Journal article

Enhanced Defluoridation of Water Using Zirconium-Coated Pumice in Fixed-Bed Adsorption Columns


Authors listGeleta, Wondwosen Sime; Alemayehu, Esayas; Lennartz, Bernd

Publication year2021

JournalMaterials

Volume number14

Issue number20

eISSN1996-1944

Open access statusGold

DOI Linkhttps://doi.org/10.3390/ma14206145

PublisherMDPI


Abstract
Millions of people across the globe suffer from health issues related to high fluoride levels in drinking water. The purpose of this study was to test modified pumice as an adsorbent for the purification of fluoride-containing waters. The adsorption of fluoride onto zirconium-coated pumice (Zr-Pu) adsorbent was examined in fixed-bed adsorption columns. The coating of zirconium on the surface of VPum was revealed by X-ray diffractometer (XRD), Inductively coupled plasma-optical emission spectroscopy (ICP-EOS), and X-ray fluorescence (XRF) techniques. The degree of surface modification with the enhanced porosity of Zr-Pu was evident from the recorded scanning electron microscope (SEM) micrographs. The Brunauer-Emmett-Teller (BET) analysis confirmed the enhancement of the specific surface area of VPum after modification. The Fourier transform infrared (FTIR) examinations of VPum and Zr-Pu before and after adsorption did not reveal any significant spectrum changes. The pH drift method showed that VPum and Zr-Pu have positive charges at pH(PZC) lower than 7.3 and 6.5, respectively. Zr-Pu yielded a higher adsorption capacity of 225 mg/kg (2.05 times the adsorption capacity of VPum: 110 mg/kg), at pH = 2 and volumetric flow rate (Q(O)) of 1.25 mL/min. Breakthrough time increases with decreasing pH and flow rate. The experimental adsorption data was well-matched by the Thomas and Adams-Bohart models with correlation coefficients (R-2) of & GE; 0.980 (Zr-Pu) and & GE; 0.897 (VPum), confirming that both models are suitable tools to design fixed-bed column systems using volcanic rock materials. Overall, coating pumice with zirconium improved the defluoridation capacity of pumice; hence, a Zr-Pu-packed fixed-bed can be applied for defluoridation of excess fluoride from groundwater. However, additional investigations on, for instance, the influences of competing ions are advisable to draw explicit conclusions.




Citation Styles

Harvard Citation styleGeleta, W., Alemayehu, E. and Lennartz, B. (2021) Enhanced Defluoridation of Water Using Zirconium-Coated Pumice in Fixed-Bed Adsorption Columns, Materials, 14(20), Article 6145. https://doi.org/10.3390/ma14206145

APA Citation styleGeleta, W., Alemayehu, E., & Lennartz, B. (2021). Enhanced Defluoridation of Water Using Zirconium-Coated Pumice in Fixed-Bed Adsorption Columns. Materials. 14(20), Article 6145. https://doi.org/10.3390/ma14206145



Keywords


BREAKTHROUGHDEFLUORIDATIONDRINKING-WATERFLUORIDEFLUORIDE REMOVALION-EXCHANGEREVERSE-OSMOSISVPumzirconium-coated pumice

Last updated on 2025-10-06 at 11:32