Fluoride adsorption onto Fe(III) modified montmorillonite was investigated using batch experiments. The effect of reaction time, pH, ionic strength and phosphate, as a competitive anion, was evaluated. Kinetics indicated that adsorption obeys a pseudo-first-order rate law which involves two steps. The fast one (bulk transport/surface reaction) occurs instantaneously. The slower (diffusion in pores) takes hours to complete. The adsorption rate increases by increasing the fluoride concentration and by decreasing pH. The presence of phosphate reduces fluoride adsorption and reveals that both ions are in competition for surface sites. The reduction in fluoride adsorption when phosphate is present depends on the order of adsorbate addition. The higher fluoride adsorption occurs when both anions are added simultaneously, whereas when either fluoride or phosphate is added first, the fluoride adsorption is lower. The presence of fluoride does not have a measurable effect on phosphate adsorption. The results obtained contribute to our understanding of the mobility of fluoride in surface water which has naturally high levels of fluoride, in both the presence and absence of phosphate.
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http://dx.doi.org/10.1016/j.jenvman.2012.01.019 | DOI Listing |
Int J Biol Macromol
January 2025
Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea. Electronic address:
This study describes the preparation of novel hybrid aerogels derived from gelatin (Gel), incorporating Br-functionalized zirconium-based metal-organic framework (UiO-66-Br; MOF) as modifying agent to effectively eliminate phosphate and fluoride ions from aqueous environments. The adsorption performance of MOF decorated Gel (Gel-xMOF) hybrid aerogels was investigated under different conditions, including agitation time, adsorbent dosage, solution pH, initial phosphate and fluoride concentrations, coexisting ions, and temperature. The functional groups of the gelatin network, coupled with UiO-66-Br, enhanced the adsorption performance of phosphate and fluoride ions from aqueous solutions.
View Article and Find Full Text PDFChemistry
January 2025
East China University of Science and Technology, School of Material Science & Engineering, P.O. Box 289, 130 Meilong Rd., 200237, Shanghai, CHINA.
Silicon/carbon (Si/C) materials have achieved commercial applications as a solution to the problems of large volume expansion and short lifespan of silicon-based anodes in lithium-ion batteries. However, the potential risk of structural fracture and localized differences in surface adsorption properties lead to difficulties in maintaining the structural integrity of Si/C anodes using conventional binders during repeated lithiation/delithiation. Herein, an aqueous binder (PVA-g-M) based on polyvinyl alcohol (PVA) grafted methacrylic acid (MAA) obtained by self-emulsifyingemulsion polymerization is reported.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China. Electronic address:
Developing efficient and cost-effective rare earth element-based electrocatalysts for water splitting remains a significant challenge. To address this, interface engineering and charge modulation strategies were employed to create a three-dimensional coral-like CeF/MoO heterostructure electrocatalyst, grown in situ on the multistage porous channels of carbonized sugarcane fiber (CSF). Integrating abundant CeF/MoO heterostructure interfaces and numerous oxygen vacancy defects significantly enhanced the catalyst's active sites and molecular activation capabilities.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
Environ Technol
January 2025
Department of Materials Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
This study synthesises expanded graphite (EG) from graphitised carbon from waste polyethylene terephthalate (PET) bottles. The adsorbent material was characterised using FTIR, XRF, XRD, SEM, Raman Spectroscopy, and BET surface area analysis. The synthesised EG defluorinated wastewater, utilising response surface methodology (RSM) for experimental design and optimisation.
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