Performance and mechanism of fluoride adsorption from groundwater
by lanthanum-modified pomelo peel biochar
Received: 15 November 2017 /Accepted: 12 March 2018 /Published online: 21 March 2018
Springer-Verlag GmbH Germany, part of Springer Nature 2018
To obtain an economical and effective adsorbent for fluoride removal, lanthanum-loaded pomelo peel biochar (PPBC-La) was
synthesized using a facile approach. The batch adsorption experiments were investigated to determine adsorbent performance.
The PPBC-La and its pristine biochar (PPBC) were characterized by scanning electronic microscopy (SEM), zeta potential,
Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS)
methods. Experimental results showed that the adsorption data were described well by the pseudo-second-order kinetic and
Freundlich isotherm models. The maximum fluoride adsorption capacity for PPBC-La was found to be 19.86 mg/g at 25 °C and
pH 6.5. The PPBC-La worked well at pH 2.4–9.6 and carried positive charge at pH < 5.8. The presence of SO
had a slight effect on fluoride uptake except HCO
. The real groundwater study testified that 9.8 mg/L of fluoride was
removed effectively at 1.0 g/L of dosage and pH 5.2. The regeneration results revealed that the PPBC-La had a good reusability.
According to FTIR, XPS analysis and the anion exchange experiment, anions (NO
) exchange with fluoride ions was
mainly responsible for fluoride adsorption.
Keywords Pomelo peel
The presence of excess fluoride in drinking water has attracted
increasing concern due to its long-term adverse impacts on
human health (Dong and Wang 2016). For instance, the inges-
tion of excessive fluoride can cause dental and skeletal fluo-
rosis (Ozsvath 2009). Hence, the maximum fluoride level of
1.5 mg/L has been established by the World Health
Responsible editor: Guilherme L. Dotto
Electronic supplementary material The online version of this article
(https://doi.org/10.1007/s11356-018-1727-6) contains supplementary
material, which is available to authorized users.
* Nan Chen
School of Water Resources and Environment, China University of
Geosciences (Beijing), Beijing 100083, China
Key Laboratory of Groundwater Cycle and Environment Evolution
(China University of Geosciences (Beijing)), Ministry of Education,
Beijing 100083, China
School of Environment, Tsinghua University, Beijing 100084, China
Environmental Science and Pollution Research (2018) 25:15326–15335
Organization (WHO) for protecting human health (Yu et al.
sive fluoride from aqueous solution, including adsorption, re-
verse osmosis, nanofiltration and electrodialysis (Mohapatra
et al. 2009). Adsorption, among these methods, is considered
to be a promising method for fluoride removal owing to its
low cost, effectiveness, simplicity of operation (Prabhu et al.
2016a). Many adsorbents have been prepared for adsorbing
fluoride from aqueous solution, including expensive metal
compounds (Yu et al. 2015b;Adaketal.2017) and low cost
materials, for instance activated carbon (Singh et al. 2017),
clay (Zhang et al. 2016), and zeolite (Sun et al. 2011).
Recently, various biomass-based materials have been de-
veloped to remove fluoride due to their low cost and availabil-
ity, such as, bamboo charcoal (Wendimu et al. 2017), bone
chars (Rojas-Mayorga et al. 2015), pine sawdust
(Vázquez-Guerrero et al. 2016), sucrose carbon (Prabhu
et al. 2017) and chitosan (Ma et al. 2014). Pomelo peel, an
agricultural waste, is produced in large amounts by fruit pro-
cessing plants or human eating. Most of them are discarded
directly and cannot be utilized fully. Pomelo peel contains
pectin, cellulose, hemicellulose, lignin, glucose and fructose,