@article{5c62bb5d8af643a78dd472a917141c0c,
title = "Adsorption of perfluorooctanoic acid from water by pH-modulated Br{\"o}nsted acid and base sites in mesoporous hafnium oxide ceramics",
abstract = "Per- and polyfluoroalkyl substances (PFAS) are increasingly appearing in drinking water sources globally. Our work focuses specifically on the adsorption of the legacy perfluorooctanoic acid (PFOA) using mesoporous hafnium oxide (MHO) ceramic synthesized via a sol-gel process. Experiments were performed at varying pH to determine the effect of surface charge on adsorption capacity of PFOA by MHO, and to postulate adsorption behavior. At pH 2.3, the adsorption capacity of PFOA on MHO was 20.9 mg/g, whereas at a higher pH of 6.3, it was much lower at 9.2 mg/g. This was due to increased coulombic attractions at lower pH between the positively charged conjugate acid active sites on MHO surface and negatively charged deprotonated PFOA anion in solution. After adsorption, the solid MHO was regenerated via calcination, reducing the amount of toxic solid waste to be disposed since the adsorbent is regenerated, and the PFOA is completely removed.",
keywords = "Chemical Engineering, Environmental Chemistry, Materials Chemistry, Materials Science",
author = "Hussain, {Fatima A.} and Janisse, {Samuel E.} and Heffern, {Marie C.} and Maureen Kinyua and Vel{\'a}zquez, {Jes{\'u}s M.}",
note = "Funding Information: We would like to acknowledge the California department of Resources, Recycling, and Recovery (CalRecycle) award number DRR18040 for funding this project, University of California Davis for startup funding for this project, NSF-MRI grant DMR-1725618 for the use of the Thermofisher Quattro environmental scanning electron microscope at the Advanced Materials Characterization and Testing Laboratory (AMCAT) at UC Davis. We would like to acknowledge support from the Cottrell Scholar program supported by the Research Corporation for Science Advancement (RCSA 26780) as well as the National Science Foundation Faculty Early Career Development program (DMR-2044403). We would also like to acknowledge NSF Grant 2048265. Fatima A Hussain: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Validation, Visualization, Writing ? original draft, Writing ? review & editing. Samuel E. Janisse: Data Curation, Formal Analysis, Methodology, Visualization, Writing ? review & editing. Marie C. Heffern: Resources, Supervision, Writing ? review & editing. Maureen Kinyua: Supervision, Funding acquisition, Writing ? original draft, Writing ? review & editing. Jes?s M. Vel?zquez: Conceptualization, Methodology, Resources, Supervision, Funding acquisition, Writing ? original draft, Writing ? review & editing. The authors declare no competing interests. One or more of the authors of this paper self-identifies as an underrepresented ethnic minority in science. One or more of the authors of this paper received support from a program designed to increase minority representation in science. While citing references scientifically relevant for this work, we also actively worked to promote gender balance in our reference list. Funding Information: We would like to acknowledge the California department of Resources, Recycling, and Recovery (CalRecycle) award number DRR18040 for funding this project, University of California Davis for startup funding for this project, NSF- MRI grant DMR-1725618 for the use of the Thermofisher Quattro environmental scanning electron microscope at the Advanced Materials Characterization and Testing Laboratory ( AMCAT ) at UC Davis. We would like to acknowledge support from the Cottrell Scholar program supported by the Research Corporation for Science Advancement (RCSA 26780) as well as the National Science Foundation Faculty Early Career Development program (DMR-2044403). We would also like to acknowledge NSF Grant 2048265. Publisher Copyright: {\textcopyright} 2022 The Authors",
year = "2022",
month = apr,
day = "15",
doi = "10.1016/j.isci.2022.104138",
language = "English (US)",
volume = "25",
journal = "iScience",
issn = "2589-0042",
publisher = "Elsevier Inc.",
number = "4",
}