TY - JOUR
T1 - Metal sorption by biochars
T2 - A trade-off between phosphate and carbonate concentration as governed by pyrolysis conditions
AU - Van Poucke, R.
AU - Allaert, S.
AU - Ok, Yong Sik
AU - Pala, M.
AU - Ronsse, F.
AU - Tack, F. M.G.
AU - Meers, E.
PY - 2019/9/15
Y1 - 2019/9/15
N2 - Three feedstocks, pine wood, grass and cow manure, were pyrolyzed under various conditions and tested on their ability to sorb metals in aquatic systems. The feedstocks were pyrolyzed at 2 different temperatures (350 °C and 550 °C) and 2 different residence times (10 and 60 min) and resulting biochars were assessed on their capability to immobilize Pb, Cu, Cd and Zn. Manure-based chars, and to a lesser extent grass-based chars, featured high concentrations of phosphates and carbonates. These anions play an important role in metal sorption because they form insoluble complexes with the metals. Washing reduced the concentration of these anions, leading to a reduced sorption of metals by the biochar. The carbonate concentration on the biochars’ surface increased at higher reactor temperature and longer residence times. The opposite trend was observed for the phosphate concentration and the cation exchange capacity. Accordingly, the optimal temperature-residence time combination for sorption was a trade-off between these properties. Biochar produced from cow manure and pyrolyzed at 550 °C for 10 min showed the best sorption for all metals considered.
AB - Three feedstocks, pine wood, grass and cow manure, were pyrolyzed under various conditions and tested on their ability to sorb metals in aquatic systems. The feedstocks were pyrolyzed at 2 different temperatures (350 °C and 550 °C) and 2 different residence times (10 and 60 min) and resulting biochars were assessed on their capability to immobilize Pb, Cu, Cd and Zn. Manure-based chars, and to a lesser extent grass-based chars, featured high concentrations of phosphates and carbonates. These anions play an important role in metal sorption because they form insoluble complexes with the metals. Washing reduced the concentration of these anions, leading to a reduced sorption of metals by the biochar. The carbonate concentration on the biochars’ surface increased at higher reactor temperature and longer residence times. The opposite trend was observed for the phosphate concentration and the cation exchange capacity. Accordingly, the optimal temperature-residence time combination for sorption was a trade-off between these properties. Biochar produced from cow manure and pyrolyzed at 550 °C for 10 min showed the best sorption for all metals considered.
KW - Carbonates
KW - Cow manure biochar
KW - Metal sorption
KW - Phosphates
KW - Pyrolysis conditions
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U2 - 10.1016/j.jenvman.2019.05.112
DO - 10.1016/j.jenvman.2019.05.112
M3 - Article
C2 - 31202015
AN - SCOPUS:85067262649
VL - 246
SP - 496
EP - 504
JO - Journal of Environmental Management
JF - Journal of Environmental Management
SN - 0301-4797
ER -