TY - JOUR
T1 - Carbon transmission of CO2 activated nano-MgO carbon composites enhances phosphate immobilization
AU - Zhu, Xiangdong
AU - Liu, Yuchen
AU - Qian, Feng
AU - Shang, Hua
AU - Wei, Xinchao
AU - Zhang, Shicheng
AU - Chen, Jianmin
AU - Ren, Zhiyong Jason
N1 - Funding Information:
This research was funded by the National Key Research and Development Program of China (No. 2017YFC0212205), the National Key Technology Support Program (No. 2015BAD15B06), the National Natural Science Foundation of China (No. 21577025), and the International Postdoctoral Exchange Fellowship Program of China supported by Fudan University.
Publisher Copyright:
© 2018 The Royal Society of Chemistry.
PY - 2018
Y1 - 2018
N2 - Nano-MgO carbon composites (MCs) demonstrated great potential in phosphate immobilization to resolve phosphorus reuse and eutrophication problems, but the mechanisms of phosphate immobilization are still unclear. In this study, MCs were fabricated via CO2 activation of hydrochar materials, and the activation mechanisms were first investigated through analysis of pyrolysis gases and porosity. The results indicate that MgO particles (pyrolysis products of MgCl2) catalyzed the consumption of the carbon matrix but blocked the development of carbon matrix pores. Furthermore, phosphate immobilization by MCs increased with the increase of MgO loading content. More importantly, XPS and TEM-EDX profiles demonstrate that solution and surface precipitations regulated phosphate immobilization by MCs. Solution precipitation mainly contributed to a MgHPO4 precipitate, while in surface precipitation the carbon matrix served as a bridge for H2PO4- transmission to MgO particles to produce a Mg(H2PO4)2 precipitate. Also, with the decrease of carbon content, surface precipitation became dominant due to the shortened distance. This contributes to the improvement of phosphate immobilization by MCs, which was found to be even higher than pure MgO. Compared with N2 activated MC, CO2 activated MC showed much higher phosphate immobilization potential attributed to the surface precipitation reaction. The results of this study will guide the development of more efficient MC materials for phosphate recovery.
AB - Nano-MgO carbon composites (MCs) demonstrated great potential in phosphate immobilization to resolve phosphorus reuse and eutrophication problems, but the mechanisms of phosphate immobilization are still unclear. In this study, MCs were fabricated via CO2 activation of hydrochar materials, and the activation mechanisms were first investigated through analysis of pyrolysis gases and porosity. The results indicate that MgO particles (pyrolysis products of MgCl2) catalyzed the consumption of the carbon matrix but blocked the development of carbon matrix pores. Furthermore, phosphate immobilization by MCs increased with the increase of MgO loading content. More importantly, XPS and TEM-EDX profiles demonstrate that solution and surface precipitations regulated phosphate immobilization by MCs. Solution precipitation mainly contributed to a MgHPO4 precipitate, while in surface precipitation the carbon matrix served as a bridge for H2PO4- transmission to MgO particles to produce a Mg(H2PO4)2 precipitate. Also, with the decrease of carbon content, surface precipitation became dominant due to the shortened distance. This contributes to the improvement of phosphate immobilization by MCs, which was found to be even higher than pure MgO. Compared with N2 activated MC, CO2 activated MC showed much higher phosphate immobilization potential attributed to the surface precipitation reaction. The results of this study will guide the development of more efficient MC materials for phosphate recovery.
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U2 - 10.1039/c7ta10405g
DO - 10.1039/c7ta10405g
M3 - Article
AN - SCOPUS:85042398929
SN - 2050-7488
VL - 6
SP - 3705
EP - 3713
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 8
ER -