TY - JOUR
T1 - Mechanisms of antimony adsorption onto soybean stover-derived biochar in aqueous solutions
AU - Vithanage, Meththika
AU - Rajapaksha, Anushka Upamali
AU - Ahmad, Mahtab
AU - Uchimiya, Minori
AU - Dou, Xiaomin
AU - Alessi, Daniel S.
AU - Ok, Yong Sik
N1 - Funding Information:
This research was supported by Basic Science Research Foundation through the National Research Foundation (NRF) of Korea, funded by the Ministry of Education, Science and Technology ( 2012R1A1B3001409 ). The instrumental analysis was partly supported by the Korea Basic Science Institute and the Central Laboratory of the Kangwon National University in Korea.
Publisher Copyright:
© 2014 Elsevier Ltd.
PY - 2015/3/5
Y1 - 2015/3/5
N2 - Limited mechanistic knowledge is available on the interaction of biochar with trace elements (Sb and As) that exist predominantly as oxoanions. Soybean stover biochars were produced at 300°C (SBC300) and 700°C (SBC700), and characterized by BET, Boehm titration, FT-IR, NMR and Raman spectroscopy. Bound protons were quantified by potentiometric titration, and two acidic sites were used to model biochar by the surface complexation modeling based on Boehm titration and NMR observations. The zero point of charge was observed at pH 7.20 and 7.75 for SBC300 and SBC700, respectively. Neither antimonate (Sb(V)) nor antimonite (Sb(III)) showed ionic strength dependency (0.1, 0.01 and 0.001M NaNO3), indicating inner sphere complexation. Greater adsorption of Sb(III) and Sb(V) was observed for SBC300 having higher -OH content than SBC700. Sb(III) removal (85%) was greater than Sb(V) removal (68%). Maximum adsorption density for Sb(III) was calculated as 1.88×10-6molm-2. The Triple Layer Model (TLM) successfully described surface complexation of Sb onto soybean stover-derived biochar at pH 4-9, and suggested the formation of monodentate mononuclear and binuclear complexes. Spectroscopic investigations by Raman, FT-IR and XPS further confirmed strong chemisorptive binding of Sb to biochar surfaces.
AB - Limited mechanistic knowledge is available on the interaction of biochar with trace elements (Sb and As) that exist predominantly as oxoanions. Soybean stover biochars were produced at 300°C (SBC300) and 700°C (SBC700), and characterized by BET, Boehm titration, FT-IR, NMR and Raman spectroscopy. Bound protons were quantified by potentiometric titration, and two acidic sites were used to model biochar by the surface complexation modeling based on Boehm titration and NMR observations. The zero point of charge was observed at pH 7.20 and 7.75 for SBC300 and SBC700, respectively. Neither antimonate (Sb(V)) nor antimonite (Sb(III)) showed ionic strength dependency (0.1, 0.01 and 0.001M NaNO3), indicating inner sphere complexation. Greater adsorption of Sb(III) and Sb(V) was observed for SBC300 having higher -OH content than SBC700. Sb(III) removal (85%) was greater than Sb(V) removal (68%). Maximum adsorption density for Sb(III) was calculated as 1.88×10-6molm-2. The Triple Layer Model (TLM) successfully described surface complexation of Sb onto soybean stover-derived biochar at pH 4-9, and suggested the formation of monodentate mononuclear and binuclear complexes. Spectroscopic investigations by Raman, FT-IR and XPS further confirmed strong chemisorptive binding of Sb to biochar surfaces.
KW - Black carbon
KW - Charcoal
KW - Slow pyrolysis
KW - Surface charge
KW - Surface complexation model
UR - http://www.scopus.com/inward/record.url?scp=84921047190&partnerID=8YFLogxK
U2 - 10.1016/j.jenvman.2014.11.005
DO - 10.1016/j.jenvman.2014.11.005
M3 - Article
C2 - 25602696
AN - SCOPUS:84921047190
SN - 0301-4797
VL - 151
SP - 443
EP - 449
JO - Journal of Environmental Management
JF - Journal of Environmental Management
ER -