Data from: Simultaneous removal of fluoride and arsenic in geothermal water in Tibet using modified yak dung biochar as an adsorbent

Fluoride (F) and arsenic (As) are two typical and harmful elements that
are found in high concentrations in geothermal water in Tibet. In the
present work, yak dung, an abundant source of biomass energy in Tibet, was
made into biochars (BC1, BC2 and BC3) by pyrolysis under different
conditions, and the better biochar was modified by FeCl2 (Fe-BC3). The
adsorption conditions were optimized to adsorb F and As in geothermal
water. The results showed that BC3 can remove 90% F- and 20% As(V), which
is the best effect of the three initial biochars. Fe-BC3 could remove 94%
F- and 99.45% As(V) under the same conditions as BC3, which was an
adsorbent dosage 10 g/L, pH 5-6 and temperature of 25 °C. It was also
demonstrated that the removal rate did not decrease at 80 °C. A
quasi-second-order kinetic model best described the adsorption behavior of
ions on the surface of the biochar. The maximum adsorption capacity of F-
and As(V) on Fe-BC3 was 3.928 mg/g and 2.926 mg/g, respectively. The
features of Fe-BC3 were characterized by X-Ray Diffraction (XRD), Fourier
Transform Infrared (FTIR), Brunauer-Emmett-Teller (BET), Energy Dispersive
Spectrometer (EDS), and Scanning Electron Microscopy (SEM) to understand
the adsorption process.