Extractable Organic Carbon Fractions from Peat Soils

^a Hydrology Program, Department of Land, Air and Water Resources, University of California, Davis, CA 95616
^b Municipal Water Quality Investigations Program Branch, Division of Environmental Services, California Department of Water Resources, P.O. Box 942836, Sacramento, CA 94236-0001
^c USDA-ARS, Water Management Research Unit, Parlier, CA 93648
^d Environmental Water Quality and Estuarine Studies Branch, Division of Environmental Services, California Department of Water Resources, P.O. Box 942836, Sacramento, CA 94236-0001

^* Corresponding author (fguo{at}water.ca.gov)

Received for publication October 25, 2004. Certain organic carbon moieties in drinking source waters of the Sacramento–San Joaquin Delta can react with chlorine during disinfection to form potentially carcinogenic and mutagenic trihalomethanes. The properties of reactive organic carbon in Delta waters, particularly those of soil origin, have been poorly understood. This study attempts to characterize trihalomethane reactivity of soil organic carbon from three representative Delta peat soils. Soil organic carbon was extracted from all three soils with either deionized H₂O or 0.1 M NaOH and sequentially separated into humic acids, fulvic acids, and nonhumic substances for quantitation of trihalomethane formation potential. Water-extractable organic carbon represented only 0.4 to 0.7% of total soil organic carbon, whereas NaOH extracted 38 to 51% of total soil organic carbon. The sizes and specific trihalomethane formation potential (STHMFP) of individual organic carbon fractions differed with extractants. Fulvic acids were the largest fraction in H₂O-extractable organic carbon, whereas humic acids were the largest fraction in NaOH-extractable organic carbon. Among the fractions derived from H₂O-extractable carbon, fulvic acids had the greatest specific ultraviolet absorbance and STHMFP and had the majority of reactive organic carbon. Among the fractions from NaOH-extractable organic carbon, humic acids and fulvic acids had similar STHMFP and, thus, were equally reactive. Humic acids were associated with the majority of trihalomethane reactivity of NaOH-extractable organic carbon. The nonhumic substances were less reactive than either humic acids or fulvic acids regardless of extractants. Specific ultraviolet absorbance was not a good predictor of trihalomethane reactivity of organic carbon fractions separated from the soils.

Abbreviations: DBP, disinfection by-product • STHMFP, specific trihalomethane formation potential • SUVA, specific ultraviolet absorbance • THM, trihalomethane • THMFP, trihalomethane formation potential • TOC, total organic carbon • UVA, ultraviolet absorbance