Fluoride removal by palm shell waste based powdered activated carbon vs. functionalized carbon with magnesium silicate: Implications for their application in water treatment

Choe Earn Choong, Kien Tiek Wong, Seok Byum Jang, In Wook Nah, Jaeyoung Choi, Shaliza Ibrahim, Yeomin Yoon, Min Jang

Research output: Contribution to journalArticlepeer-review

64 Scopus citations

Abstract

In this study, palm shell activated carbon powder (PSAC) and magnesium silicate (MgSiO3) modified PSAC (MPSAC) were thoroughly investigated for fluoride (F) adsorption. F adsorption isotherms showed that PSAC and MPSAC over-performed some other reported F adsorbents with adsorption capacities of 116 mg g−1 and 150 mg g−1, respectively. Interestingly, the MgSiO3 impregnated layer changed the adsorption behavior of F from monolayer to heterogeneous multilayer based on the Langmuir and Freundlich isotherm models verified by chi-square test (X2). Thermodynamic parameters indicated that the F adsorption on PSAC and MPSAC was spontaneous and exothermic. PSAC and MPSAC were characterized using FESEM-EDX, XRD, FTIR and XPS to investigate the F adsorption mechanism. Based on the regeneration tests using NaOH (0.01 M), PSAC exhibited poor regeneration (<20%) while MPSAC had steady adsorption efficiencies (∼70%) even after 5 regeneration cycles. This is due to highly polarized C–F bond was found on PSAC while Mg–F bond was distinguished on MPSAC, evidently denoting that the F adsorption is mainly resulted from the exchange of hydroxyl (-OH) group. It was concluded that PSAC would be a potential adsorbent for in-situ F groundwater remediation due to its capability to retain F without leaching out in a wide range pH. MPSAC would be an alternative adsorbent for ex-situ F water remediation because it can easily regenerate with NaOH solution. With the excellent F adsorption properties, both PSAC and MPSAC offer as promising adsorbents for F remediation in the aqueous phase.

Original languageEnglish
Article number124765
JournalChemosphere
Volume239
DOIs
StatePublished - Jan 2020

Bibliographical note

Publisher Copyright:
© 2019 Elsevier Ltd

Keywords

  • Adsorption
  • Fluoride
  • Magnesium silicate
  • Palm-shell activated carbon

Fingerprint

Dive into the research topics of 'Fluoride removal by palm shell waste based powdered activated carbon vs. functionalized carbon with magnesium silicate: Implications for their application in water treatment'. Together they form a unique fingerprint.

Cite this