Wang Li-Li, Ling Chen, Li Bang-Sen, Zhang Da-Shuai, Li Chen, Zhang Xiao-Peng, Shi Zai-Feng
College of Chemistry and Chemical Engineering, Key Laboratory of Water Pollution Treatment & Resource Reuse of Hainan Province, Hainan Normal University Haikou 571158 China
College of Biology and the Environment, Nanjing Forestry University Nanjing 210037 China.
RSC Adv. 2020 May 27;10(34):19943-19951. doi: 10.1039/d0ra02034f. eCollection 2020 May 26.
In this study, dendritic polyamine chitosan beads with and without 2-aminomethyl pyridine were facilely prepared and characterized. Compared to CN (without the pyridine function), more adsorption active sites, larger pores, higher nitrogen content, higher specific surface area, and higher strength could be obtained for CNP (with the pyridine function). CNP microspheres afforded a larger adsorption capacity than those obtained by CN for different pH values; further, the uptake amounts of Cu(ii) were 0.84 and 1.12 mmol g for CN and CNP beads, respectively, at pH 5. The CNP microspheres could scavenge Cu(ii) from highly acidic and salty solutions: the maximum simulated uptake amount of 1.93 mmol g at pH 5 could be achieved. Due to the strong bonding ability and weakly basic property of pyridine groups, the adsorption capacity of Cu(ii) at pH 1 was 0.75 mmol g in highly salty solutions, which was comparative to those obtained from the commercial pyridine chelating resin M4195 ( = 0.78 mmol g at pH 1). In addition, a distinct salt-promotion effect could be observed for CNP beads at both pH 5 and 1. Therefore, the prepared adsorbent CNP beads can have promising potential applications in the selective capturing of heavy metals in complex solutions with higher concentrations of H and inorganic salts, such as wastewaters from electroplating liquid and battery industries.
在本研究中，我们轻松制备并表征了含和不含2-氨甲基吡啶的树枝状多胺壳聚糖珠。与CN（无吡啶官能团）相比，含吡啶官能团的CNP具有更多的吸附活性位点、更大的孔径、更高的氮含量、更高的比表面积和更高的强度。对于不同的pH值，CNP微球的吸附容量比CN的更大；此外，在pH为5时，CN和CNP珠对Cu(ii)的摄取量分别为0.84和1.12 mmol/g。CNP微球能够从高酸性和高盐溶液中清除Cu(ii)：在pH为5时，最大模拟摄取量可达1.93 mmol/g。由于吡啶基团的强键合能力和弱碱性，在高盐溶液中，pH为1时CNP对Cu(ii)的吸附容量为0.75 mmol/g，这与商业吡啶螯合树脂M4195在pH为1时的吸附容量（0.78 mmol/g）相当。此外，在pH为5和1时，CNP珠均表现出明显的盐促进效应。因此，所制备的吸附剂CNP珠在选择性捕获高浓度H⁺和无机盐的复杂溶液中的重金属方面具有广阔的潜在应用前景，如电镀液和电池工业废水。
