Liu Shuli, Duan Zhengyang, He Changhua, Xu Xiaojun, Li Tianguo, Li Yuhuan, Li Xuan, Wang Yao, Xu Longqian
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology Kunming Yunnan 650500 China
College of Resources and Environment, Yunnan Agricultural University Kunming Yunnan 650201 China.
RSC Adv. 2018 Feb 20;8(15):8026-8038. doi: 10.1039/c7ra13545a. eCollection 2018 Feb 19.
Phosphate-modified baker's yeast (PMBY) was prepared, and used as a novel bio-sorbent for the adsorption of Pb from aqueous solution. The influencing factors, absorption isotherms, kinetics, and mechanism were investigated. The scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) characterization and elemental analysis of PMBY showed that phosphate groups were successfully grafted onto the surface of yeast. The kinetic studies suggested that the adsorption process followed a pseudo-second-order chemisorption. The adsorption process of Pb using PMBY was spontaneous and endothermic. Furthermore, the adsorption of Pb on PMBY can rapidly achieve adsorption equilibrium (in just 3 min), and the maximum adsorption capacity of Pb on PMBY was found to be 92 mg g at 30 °C, which was about 3 times that of the pristine baker's yeast. The suggested mechanism for Pb adsorption on PMBY was based upon ion-exchange, electrostatic interaction and chelation between the phosphate groups and Pb. However, compared with the pristine baker's yeast, the higher capacity and rapid adsorption of PMBY for Pb was mainly due to the chelation and electrostatic interactions between the phosphate groups and Pb. In addition, the regeneration experiments indicated that the PMBY was easily recovered through desorption in 0.01 M HCl, and that PMBY still exhibited 90.77% of the original adsorption capacity for Pb after five regeneration cycles. These results showed the excellent regeneration capability of PMBY for Pb adsorption. PMBY has shown significant potential for the removal of heavy metals from aqueous solution due to its rapid adsorption, high-capacity and facile preparation.
制备了磷酸盐改性面包酵母（PMBY），并将其用作从水溶液中吸附铅的新型生物吸附剂。研究了影响因素、吸附等温线、动力学和吸附机理。对PMBY的扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）表征及元素分析表明，磷酸基团成功接枝到酵母表面。动力学研究表明，吸附过程遵循准二级化学吸附。用PMBY吸附铅的过程是自发的且吸热的。此外，铅在PMBY上的吸附能迅速达到吸附平衡（仅需3分钟），在30℃时，铅在PMBY上的最大吸附容量为92 mg/g，约为原始面包酵母的3倍。推测PMBY对铅的吸附机理基于磷酸基团与铅之间的离子交换、静电相互作用和螯合作用。然而，与原始面包酵母相比，PMBY对铅的高吸附容量和快速吸附主要归因于磷酸基团与铅之间的螯合和静电相互作用。此外，再生实验表明，PMBY在0.01 M HCl中通过解吸很容易回收，并且在五个再生循环后，PMBY对铅的吸附容量仍为原始吸附容量的90.77%。这些结果表明PMBY对铅吸附具有优异的再生能力。由于其快速吸附、高吸附容量和制备简便，PMBY在从水溶液中去除重金属方面显示出巨大潜力。
