TY - JOUR
T1 - Adsorption kinetics of magnetic biochar derived from peanut hull on removal of Cr (VI) from aqueous solution
T2 - Effects of production conditions and particle size
AU - Han, Yitong
AU - Cao, Xi
AU - Ouyang, Xin
AU - Sohi, Saran P.
AU - Chen, Jiawei
PY - 2016/2/1
Y1 - 2016/2/1
N2 - Magnetic biochar was made from peanut hull biomass using iron chloride in a simplified aqueous phase approach and pyrolysis at alternative peak temperatures (450-650 °C). Magnetic biochar showed an extreme capacity for adsorption of hexavalent chromium Cr (VI) from aqueous solution, which was 1-2 orders of magnitude higher compared to standard (non-magnetic) biochar from the same feedstock. Adsorption increased with pyrolysis temperature peaking at 77,542 mg kg-1 in the sample pyrolysed at 650 °C. In contrast to magnetic biochar, the low adsorption capacity of standard biochar decreased with increasing pyrolysis temperature. The fine particle size of magnetic biochar and low aqueous pH were also important for adsorption. Surfaces of products from batch adsorption experiments were characterized by scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, X-ray photoelectron spectroscopy and vibrating sample magnetometer. This revealed that γ-Fe2O3 was crucial to the properties (adsorbance and magnetism) of magnetic biochar. The removal mechanism was the Cr (VI) electrostatic attracted on protonated -OH on γ-Fe2O3 surface and it could be desorbed by alkaline solution. Findings suggest that pyrolysis has potential to create effective, magnetically recoverable adsorbents relevant to environmental application.
AB - Magnetic biochar was made from peanut hull biomass using iron chloride in a simplified aqueous phase approach and pyrolysis at alternative peak temperatures (450-650 °C). Magnetic biochar showed an extreme capacity for adsorption of hexavalent chromium Cr (VI) from aqueous solution, which was 1-2 orders of magnitude higher compared to standard (non-magnetic) biochar from the same feedstock. Adsorption increased with pyrolysis temperature peaking at 77,542 mg kg-1 in the sample pyrolysed at 650 °C. In contrast to magnetic biochar, the low adsorption capacity of standard biochar decreased with increasing pyrolysis temperature. The fine particle size of magnetic biochar and low aqueous pH were also important for adsorption. Surfaces of products from batch adsorption experiments were characterized by scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, X-ray photoelectron spectroscopy and vibrating sample magnetometer. This revealed that γ-Fe2O3 was crucial to the properties (adsorbance and magnetism) of magnetic biochar. The removal mechanism was the Cr (VI) electrostatic attracted on protonated -OH on γ-Fe2O3 surface and it could be desorbed by alkaline solution. Findings suggest that pyrolysis has potential to create effective, magnetically recoverable adsorbents relevant to environmental application.
KW - Adsorption and desorption
KW - Magnetic biochar
KW - Magnetic properties
KW - Particle size
KW - Pyrolysis temperature
UR - http://www.scopus.com/inward/record.url?scp=84959537553&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2015.11.050
DO - 10.1016/j.chemosphere.2015.11.050
M3 - Article
C2 - 26692510
AN - SCOPUS:84959537553
SN - 0045-6535
VL - 145
SP - 336
EP - 341
JO - Chemosphere
JF - Chemosphere
ER -