Department of Civil Engineering and Architecture, University of Catania, Viale A. Doria 6, 95125, Catania, Italy.
Department of Chemical and Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ, 85721, USA; Agilent Technologies Inc., 2850 Centerville Road, Wilmington, DE, 19808, USA.
Water Res. 2018 Nov 15;145:667-677. doi: 10.1016/j.watres.2018.09.018. Epub 2018 Sep 6.
This study investigated, using rapid small-scale column testing, the breakthrough of dissolved organic matter (DOM) and eleven emerging organic contaminants (EOCs) during granular activated carbon (GAC) filtration of different water qualities, including wastewater, surface water and synthetic water (riverine organic matter dissolved in deionized water). Fluorescing organic matter was better adsorbed than UV absorbance at 254 nm (UV) and dissolved organic carbon (DOC) in all tested water. Furthermore, highest adsorption of DOM (in terms of DOC, UV and fluorescence) was observed during wastewater filtration. UV absorbing DOM had fast and similar breakthrough in surface water and synthetic water, whereas fluorescence breakthrough was very rapid only in synthetic water. PARAFAC modeling showed that different fluorescing components were differently adsorbed during GAC process. Particularly, fluorescing components with maxima intensity at higher excitation wavelengths, which are corresponding to humic-like fluorescence substances, were better removed than other components in all waters. As opposed to DOM, EOCs were better adsorbed during synthetic water filtration, whereas the fastest EOCs breakthrough was observed during filtration of wastewater, which was the water that determined the highest carbon fouling. Exception was represented by long-chained perfluoroalkylated substances (i.e., PFOA, PFDA and PFOS). Indeed, adsorption of these compounds resulted independent of water quality. In this study was also investigated the applicability of UV and fluorescing PARAFAC components to act as surrogates in predicting EOCs removal by GAC in different water matrices. Empirical linear correlation for the investigated EOCs were determined with UV and fluorescing components in all water qualities. However, fluorescence measurements resulted more sensitive than UV to predict EOC breakthrough during GAC adsorption. When the data from all water qualities was combined, good correlations between the microbial humic-like PARAFAC component and EOC removals were still observed and they resulted independent of water quality if considering only real water matrices (wastewater and surface water). On the contrary, correlations between EOC removals and UV removals were independent of water quality when combining data of surface waters and synthetic water, but a different correlation model was needed to predict EOCs breakthrough in wastewater.
本研究采用快速小柱试验，考察了不同水质（包括废水、地表水和合成水[河流水体有机物溶解在去离子水中]）中颗粒活性炭（GAC）过滤过程中溶解有机物（DOM）和 11 种新兴有机污染物（EOCs）的穿透情况。与 UV 吸收值 254nm（UV）和溶解有机碳（DOC）相比，所有测试水样中的荧光有机物都具有更好的吸附性能。此外，在废水过滤过程中，DOM（以 DOC、UV 和荧光计）的吸附量最大。UV 吸收 DOM 在地表水和合成水中的穿透速度较快且相似，而在合成水中，荧光穿透速度非常快。PARAFAC 模型表明，在 GAC 过程中，不同的荧光成分的吸附方式不同。特别是，在所有水样中，那些激发波长较大处荧光强度最大的荧光成分（对应于类腐殖质荧光物质）的去除效果优于其他成分。与 DOM 不同的是，EOCs 在合成水过滤过程中具有更好的吸附性能，而在废水过滤过程中，EOCs 的穿透速度最快，这也是导致碳污染最高的水样。长链全氟烷基物质（如 PFOA、PFDA 和 PFOS）则是个例外。实际上，这些化合物的吸附与水质无关。本研究还考察了 UV 和荧光 PARAFAC 成分在预测不同水质基质中 GAC 去除 EOCs 方面的适用性。在所有水样中，都确定了 UV 和荧光成分与所研究的 EOCs 之间的经验线性相关性。然而，与 UV 相比，荧光测量对预测 GAC 吸附过程中 EOC 的穿透更为敏感。当将所有水质的数据合并时，仍观察到微生物类腐殖质 PARAFAC 成分与 EOC 去除率之间存在良好的相关性，并且如果仅考虑实际水样（废水和地表水），它们与水质无关。相反，当将地表水和合成水的数据合并时，EOC 去除率与 UV 去除率之间的相关性与水质无关，但需要建立不同的相关模型来预测废水的 EOC 穿透。
