1 Biochar Engineering Technology Research Center of Guangdong Province, School of Environmental and Chemical Engineering, Foshan University, Foshan, China. Electronic address: hailong.wang@fosu.edu.cn.
2 School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
3 University of Wuppertal, School of Architecture and Civil Engineering, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; Department of Environment, Energy & Geoinformatics, Sejong University, Seoul 05006, Republic of Korea.