Kitis Mehmet, Karanfil Tanju, Wigton Andrew, Kilduff James E
Department of Environmental Engineering and Science, Clemson University, 342 Computer Court, Anderson, SC 29625, USA.
Water Res. 2002 Sep;36(15):3834-48. doi: 10.1016/s0043-1354(02)00094-5.
The disinfection by-product (DBP) reactivity (yield and speciation upon reaction with chlorine) of dissolved organic matter (DOM) isolated from two surface waters was investigated. The source waters, each having significantly different specific ultraviolet absorbance (SUVA254), molecular weight (MW) distribution and polarity, were fractionated using XAD-8 resin adsorption and ultrafiltration (UF), with good DOM mass balance closures (based on dissolved organic carbon). It was found that such fractionation preserved both the SUVA and the reactivity of the source waters, as demonstrated by statistically similar DBP formation and speciation from chlorinated source water and source waters reconstituted from XAD-8 or UF fractions. In addition, there was no evidence of synergistic effects among DOM components when reacting with chlorine. Consistent trends between DBP yields and MW were not found. Hydrophobic fractions of DOM (isolated by XAD-8) were the most reactive DOM components; however, hydrophilic components also showed appreciable DBP yields, contributing up to 50% of total DBP formation. In contrast, strong and unique correlations were observed between the SUVA of individual fractions and their trihalomethane (THM) and haloacetic acid (HAA9) yields, confirming that the aromaticity of DOM components is more directly related to reactivity than other physicochemical properties. The finding of a single correlation independent of the fractionation process employed is notable because XAD-8 adsorption and UF fractionate DOM by significantly different mechanisms. These results confirm that SUVA is a distributed parameter that reflects DOM heterogeneity. Therefore, the SUVA distribution within natural water represents an important property that can be used as a reliable predictor of DBP formation. Finally, bromine appears to be more effectively incorporated into low UV-absorbing (i.e., low SUVA), low MW and hydrophilic DOM fractions.
研究了从两种地表水中分离出的溶解有机物（DOM）的消毒副产物（DBP）反应活性（与氯反应时的产率和形态）。这两种水源水的特定紫外吸光度（SUVA254）、分子量（MW）分布和极性均有显著差异，采用XAD - 8树脂吸附和超滤（UF）进行分级分离，溶解有机碳的DOM质量平衡封闭良好。结果发现，这种分级分离保留了水源水的SUVA和反应活性，氯化水源水以及由XAD - 8或UF级分重构的水源水的DBP形成和形态在统计学上相似即证明了这一点。此外，没有证据表明DOM各组分与氯反应时存在协同效应。未发现DBP产率与分子量之间存在一致的趋势。DOM的疏水级分（通过XAD - 8分离）是反应活性最高的DOM组分；然而，亲水组分也显示出可观的DBP产率，对总DBP形成的贡献高达50%。相比之下，观察到各个级分的SUVA与其三卤甲烷（THM）和卤乙酸（HAA9）产率之间存在强烈且独特的相关性，证实了DOM组分的芳香性比其他物理化学性质更直接地与反应活性相关。发现一个与所采用的分级分离过程无关的单一相关性值得注意，因为XAD - 8吸附和UF通过显著不同的机制对DOM进行分级分离。这些结果证实SUVA是一个反映DOM异质性的分布参数。因此，天然水中的SUVA分布是一项重要特性，可作为DBP形成的可靠预测指标。最后，溴似乎更有效地掺入低紫外吸收（即低SUVA）、低分子量和亲水的DOM级分中。
