Nine per- and polyfluoroalkyl substances (PFASs), including six perfluoroalkyl carboxylic acids (PFCAs) and three perfluoroalkyl sulfonic acids (PFSAs), were tested to find their adsorption selectivity from surface water and the feasibility of the powder activated carbon (PAC) process between the perchlorination and coagulation processes by operating parameters such as mixing intensity, dosage, contact time, initial pH, and concentration of perchlorination. The removal efficiency of four types of PAC revealed that the coal-based activated carbon was clearly advanced for all of the PFASs, and the thermal regenerated PAC did not exhibit a significant reduction in adsorption capacity. The longer carbon chain or the higher molecular weight (MW) obtained a higher adsorption capacity and the MW exhibited a more proportional relationship with the removal efficiency than the carbon chain number, regardless of the PFCA and PFSA species. Approximately 80% and 90% equilibria were accomplished within 60 and 120 min for the long chain carbon PFAS, respectively, while for the short chain PFAS, 240 min was required to reach 85% equilibrium. The effect of mixing intensity (rpm) was not considered for the removal of the PFAS, although it was relatively influenced in the short PFAS species. Due to the surface charge of the PAC and the properties of protonation of the PFASs, the acid condition increased the PFASs’ adsorption capacity. The prechlorination decreased the removal efficiency, and the reduction rate was more significantly influenced for the short chain PFAS than for the long chain PFAS.

中文翻译：

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使用粉末活性炭对地表水中短和长全氟和多氟烷基物质 (PFAS) 的吸附选择性

测试了九种全氟和多氟烷基物质 (PFAS)，包括六种全氟烷基羧酸 (PFCA) 和三种全氟烷基磺酸 (PFSA)，以发现它们从地表水中的吸附选择性以及粉末活性炭 (PAC) 工艺的可行性。通过混合强度、剂量、接触时间、初始 pH 值和高氯化浓度等操作参数来控制高氯化和混凝过程。四种 PAC 的去除效率表明，煤基活性炭对所有 PFAS 都有明显的提升，而热再生 PAC 的吸附能力没有显着降低。更长的碳链或更高的分子量 (MW) 获得更高的吸附容量，并且 MW 与去除效率的比例关系比碳链数更显着，而与 PFCA 和 PFSA 种类无关。对于长链碳 PFAS，分别在 60 和 120 分钟内实现了大约 80% 和 90% 的平衡，而对于短链 PFAS，需要 240 分钟才能达到 85% 的平衡。混合强度 (rpm) 的影响没有考虑到 PFAS 的去除，尽管它在短 PFAS 物种中受到相对影响。由于 PAC 的表面电荷和 PFAS 质子化的特性，酸性条件增加了 PFAS 的吸附能力。预氯化降低了去除效率，