Perfluoroalkyl acid transformation and mitigation by nNiFe-activated carbon nanocomposites in steady-state flow column studies  

作　　者：Mahsa Modiri-Gharehveran Younjeong Choi Jenny E.Zenobio Linda S.Lee 

机构地区：[1]Department of Agronomy,Purdue University,West Lafayette,IN 47907,USA [2]Interdisciplinary Ecological Sciences&Engineering,Purdue University,West Lafayette,IN 47907,USA

出　　处：《Journal of Environmental Sciences》2023年第5期678-687,共10页环境科学学报（英文版）

基　　金：funded by the Strategic Environmental Research and Development Program(No.SERDP/ER-2426);Geosyntec and the USDA National Institute of Food and Agriculture Hatch Funds Accession No.1006516.

摘　　要：The ongoing contamination of groundwater with per-and polyfluoroalkyl substances(PFAS)has resulted in a global and rapidly growing interest in PFAS groundwater remediation.Preferred technologies that lead to PFAS destruction are often limited by not addressing all PFAS,being energy-intensive or not being suited for in-situ application.We developed nNiFeactivated carbon(AC)nanocomposites and demonstrated varying degrees of PFAS reduction and fluoride generation with these nanocomposites in batch reactors for several PFAS.Here we explore nNiFe-AC’s effectiveness to transform perfluoroalkyl acid acids(PFAAs)under steady-state flow(0.0044 to 0.15 mL/min)in nNiFe-AC:sand packed columns.Column experiments included,two perfluorooctane sulfonate(PFOS)in deionized water and two PFAA mixtures in deionized water or bicarbonate buffer containing five perfluoroalkyl carboxylates(PFCAs,C5-C9)and three perfluoroalkyl sulfonates(PFSAs,C4,C6 and C8)at temperatures of 50 or 60℃ were evaluated.PFOS transformation was similar in PFOS-only and PFAA mixture column experiments.Overall,%PFAA transformation under flow conditions exceeded what we observed previously in batch reactors with up to 53%transformation of a PFAA mixture with∼8%defluorination.Longer chain PFAS dominated the PFAAs transformed and a bicarbonate matrix appeared to reduce overall transformation.PFAA breakthrough was slower than predicted from only sorption due to transformation;some longer chain PFAS like PFOS did not breakthrough.Here,nNiFe-AC technology with both in-situ and ex-situ potential application was shown to be a plausible part of a treatment train needed to address the ongoing challenge for cleaning up PFAS-contaminated waters.

关 键 词：PFAAs PFAS Zero valent iron Nanoparticles REMEDIATION GROUNDWATER 

分 类 号：X523[环境科学与工程—环境工程]