Tan Jisuan, Song Yiheng, Huang Xiaohua, Zhou Li
College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China.
ACS Omega. 2018 Dec 13;3(12):17309-17318. doi: 10.1021/acsomega.8b02599. eCollection 2018 Dec 31.
The development of low-cost adsorbent with excellent adsorption property remains a big challenge. Herein, the functionalization of natural peach gum polysaccharide (PGP) with multiple amine groups for the removal of toxic Cr(VI) ions from water was studied. The obtained PGP-NH gel exhibited high-removal efficiency (>99.5%) toward Cr(VI) ions, especially with relatively low initial concentration of Cr(VI) ions (≤250 mg/L). The influences of pH, ionic strength, contact time, initial concentration, and temperature on the adsorption of Cr(VI) ions were systematically investigated. The PGP-NH gel showed rapid adsorption rate and could reach adsorption equilibrium within about 40 min. The Cr(VI) ion uptake process could be described by pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption capacity of PGP-NH gel could reach 188.32 mg/g. Thermodynamic investigation results indicated the spontaneous and exothermic characteristic of the uptake process. Moreover, the PGP-NH gel also exhibited favorable reusability, and 135.52 mg/g of adsorption capacity was retained even after being reused for five times. Considering its low cost and superior uptake property, the PGP-NH gel holds a great promise for employing as an adsorbent to treat Cr(VI) ion-containing wastewater.
开发具有优异吸附性能的低成本吸附剂仍然是一个巨大的挑战。在此，研究了用多个胺基对天然桃胶多糖（PGP）进行功能化处理以去除水中有毒Cr(VI)离子的情况。所制备的PGP-NH凝胶对Cr(VI)离子表现出高去除效率（>99.5%），特别是在Cr(VI)离子初始浓度相对较低（≤250 mg/L）时。系统研究了pH值、离子强度、接触时间、初始浓度和温度对Cr(VI)离子吸附的影响。PGP-NH凝胶显示出快速的吸附速率，并且在约40分钟内可达到吸附平衡。Cr(VI)离子的吸附过程可以用伪二级动力学和朗缪尔等温线模型来描述。PGP-NH凝胶的最大吸附容量可达188.32 mg/g。热力学研究结果表明吸附过程具有自发性和放热特性。此外，PGP-NH凝胶还表现出良好的可重复使用性，即使重复使用五次后仍保留135.52 mg/g的吸附容量。考虑到其低成本和优异的吸附性能，PGP-NH凝胶在用作处理含Cr(VI)离子废水的吸附剂方面具有很大的潜力。
