School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, South Australia 5064, Australia.
CSIRO Land and Water, PMB 2, Glen Osmond, SA 5064, Australia.
Sci Total Environ. 2023 Jun 1;875:162653. doi: 10.1016/j.scitotenv.2023.162653. Epub 2023 Mar 7.
Removal of per- and polyfluoroalkyl substances (PFASs) from water or their immobilization in soil using carbon-based sorbents is one of the cost-effective techniques. Considering the variety of carbon-based sorbents, identifying the key sorbent properties responsible for PFASs removal from solution or immobilization in the soil can assist in the selection of the best sorbents for management of contaminated sites. This study evaluated the performance of 28 carbon-based sorbents including granular and powdered activated carbon (GAC and PAC), mixed mode carbon mineral material, biochars, and graphene-based materials (GNBs). The sorbents were characterized for a range of physical and chemical properties. PFASs' sorption from an AFFF-spiked solution was examined via a batch experiment, while their ability to immobilize PFASs in soil was tested following mixing, incubation and extraction using the Australian Standard Leaching Procedure. Both soil and solution were treated with 1 % w/w sorbents. Comparing different carbon-based materials, PAC, mixed mode carbon mineral material and GAC were the most effective in sorbing PFASs in both solution and soil. Among the different physical characteristics measured, the sorption of long-chain and more hydrophobic PFASs in both soil and solution was best correlated with sorbent surface area measured using methylene blue, which highlights the importance of mesopores in PFASs sorption. Iodine number was found to be a better indicator of the sorption of short-chain and more hydrophilic PFASs from solution but was found to be poorly correlated with PFASs immobilization in soil for activated carbons. Sorbents with a net positive charge performed better than those with a net negative charge, or no net charge. This study showed that surface area measured by methylene blue and surface charge are the best indicators of sorbent performance with respect to sorption/reducing leaching of PFASs. These properties may be helpful in selecting sorbents for PFASs remediation of soils/waters.
使用基于碳的吸附剂从水中去除全氟和多氟烷基物质（PFASs）或将其固定在土壤中是一种具有成本效益的技术。考虑到各种基于碳的吸附剂，确定负责从溶液中去除 PFASs 或固定在土壤中的关键吸附剂特性，可以帮助选择用于管理污染场地的最佳吸附剂。本研究评估了 28 种基于碳的吸附剂的性能，包括颗粒状和粉末状活性炭（GAC 和 PAC）、混合模式碳矿物质材料、生物炭和基于石墨烯的材料（GNBs）。对吸附剂进行了一系列物理和化学性质的表征。通过批量实验研究了 AFFF 污染溶液中 PFASs 的吸附情况，同时通过混合、孵育和使用澳大利亚标准浸出程序提取来测试了它们在土壤中固定 PFASs 的能力。土壤和溶液均以 1%w/w 的吸附剂处理。比较不同的碳基材料，PAC、混合模式碳矿物质材料和 GAC 在溶液和土壤中吸附 PFASs 的效果最为显著。在所测量的不同物理特性中，长链和疏水性更强的 PFASs 在土壤和溶液中的吸附与使用亚甲蓝测量的吸附剂表面积相关性最好，这突出了介孔在 PFASs 吸附中的重要性。碘值被发现是从溶液中吸附短链和疏水性更强的 PFASs 的更好指标，但对于活性炭在土壤中固定 PFASs 的相关性较差。带净正电荷的吸附剂比带净负电荷或不带净电荷的吸附剂表现更好。本研究表明，亚甲蓝测量的表面积和表面电荷是吸附剂性能的最佳指标，与 PFASs 的吸附/减少浸出有关。这些特性可能有助于选择用于修复土壤/水中 PFASs 的吸附剂。
