Lyu Peng, Li Lianfang, Huang Jinli, Ye Jing, Zhu Changxiong, Xie Jinni, Wang Zihan, Kang Mengqi, Yan Ao
Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Key Laboratory of Agro-Environment, Ministry of Agriculture and Rural Affairs, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Key Laboratory of Agro-Environment, Ministry of Agriculture and Rural Affairs, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Bioresour Technol. 2023 Nov;388:129756. doi: 10.1016/j.biortech.2023.129756. Epub 2023 Sep 9.
The impact of multiple preparation protocols on properties and performance of modified biochar remains unclear. This study prepared layered double hydroxide (LDH)-based magnetic biochars (LMBCs) with different LDH loading rates (LLR), pyrolysis temperatures, and biomass sources to explore their performance-characterization relationships toward As(III) and Cd(II). Higher LLR and pyrolysis temperature enhanced LMBCs᾿ adsorption capacities by increasing specific surface area (SSA) and metal/O-containing groups. Hence, LMBC produced at 2:1 LLR (LDH: magnetic biochar) and 800 ℃ pyrolysis exhibited maximum adsorption over 2 times that of LMBC with 0.5:1 LLR and 400 ℃ pyrolysis. Bamboo-sourced LMBC demonstrated superior adsorption than sewage sludge and garlic-sourced LMBCs due to its increased SSA, enabling a higher loading of nano-LDH. Adsorption of As(III) and Cd(II) onto LMBCs was governed by metal-mineral and metal-containing group through co-precipitation and complexation. This study provides a reference for adjusting the preparation protocols to improve sorption performance of modified biochar toward multiple heavy metals.
多种制备方案对改性生物炭的性质和性能的影响尚不清楚。本研究制备了具有不同层状双氢氧化物（LDH）负载率（LLR）、热解温度和生物质来源的基于LDH的磁性生物炭（LMBC），以探索它们对As(III)和Cd(II)的性能-表征关系。较高的LLR和热解温度通过增加比表面积（SSA）和含金属/氧基团来提高LMBC的吸附能力。因此，在2:1的LLR（LDH:磁性生物炭）和800℃热解条件下制备的LMBC的最大吸附量是在0.5:1的LLR和400℃热解条件下制备的LMBC的2倍以上。竹源LMBC由于其增加的SSA而表现出比污水污泥和蒜源LMBC更好的吸附性能，从而能够更高地负载纳米LDH。As(III)和Cd(II)在LMBC上的吸附通过共沉淀和络合作用受金属矿物和含金属基团的控制。本研究为调整制备方案以提高改性生物炭对多种重金属的吸附性能提供了参考。
