TY - JOUR
T1 - Endogenous minerals have influences on surface electrochemistry and ion exchange properties of biochar
AU - Zhao, Ling
AU - Cao, Xinde
AU - Zheng, Wei
AU - Wang, Qun
AU - Yang, Fan
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China ( 21377081 , 21428702 ), Shanghai Science and Technology Commission ( 13231202502 ), and Shanghai Education Commission ( 14ZZ026 ). It also was supported by the State Key Laboratory of Pollution Control and Resource Reuse Foundation ( PCRRF12009 ).
Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015
Y1 - 2015
N2 - The feedstocks for biochar production are diverse and many of them contain various minerals in addition to being rich in carbon. Twelve types of biomass classified into 2 categories: Plant-based and municipal waste, were employed to produce biochars under 350°C and 500°C. Their pH, point of zero net charge (PZNC), zeta potential, cation and anion exchange capacity (CEC and AEC) were analyzed. The municipal waste-based biochars (MW-BC) had higher mineral levels than the plant-based biochars (PB-BC). However, the water soluble mineral levels were lower in the MW-BCs due to the dominant presence of less soluble minerals, such as CaCO3 and (Ca, Mg)3(PO4)2. The higher total minerals in MW-BCs accounted for the higher PZNC (5.47-9.95) than in PB-BCs (1.91-8.18), though the PZNCs of the PB-BCs increased more than that of the MW-BCs as the production temperature rose. The minerals had influence on the zeta potentials via affecting the negative charges of biochars and the ionic strength of solution. The organic functional groups in PB-BCs such as -COOH and -OH had a greater effect on the CEC and AEC, while the minerals had a greater effect on that of MW-BCs. The measured CEC and AEC values had a strong positive correlation with the total amount of soluble cations and anions, respectively. Results indicated that biochar surface charges depend not only on the organic functional groups, but also on the minerals present and to some extent, minerals have more influences on the surface electrochemistry and ion exchange properties of biochar.
AB - The feedstocks for biochar production are diverse and many of them contain various minerals in addition to being rich in carbon. Twelve types of biomass classified into 2 categories: Plant-based and municipal waste, were employed to produce biochars under 350°C and 500°C. Their pH, point of zero net charge (PZNC), zeta potential, cation and anion exchange capacity (CEC and AEC) were analyzed. The municipal waste-based biochars (MW-BC) had higher mineral levels than the plant-based biochars (PB-BC). However, the water soluble mineral levels were lower in the MW-BCs due to the dominant presence of less soluble minerals, such as CaCO3 and (Ca, Mg)3(PO4)2. The higher total minerals in MW-BCs accounted for the higher PZNC (5.47-9.95) than in PB-BCs (1.91-8.18), though the PZNCs of the PB-BCs increased more than that of the MW-BCs as the production temperature rose. The minerals had influence on the zeta potentials via affecting the negative charges of biochars and the ionic strength of solution. The organic functional groups in PB-BCs such as -COOH and -OH had a greater effect on the CEC and AEC, while the minerals had a greater effect on that of MW-BCs. The measured CEC and AEC values had a strong positive correlation with the total amount of soluble cations and anions, respectively. Results indicated that biochar surface charges depend not only on the organic functional groups, but also on the minerals present and to some extent, minerals have more influences on the surface electrochemistry and ion exchange properties of biochar.
KW - Anion exchange capacity
KW - Biochar
KW - Cation exchange capacity
KW - Mineral components
KW - Point of zero net charge
KW - Zeta potential
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U2 - 10.1016/j.chemosphere.2015.04.053
DO - 10.1016/j.chemosphere.2015.04.053
M3 - Article
C2 - 25974107
AN - SCOPUS:84983134540
VL - 136
SP - 133
EP - 139
JO - Chemosphere
JF - Chemosphere
SN - 0045-6535
ER -