EFFECTS OF XAD-8 FRACTIONS OF DISSOLVED ORGANIC-CARBON ON THE SORPTION AND BIOAVAILABILITY OF ORGANIC MICROPOLLUTANTS
EFFECTS OF XAD-8 FRACTIONS OF DISSOLVED ORGANIC-CARBON ON THE SORPTION AND BIOAVAILABILITY OF ORGANIC MICROPOLLUTANTS
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DOI：
10.1007/bf01059074
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发表时间：
1990-07-01
影响因子：
4
通讯作者：
OIKARI, A
中科院分区：
文献类型：
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作者：
KUKKONEN, J;MCCARTHY, JF;OIKARI, A
通过XAD-8层析，将泥炭沉积附近溪水中溶解的有机碳(DOC)分成疏水酸(HBA)、疏水中性(HBN)和亲水(Hl)三个亚组分。用平衡透析法测定了这些组分和总(未分馏)水对疏水性有机污染物的结合能力，并测定了结合对大型水蚤体内污染物生物利用度的影响。模型污染物为多环芳烃、萘(NPH)和苯并(A)芘(BaP)，以及多氯联苯、2，2‘’，5，5‘-四氯联苯(TCB)。BaP和TCB都表现出很高的分配系数(Kp‘’S)，既能与总DOC结合，又能与DOC中的疏水成分结合。BaP与HbA组分的亲和力较高，而TCB(和其他3种多氯联苯)与hBN组分的亲和力较高。与H1组分结合的Kp‘’S比与疏水组分结合的Kp‘’值低两到十倍。疏水性较弱的化合物NPH具有较低的Kp，且各组分之间的差异不大。总含水率和不同DOC组分降低了大型沼虾对BaP和TCB的吸收和积累，与DOC结合污染物的能力成正比。数据符合这样的假设，即与DOC(总水或任何部分)结合的污染物不能被生物群吸收。DOC对NPH的吸收没有显著影响，这与其较低的Kp相一致。
The dissolved organic carbon (DOC) from a stream water near a peat deposit was fractionated into hydrophobic-acid (HbA), hydrophobic-neutral (HbN), and hydrophilic (Hl) subcomponents by XAD-8 chromatography. The capacity of these fractions and the total (unfractionated) water to bind hydrophobic organic contaminants was measured by equilibrium dialysis, and the effect of binding on cntaminant bioavailability was measured in Daphnia magna. Model contaminants were the polycyclic aromatic hydrocarbons, naphthalene (NPH) and benzo(a)pyrene (BaP), and the polyclorinated biphenyl, 2,2'',5,5''-tetrachlorobiphenyl (TCB). Both BaP and TCB exhibited high partition coefficients (Kp''s) for binding to both the total DOC and the hydrophobic components of the DOC. BaP had a higher affinity for binding to the HbA fraction, while TCB (and 3 other PCB''s had a higher affinity for the HbN fraction. The Kp''s for binding to the Hl fraction were twofold to tenfold lower than for binding to the hydrophobic fractions. The less hydrophobic compound, NPH, had a much lower Kp, and little difference was seen between the fractions. The total water and the different DOC fractions reduced the uptake and accumulation of BaP and TCB by D. magna in proportion to the capacity of the DOC for binding the contaminants. Data were consistent with the hypothesis that a contaminant bound to DOC (total water or any of the fractions) is unavailable for uptake by biota. Uptake of NPH was not substantially affected by the DOC, consistent with its lower Kp.