Abstract：
Phosphorus (P) scarcity and eutrophication have triggered the development of new materials for P recovery. In this work, a novel magnetic calcium-rich biochar nanocomposite (MCRB) was prepared through co-precipitation of crab shell derived biochar, Fe2+ and Fe3+. Characteristics of the material demonstrated that the MCRB was rich in calcite and that the Fe3O4 NPs with a diameter range of 18-22 nanometers were uniformly adhered on the biochar surface by strong ether linking (C-O-Fe). Batch tests demonstrated that the removal of P was pH dependent with an optimal pH of 3-7. The MCRB exhibited a superior P removal performance, with a maximum removal capacity of 105.6 mg g-1, which was even higher than the majority lanthanum containing compounds. Study of the removal mechanisms revealed that the P removal by MCRB involved the formation of hydroxyapatite (HAP-Ca5(PO4)3OH), electrostatic attraction and ligand exchange. The recyclability test demonstrated that a certain level (approximately 60%) was still maintained even after the six adsorption-desorption process, suggesting that MCRB is a promising material for P removal from wastewater.
摘要：
磷（P）的匮乏和富营养化引发了用于P回收的新材料的开发。在这项工作中,一种新型的磁性富钙生物炭纳米复合材料（MCRB）通过共沉淀蟹壳衍生的生物炭，Fe2+和Fe3+。材料的特征表明，MCRB富含方解石，直径为18-22纳米的Fe3O4NPs通过强醚连接（C-O-Fe）均匀地粘附在生物炭表面。批量测试表明，P的去除取决于pH，最佳pH为3-7。MCRB表现出优异的P去除性能，最大去除能力为105.6mgg-1，甚至高于大多数含镧化合物。对去除机理的研究表明，MCRB去除P涉及羟基磷灰石（HAP-Ca5（PO4）3OH）的形成，静电吸引和配体交换。可回收性测试表明，即使在六个吸附-解吸过程之后，仍保持一定水平（约60％）。表明MCRB是一种很有前途的去除废水中磷的材料。
