Aigües de Barcelona - EMGCIA S.A, General Batet 1-7, 08028, Barcelona, Spain.
Aigües de Barcelona - EMGCIA S.A, General Batet 1-7, 08028, Barcelona, Spain.
Water Res. 2019 Jun 1;156:404-413. doi: 10.1016/j.watres.2019.03.026. Epub 2019 Mar 20.
Over the last years, the human probable carcinogen 1,4-dioxane and alkyl-1,3-dioxanes and dioxolanes have been detected and identified as the cause of several pollution episodes in the Llobregat River (Catalonia, NE Spain) and its aquifer. It is an issue of major concern to study these compounds which are released to the environment by resin manufacturing plants' spills and wastewater discharges spread along rivers and reach drinking water treatment plants (DWTPs) in order to protect the environment and public health. In this study four seasonal sampling campaigns were carried out over a year to determine the removal efficiency of the dioxanes and dioxolanes at each step of a DWTP including ozonation, granular activated carbon filters, ultrafiltration and reverse osmosis step's treatments. Additionally, a weekly sampling monitoring of 1,4-dioxane and alkyl-1,3-dioxanes and dioxolanes in raw water, groundwater and finished water was performed at a DWTP over more than two years. Aqueous odor concentration thresholds (OTCs) were established by the three-alternative forced choice method (3-AFC). Following a previous published methodology, samples were analyzed and results showed that the advanced treatment (Ultrafiltration followed by reverse osmosis) line removes more efficiently 1,4-dioxane, alkyl dioxanes and dioxolanes (80 ± 6% for 1,4-dioxane, 97 ± 7% for 5,5-DMD and 100 ± 0% for 2,5,5-TMD) than the upgraded conventional treatment line (ozonation followed by granular activated carbon filters) (-12 ± 50%, 25 ± 62% and 50 ± 51% respectively), where some desorption processes were eventually observed. From the monitoring study, results suggest that the presence of 1,4-dioxane is not only due to spills, but also from other sources of contamination. Whereas dioxolanes almost completely disappeared in time, 1,4-dioxane's concentrations remained low and fluctuant. A background concentration of 1,4-dioxane in surface waters (∼1 μg/L) has been determined with a relevant concentration up to 11.6 μg/L of 1,4-dioxane in groundwater. The perception values for some of the studied compounds were extremely low (few ng/L only), which confirms the relevancy of this group of compounds as malodorous agents in waters.
在过去的几年中，1,4-二恶烷和烷基-1,3-二恶烷和二恶烷已被检测并确认为导致西班牙东北部加泰罗尼亚的 Llobregat 河及其含水层发生多次污染事件的原因。树脂制造工厂的溢油和废水排放物沿河流扩散，并到达饮用水处理厂（DWTP），从而释放到环境中，这是一个令人关注的主要问题，以研究这些化合物，以保护环境和公共健康。在这项研究中，进行了四个季节性采样活动，以确定 DWTP 各个步骤对二恶烷和二恶烷的去除效率，包括臭氧氧化，颗粒活性炭过滤器，超滤和反渗透步骤的处理。此外，在 DWTP 进行了超过两年的时间里，每周对原水，地下水和成品水中的 1,4-二恶烷和烷基-1,3-二恶烷和二恶烷进行采样监测。通过三选一强制选择法（3-AFC）建立了水气味浓度阈值（OTC）。按照先前公布的方法，对样品进行了分析，结果表明，先进的处理（超滤后反渗透）线比升级的常规处理线（臭氧氧化后颗粒活性炭过滤器）更有效地去除 1,4-二恶烷，烷基二恶烷和二恶烷（80±6％用于 1,4-二恶烷，97±7％用于 5,5-DMD 和 100±0％用于 2,5,5-TMD）（-12±50％，25±62％和 50±51％），最终观察到一些解吸过程。从监测研究中可以看出，1,4-二恶烷的存在不仅是由于溢油，而且还来自其他污染源。尽管二恶烷几乎完全消失了，但 1,4-二恶烷的浓度仍然较低且波动较大。已确定地表水（约 1μg/L）中 1,4-二恶烷的背景浓度高达 11.6μg/L 的地下水。所研究的某些化合物的感知值极低（仅几个 ng/L），这证实了该化合物组作为水中异味剂的相关性。
