中文关键词纳米材料载镧水热生物炭磁性 英文关键词nano-materialsLa-loadedhydrothermalbiocharmagnetism

作者	单位	E-mail
宋小宝	南京理工大学化工学院, 南京 210094 江苏省农业科学院农业资源与环境研究所, 南京 210014	15850517568@163.com
何世颖	江苏省农业科学院农业资源与环境研究所, 南京 210014
冯彦房	江苏省农业科学院农业资源与环境研究所, 南京 210014
花昀	江苏省农业科学院农业资源与环境研究所, 南京 210014
唐婉莹	南京理工大学化工学院, 南京 210094	1269920308@qq.com
朱秋蓉	南京理工大学化工学院, 南京 210094 江苏省农业科学院农业资源与环境研究所, 南京 210014
薛利红	江苏省农业科学院农业资源与环境研究所, 南京 210014
杨林章	江苏省农业科学院农业资源与环境研究所, 南京 210014

中文摘要 将小麦秸秆在水热条件下（220℃）炭化2 h得到水热生物炭（HTC），以HTC为载体，通过一步共沉淀法制备了一种吸附容量高、易于磁分离回收的载镧磁性水热生物炭复合材料（La-MHTC）.通过等温线和动力学等吸附实验方法，研究了该材料对磷酸根的吸附特性，考察了载镧量、初始pH和共存离子等因素对磷酸根吸附过程的影响.结果表明La³⁺：Fe³⁺为2：1时，材料（2-La-MHTC）具有良好的吸附磷酸根的能力；在吸附剂投加量为0.1 g·L^-1，pH为7时，对磷酸盐吸附量达到100.25 mg·g^-1；吸附符合Langmuir等温模型，吸附动力学过程遵循准二级动力学，并且吸附不受其它离子的影响（在Cl^-、NO₃^-和SO₄^2-等共存离子体系磷酸盐去除率达到98%），在较广的pH（3~10）范围都具有良好的吸磷能力.吸附的磷酸根可用NaOH溶液解吸，5次吸附-脱附循环实验中磷酸盐去除率均能达到90%以上，脱附效率为65%左右，说明该吸附剂具有良好的脱附和重复利用能力.应用其处理实际含磷污水，可将磷酸盐浓度从0.87 mg·L^-1降低到0.05 mg·L^-1.吸附机制主要为静电吸附作用和La（OH）₃与磷酸盐通过配体交换形成内层络合物. 英文摘要 Lanthanum (La)-based materials have shown great potential for phosphate removal owing to the strong affinity between La and phosphate. In this study, magnetic hydrothermal biochar immobilized La(OH)₃ (La-MHTC) were prepared and used as phosphate adsorbents. Hydrochar was produced by the hydrothermal carbonization process (220℃, 2 h). Magnetic La-MHTC with different La-to-Fe mass ratios were synthesized by the co-precipitation method. Subsequently, La-MHTC was applied to remove phosphate from wastewater. Results indicate that La-MHTC (with a La-to-Fe mass ratio of 2:1) exhibited excellent magnetic properties for easy recovery and high phosphate adsorption capacity up to 100.25 mg·g^-1. Effective phosphate removal was obtained over a wide pH range of 3-10. The absorption isotherm and kinetics were better fitted by the Langmuir model and the pseudo second-order model, respectively, which showed a fast adsorption rate and exhibited superior La utilization efficiency. The La-MHTC has strong selectivity for phosphate in the presence of coexisting ions (Cl^-, NO₃^-, and SO₄^2-). The adsorption-desorption experiment suggested its excellent stability and cyclic utilization. In addition, La-MHTC was applied to treat real domestic wastewater, efficiently reducing the phosphate concentration (from 0.87 mg·L^-1 to 0.05 mg·L^-1). Electrostatic attraction and inner-sphere complexation between La(OH)₃ and P via ligand exchange were the main mechanisms of phosphate adsorption by La-MHTC.

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