Adsorption of Cu (II), Pb (II) and Cr (VI) from aqueous solutions using black wattle tannin-immobilized nanocellulose.
Adsorption of Cu (II), Pb (II) and Cr (VI) from aqueous solutions using black wattle tannin-immobilized nanocellulose.
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DOI：
10.1016/j.jhazmat.2017.06.005
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发表时间：
2017-10
影响因子：
13.6
通讯作者：
Qinghua Xu;Yulu Wang;Liqiang Jin;Yu Wang;M. Qin
中科院分区：
文献类型：
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作者：
Qinghua Xu;Yulu Wang;Liqiang Jin;Yu Wang;M. Qin
制备了一种新型的黑荆树单宁/纳米纤维素纳米复合材料，并将其应用于吸附去除水溶液中的重金属离子。首先，用高碘酸钠氧化纳米纤维素，得到双醛纳米纤维素(DANC)。然后将BW单宁共价固定在DANC上，DANC同时作为基质和交联剂，得到单宁-纳米纤维素(TNCC)复合材料。用FTIR、AFM和TG对所制备的纳米复合材料进行了表征。FeCl3与TNCC的显色反应和FT-IR分析证实了固定化的成功。AFM图像显示，TNCC为椭圆形颗粒，长度在100-400 nm之间。Zeta电位测量表明，在pH为1-12的范围内，TNCC为负电荷。与原单宁相比，纳米纤维素的加入使TNCC的热稳定性略有提高。在pH=2时，TNCC对铬(VI)的吸附效率最高，在pH=6时，对铜(II)和铅(II)的吸附效率最高。这三种金属离子的吸附符合准二级动力学，表明为化学吸附性质。吸附等温线均符合SIPS模型，计算出的最大吸附容量分别为104.592 mg/−、53.371 mg/−和51.846 mg/g−。
A novel nanocomposite based on black wattle (BW) tannin and nanocellulose was prepared and applied in heavy metal ions adsorptive removal from aqueous solutions. Firstly, nanocrystalline cellulose was oxidized by sodium periodate to get dialdehyde nanocellulose (DANC). BW tannin was then covalently immobilized onto DANC, which was used as both the matrix and crosslinker, to obtain tannin-nanocellulose (TNCC) composite. The resulting nanocomposite was characterized using FTIR, AFM, and TG. The successful immobilization was confirmed by the chromogenic reaction between FeCl3and TNCC and FT-IR analysis. AFM images revealed that TNCC was ellipsoidal particles with lengths ranging from 100–400 nm. Zeta potential measurement showed that TNCC was negative charged at a pH range from 1–12. Compared to the original tannin, the thermal stability of TNCC was slightly increased by the addition of nanocellulose. TNCC demonstrated the maximum adsorption efficiency at pH 2 for Cr(VI) and pH 6 for Cu(II) and Pb(II), respectively. The adsorption for these three metal ions followed pseudo second-order kinetics, indicating the chemisorption nature. The adsorption isotherms all fitted well with the Sips model, and the calculated maximum adsorption capacities were 51.846 mg g−1, 53.371 mg g−1and 104.592 mg g−1for Cu(II), Pb(II) and Cr (VI), respectively.