Potentials of emergent plant residue derived biochar to be alternative carbon-based phosphorus fertilizer by Fe(II)/Fe(III) magnetic modification
Hongjuan Xin,
Jiao Yang,
Yuanyuan Lu,
Hekang Xiao,
Haitao Wang,
Kamel M. Eltohamy,
Xueqi Zhu,
Chunlong Liu,
Yunying Fang,
Ye Ye,
Xinqiang Liang
Affiliations
Hongjuan Xin
Key Laboratory of Watershed Non-Point Source Pollution Control and Water Eco-Security of Ministry of Water Resources, College of Environmental and Resources Sciences, Zhejiang University
Jiao Yang
Key Laboratory of Watershed Non-Point Source Pollution Control and Water Eco-Security of Ministry of Water Resources, College of Environmental and Resources Sciences, Zhejiang University
Yuanyuan Lu
Key Laboratory of Watershed Non-Point Source Pollution Control and Water Eco-Security of Ministry of Water Resources, College of Environmental and Resources Sciences, Zhejiang University
Hekang Xiao
Key Laboratory of Watershed Non-Point Source Pollution Control and Water Eco-Security of Ministry of Water Resources, College of Environmental and Resources Sciences, Zhejiang University
Haitao Wang
Key Laboratory of Watershed Non-Point Source Pollution Control and Water Eco-Security of Ministry of Water Resources, College of Environmental and Resources Sciences, Zhejiang University
Kamel M. Eltohamy
Key Laboratory of Watershed Non-Point Source Pollution Control and Water Eco-Security of Ministry of Water Resources, College of Environmental and Resources Sciences, Zhejiang University
Xueqi Zhu
Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences
Chunlong Liu
Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences
Yunying Fang
Australian Rivers Institute, School of Environment and Science, Griffith University
Ye Ye
Sino-Japan Friendship Centre for Environmental Protection
Xinqiang Liang
Key Laboratory of Watershed Non-Point Source Pollution Control and Water Eco-Security of Ministry of Water Resources, College of Environmental and Resources Sciences, Zhejiang University
Abstract Emergent plants have been remarkably effective in reducing phosphorus (P) discharge from ecological ditches; however, the treatment and recycling of these residues is a great challenge. In this study, magnetic biochars (MBs, i.e., MB-A, MB-C, and MB-T) were fabricated from three emergent plant residues (Acorus calamus L., Canna indica L., and Thalia dealbata Fraser, respectively) and modified with Fe(II)/Fe(III). Scanning electron microscopy-energy dispersive spectroscopy and X-ray diffraction spectra confirmed the successful loading of Fe3O4 and FeO(OH) onto the surfaces of the MBs. Batch adsorption experiments showed that MBs exhibited a higher P adsorption capacity than that of the raw biochars. Within the range of 0.8–43.0 mg L−1 in solution, the adsorption capacities of P by MB-A, MB-C, and MB-T were 304.6–5658.8, 314.9–6845.6, and 292.8–5590.0 mg kg−1, with adsorption efficiencies of 95.2–32.9%, 98.4–39.8%, and 91.5–32.5%, respectively. The primary mechanisms that caused P to adsorb onto the MBs were inner-sphere complexation and electrostatic attraction. Low pH conditions were more beneficial for the P adsorption of the MBs, while co-existing anions had a negative impact with the following order: HCO3 − > SO4 2− > Cl−≈NO3 −. The P-31 nuclear magnetic resonance results further demonstrated that the main adsorbed P species on the MBs was orthophosphate, followed by orthophosphate monoesters and DNA. Overall, MBs offer a resource utilization strategy for emergent plant residues and P-laden MBs are promising alternative P fertilizers. Graphical Abstract