University of Maribor, Faculty of Civil Engineering, Transportation Engineering and Architecture, Smetanova Ulica17, Maribor SI-2000, Slovenia.
Jožef Stefan Institute, Department of Environmental Sciences, Jamova Cesta 39, Ljubljana, Slovenia.
Water Res. 2018 Nov 1;144:254-264. doi: 10.1016/j.watres.2018.07.042. Epub 2018 Jul 17.
Benzotriazoles (BTs) are regarded as contaminants of emerging concern. However, their transformation products (BTTPs) in aquifers remains poorly characterized. The present study is the first detailed report on profiles of the BTTPs in an urban oxic intergranular aquifer related to water type, land use and the aquifer's depth. The 2-methyl-2H-benzotriazole (2-MeBT) and 2,4-dimethyl-2H-benzotriazole (2,4-dMeBT) were quantified using the gas chromatography-mass spectrometry (GC-MS) analytical technique based on internal standards. For the first time the relationship between the 2-MeBT and 2,4-dMeBT concentrations was studied in sampled water and discussed with respect to the different flow paths and sources of contamination. Three main sources of BTTPs were determined in urban groundwater: BTs and BTTPs included in the outflow of effluents from wastewater-treatment plants and energy-producing facilities into surface streams that recharge the aquifer and in the leaking effluents from industrial and public wastewater pipelines. The results confirm that the BTTPs are transformed from parent compounds in the aquifer's unsaturated zone in the case when the effluents are temporally stored in sediments with a lower hydraulic conductivity, which is indicated with the highest median concentrations of BTTPs referring to the perched aquifers where the BTTPs proportions were 92-99%. BTTPs dominated over the parent BTs also in groundwater. The highest concentrations of BTTPs (up to 174 and 144 ng L for the 2-MeBT and 2,4-dMeBT ng L, respectively) were measured in groundwater abstracted from the upper parts of the aquifer in the area where the losses from industrial wastewater pipelines were evidenced. The 2,4-dMeBT dominated over the 2-MeBT in the BTTPs originating from BTs included in the industrial effluents, which is the opposite to the case when their origin is in the municipal effluents. The median sum concentration of the BTTPs in drinking-water resources (2.0 ng L) is lower than the quality criterion recommended for BTs so far. Nevertheless, the abundance of BTs in the environment and the apparent environmental relevance of the BTTPs in urban groundwater indicate the need for a risk assessment of BTTPs with respect to health and the environment.
苯并三唑（BTs）被认为是新兴的关注污染物。然而，它们在含水层中的转化产物（BTTPs）仍然描述不足。本研究首次详细报告了与水类型、土地利用和含水层深度有关的城市好氧颗粒含水层中 BTTPs 的分布情况。采用基于内标物的气相色谱-质谱（GC-MS）分析技术，对 2-甲基-2H-苯并三唑（2-MeBT）和 2,4-二甲基-2H-苯并三唑（2,4-dMeBT）进行了定量分析。首次研究了所采水样中 2-MeBT 和 2,4-dMeBT 浓度之间的关系，并结合不同的水流路径和污染来源进行了讨论。在城市地下水中确定了三个主要的 BTTPs 来源：废水处理厂和能源生产设施的废水流出物以及补给含水层的地表溪流中包含的 BTs 和 BTTPs，以及工业和公共废水管道泄漏的流出物。结果证实，在废水在水力传导率较低的沉积物中临时储存的情况下，BTTPs 是从含水层不饱和带中的母体化合物转化而来的，这一点在 BTTPs 比例最高的高位含水层中得到了证实，最高浓度的 BTTPs 指的是含有 BTTPs 的含水层，比例为 92-99%。BTTPs 在地下水中也超过了母体 BTs。在该地区，工业废水管道泄漏的证据表明，从含水层上部抽取的地下水的 BTTPs 浓度最高（2-MeBT 和 2,4-dMeBT 分别高达 174 和 144ngL）。BTTPs 中来源于工业废水中 BTs 的 2,4-dMeBT 超过了 2-MeBT，而来源于城市废水中 BTs 的情况则相反。饮用水资源中 BTTPs 的中值总和浓度（2.0ngL）低于迄今为止推荐的 BTs 质量标准。然而，BTs 在环境中的丰度以及 BTTPs 在城市地下水中的明显环境相关性表明，需要对 BTTPs 的健康和环境风险进行评估。
