pH-Dependent Sorption of Chlorinated Guaiacols on Estuarine Sediments: The Effects of Humic Acids and TOC

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• 作者：Jennifer L. Gundersen ; William G. MacIntyre ; and Robert C. Hale
• 刊名：Environmental Science & Technology
• 出版年：1997
• 出版时间：January 1997
• 年：1997
• 卷：31
• 期：1
• 页码：188 - 193
• 全文大小：129K
• 年卷期：v.31,no.1(January 1997)
• ISSN：1520-5851

文摘

Chlorinated guaiacols (o-methoxyphenols) arecomponentsof chlorine-bleached kraft pulp and paper mill effluentsand have been detected in receiving water and sedimentadjacent to paper mills. Their sorption is dependentonboth solvent and sorbent characteristics. Sorption offourchlorinated guaiacols was investigated using fourestuarinesediments from the York River, VA. Sites representedseveraltypes of estuarine environments, ranging from a well-scoured sandy point to a protected tidal mudflat.Totalorganic carbon (TOC) contents ranged from 0.11 to 3.52%(dryweight). NaOH-extractable humic acids ranged from0.03to 1.2% (dry weight). Sorption coefficients,K_d, weremeasured at pH 6.6 and pH 7.8 by the batch isothermmethod.Linear relationships were observed for K_dwith both sedimentTOC and humic acid contents. K_oc andK_humic, sorptioncoefficients normalized to % TOC and % humic acids,respectively, were calculated. Results indicated thatthehumic acid content of a sediment, along with TOC, is animportant factor in controlling the sorption ofchlorinatedguaiacols. Due to differences in hydrophobicity,sorptionof the protonated and deprotonated chlorinated guaiacolspecies is expected to differ. Using accurately measuredpK_a values, the K_d foreach compound was resolved intovalues for the ionized and neutral species (K_d,iand K_d,n,respectively). The results indicated that sorption ofhighlychlorinated, ionized species is appreciable and cannotbe discounted when assessing sorptive reactions.