Janfada Arash, Headley John V, Peru Kerry M, Barbour S L
Department of Civil Geological Engineering, University of Saskatchewan, Canada.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2006;41(6):985-97. doi: 10.1080/10934520600620105.
The adsorption characteristics of oil sands tailings pond water (OSTPW)-derived naphthenic acids on soils was determined using a batch partitioning method. The adsorption isotherms were found to be linear in all cases. All tests were conducted at 4 degrees C, and at a pH of 8.0 +/- 0.4, which reflects the pH of a tailings settling facility near Fort McMurray, AB. The adsorption characteristics of the naphthenic acids in a synthetic groundwater (SGW) solution was compared to that of the mixture in Milli-Q water. In the presence of SGW, the adsorption coefficient (K(d)) of the mixture of naphthenic acids on soil 1 with a higher organic carbon fraction (f(oc)) was an order of magnitude higher than that observed with the same soil and the Milli-Q water mixture, increasing from 1.9 +/- 0.2 (mL/g) to 17.8 +/- 1.5 (mL/g). The adsorption coefficient of the mixture of naphthenic acids on soil 2, with a lower f(oc), was also observably higher in the SGW mixture, increasing from 1.3 +/- 0.15 (mL/g) to 3.7 +/- 0.2 (mL/g). The relative fractional abundance of the individual naphthenic acids was plotted in order to determine the presence of preferential sorption between individual species within the mixture. It was found that for all Z families (where Z is a measure of the number of rings), naphthenic acids within the carbon number range of 13 to 17 showed preferential sorption. The mixture in SGW showed more pronounced sorption relative to naphthenic acid mixture in Milli-Q water. The results indicate that mixtures of naphthenic acids sorb strongly to soils and that adsorption would be an important attenuating mechanism in groundwater transport. Furthermore, preferential sorption of the individual naphthenic acids is important from a toxicity stand point since different naphthenic acid species have varying degrees of toxicity.
采用批量分配法测定了油砂尾矿池水（OSTPW）衍生环烷酸在土壤上的吸附特性。发现所有情况下吸附等温线均为线性。所有试验均在4℃、pH值为8.0±0.4的条件下进行，该pH值反映了艾伯塔省麦克默里堡附近尾矿沉降设施的pH值。将合成地下水（SGW）溶液中环烷酸的吸附特性与超纯水混合液中环烷酸的吸附特性进行了比较。在SGW存在的情况下，环烷酸混合物在有机碳含量分数（f(oc)）较高的土壤1上的吸附系数（K(d)）比在相同土壤和超纯水混合液中观察到的吸附系数高一个数量级，从1.9±0.2（mL/g）增加到17.8±1.5（mL/g）。环烷酸混合物在f(oc)较低的土壤2上的吸附系数在SGW混合液中也明显更高，从1.3±0.15（mL/g）增加到3.7±0.2（mL/g）。绘制了各环烷酸的相对分数丰度，以确定混合物中各物种之间是否存在优先吸附。结果发现，对于所有Z族（其中Z是环数的度量），碳数范围在13至17之间的环烷酸表现出优先吸附。相对于超纯水中的环烷酸混合物，SGW中的混合物表现出更明显的吸附。结果表明，环烷酸混合物对土壤有强烈的吸附作用，吸附将是地下水运移中的一种重要衰减机制。此外，从毒性角度来看，各环烷酸的优先吸附很重要，因为不同的环烷酸物种具有不同程度的毒性。
