Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO 80401, United States.
School of Sustainable Engineering and the Built Environment (SSEBE), Arizona State University (ASU), Tempe, AZ 85287, United States.
Water Res. 2023 Sep 1;243:120324. doi: 10.1016/j.watres.2023.120324. Epub 2023 Jul 8.
Anion exchange resin (AER) and granular activated carbon (GAC) have emerged as prominent technologies for treatment of waters contaminated with per- and polyfluoroalkyl substances (PFASs). This study compares the life cycle environmental impacts and life cycle costs of remediating PFAS-contaminated groundwater with these competing technologies, using field pilot data to inform model inputs. Comparative analysis indicates that AER systems employing single-use "PFAS-selective" resins have lower environmental impacts and costs than systems using regenerable resins or GAC adsorbents, supporting its use in future remediation efforts. Use of GAC operated as a single-use adsorbent led to the highest emissions as well as the highest treatment costs, with thermally-reactivated GAC proving to be less impactful than regenerable AER treatment. Sensitivity analyses highlighted the dominance of media usage rate (MUR), which is highly dependent on the selected PFAS treatment goals, to determine environmental impacts and costs over a 30-year system life cycle. Selection of very stringent changeout criteria (e.g., detection of any PFASs in effluent) significantly reduces the advantages of single-use resins. For regenerable AER, environmental impacts were dominated by management of the PFAS-contaminated brine/co-solvent waste stream used to regenerate the adsorbent, as well as the cosolvent content of the regenerant mixture and the cosolvent recovery efficiency achieved via on-site distillation. High impacts estimated for GAC adsorption, the result of high MUR relative to ion exchange media, can be significantly reduced if spent adsorbents are reused after thermal reactivation, but impacts are still greater than those predicted for single-use ion exchange systems. Findings are expected to hold across a range of diverse sites, including drinking water systems treating more dilute sources of PFAS contamination, as PFAS breakthrough was not found to be highly sensitive to sourcewater PFAS concentrations.
阴离子交换树脂 (AER) 和颗粒状活性炭 (GAC) 已成为处理受全氟和多氟烷基物质 (PFAS) 污染的水的重要技术。本研究使用现场试点数据为模型输入提供信息，比较了这些竞争技术修复受 PFAS 污染地下水的生命周期环境影响和生命周期成本。比较分析表明，使用一次性“PFAS 选择性”树脂的 AER 系统比使用可再生树脂或 GAC 吸附剂的系统具有更低的环境影响和成本，支持将其用于未来的修复工作。使用作为一次性吸附剂操作的 GAC 导致最高的排放以及最高的处理成本，而热再生 GAC 被证明比可再生 AER 处理的影响更小。敏感性分析强调了介质使用率 (MUR) 的主导地位，MUR 高度依赖于所选的 PFAS 处理目标，以确定 30 年系统生命周期内的环境影响和成本。选择非常严格的更换标准（例如，检测出任何 PFAS 都在流出物中）会显著降低一次性树脂的优势。对于可再生的 AER，环境影响主要由管理用于再生吸附剂的 PFAS 污染盐水/共溶剂废水流以及再生剂混合物中的共溶剂含量和通过现场蒸馏实现的共溶剂回收率决定。如果在热再生后再利用用过的吸附剂，那么对 GAC 吸附的高估计影响（由于与离子交换介质相比 MUR 较高所致）可以显著降低，但影响仍大于预测的一次性离子交换系统。预计这些发现将适用于一系列不同的地点，包括处理更稀 PFAS 污染水源的饮用水系统，因为 PFAS 突破对水源 PFAS 浓度的敏感性不高。
