Zhu Danchen, Yang Haiping, Chen Xu, Chen Wei, Cai Ning, Chen Yingquan, Zhang Shihong, Chen Hanping
State Key Laboratory of Coal Combustion, School of Power and Energy Engineering, Huazhong University of Science and Technology, 430074, Wuhan, China.
State Key Laboratory of Coal Combustion, School of Power and Energy Engineering, Huazhong University of Science and Technology, 430074, Wuhan, China.
Chemosphere. 2021 Jul;274:129904. doi: 10.1016/j.chemosphere.2021.129904. Epub 2021 Feb 9.
Nano-MgO biochar composites (nMBCs) have been considered as potential adsorbents for phosphate removal from aqueous solution. It is an effective strategy to improve P removal efficiency that adjustment of the size, distribution and crystallinity of MgO particles embedded into the carbon matrix. Herein, we prepared a highly efficient phosphate adsorbent by co-pyrolysis of lotus seedpod and magnesium citrate and studied its adsorption mechanisms. Results showed that the uniformly dispersed MgO nanoparticle was formed on the surface of nMBCs with the temperature increasing, with the particles size ranging from 3 to 10 nm. Furthermore, high temperature promoted the formation of a large amount of reactive lattice oxygen, which was demonstrated to be the main active adsorption site, thus the phosphate immobilization capacity of nMBCs was greatly improved with the pyrolysis temperature increasing from 450 °C to 750 °C. Besides, some stable CO bonds were formed due to the catalysis of Mg, which could bond to HPO/HPO by hydrogen bond, enhancing the adsorption performance. The isotherm adsorption experiment showed that MBC-750 achieved an excellent phosphorus adsorption amount of 452.752 mg-P/g. The effectiveness of nMBCs is enhanced and a method for producing an effective nanocomposite adsorbent material for removing phosphate from wastewater is provided.
纳米氧化镁生物炭复合材料（nMBCs）被认为是从水溶液中去除磷酸盐的潜在吸附剂。调节嵌入碳基质中的氧化镁颗粒的尺寸、分布和结晶度是提高磷去除效率的有效策略。在此，我们通过莲子荚与柠檬酸镁的共热解制备了一种高效的磷酸盐吸附剂，并研究了其吸附机制。结果表明，随着温度升高，nMBCs表面形成了均匀分散的氧化镁纳米颗粒，粒径范围为3至10纳米。此外，高温促进了大量活性晶格氧的形成，这被证明是主要的活性吸附位点，因此随着热解温度从450℃升高到750℃，nMBCs的磷酸盐固定能力大大提高。此外，由于镁的催化作用形成了一些稳定的C-O键，其可通过氢键与HPO₄²⁻/H₂PO₄⁻结合，增强了吸附性能。等温吸附实验表明，MBC-750实现了452.752 mg-P/g的优异磷吸附量。提高了nMBCs的有效性，并提供了一种生产用于去除废水中磷酸盐的有效纳米复合吸附材料的方法。
