School of Civil and Environmental Engineering, Cornell University, Ithaca, NY, 14853, USA.
Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA.
Water Res. 2020 Apr 15;173:115551. doi: 10.1016/j.watres.2020.115551. Epub 2020 Jan 27.
The performance of adsorbents for the removal of organic micropollutants (MPs) from water can be influenced by the presence of water matrix constituents. The objective of this research was to evaluate the influence of water matrix constituents on the performance of coconut-shell activated carbon (CCAC), porous β-cyclodextrin polymer (CDP), and CDP coated on cellulose microcrystal (CDP@CMC) adsorbents. MP removals were measured in batch experiments for a mixture of 90 MP at 1 μg L and MP breakthrough was measured in rapid small-scale column test (RSSCT) experiments for a mixture of 15 MP at 500 ng L. All experiments were performed first with nanopure water, and subsequently with six different water samples collected from two separate groundwater, surface water, and wastewater effluent sources. The results of batch and RSSCT experiments demonstrate more rapid adsorption kinetics and less adsorption inhibition in the presence of matrix constituents for CDP adsorbents relative to CCAC. Further, the treatment capacity of CDP@CMC in the RSSCT experiments was higher than that of CCAC, particularly in more complex water matrices. Statistical analyses were performed to investigate associations between adsorption inhibition among groups of MPs and the concentrations of specific water matrix constituents. For CCAC, adsorption inhibition was observed for all MPs and was primarily attributed to the presence of dissolved organic matter with molar weight less than 1000 Da. For CDP adsorbents, adsorption inhibition was primarily observed for cationic MPs and was attributed to the screening of the negative surface charge of CDP by inorganic ions in water samples with high ionic strength. These data further demonstrate the value of CDP as an alternative adsorbent to CCAC for the removal of MPs during water and wastewater treatment.
水中有机微污染物（MPs）的去除效果可能会受到水基质成分的影响。本研究旨在评估水基质成分对椰子壳活性炭（CCAC）、多孔β-环糊精聚合物（CDP）和纤维素微晶负载 CDP（CDP@CMC）三种吸附剂去除 MPs 性能的影响。通过批量实验测量了 90 种 MPs 浓度为 1μg/L 混合物的 MP 去除率，通过快速小柱试验（RSSCT）测量了 15 种 MPs 浓度为 500ng/L 混合物的 MP 穿透率。所有实验均首先在去离子水中进行，然后在六种不同水源（地下水、地表水和废水）采集的水样中进行。批量实验和 RSSCT 实验的结果表明，与 CCAC 相比，CDP 吸附剂在存在基质成分的情况下，具有更快的吸附动力学和更少的吸附抑制作用。此外，在 RSSCT 实验中，CDP@CMC 的处理能力高于 CCAC，尤其是在更复杂的水基质中。进行了统计分析，以研究各组 MPs 之间的吸附抑制与特定水基质成分浓度之间的关系。对于 CCAC，所有 MPs 都观察到了吸附抑制，这主要归因于分子量小于 1000Da 的溶解有机物的存在。对于 CDP 吸附剂，主要观察到阳离子 MPs 的吸附抑制，这归因于水样中高离子强度下无机离子对 CDP 负表面电荷的屏蔽。这些数据进一步证明了 CDP 作为替代 CCAC 的吸附剂在水和废水处理中去除 MPs 的价值。
