School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China E-mail:
Water Sci Technol. 2017 Apr;2017(1):16-26. doi: 10.2166/wst.2018.064.
In this study, we provide the first documented removal of humic acid (HA) from aqueous solution using polyacrylamide/chitosan (PAAm/CS) semi-IPN hydrogel. The prepared semi-IPN hydrogel was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The factors effecting HA adsorption performance were individually tested, including initial pH, ionic strength, contact time, initial HA concentration, and temperature. The results indicated that semi-IPN hydrogel was successfully fabricated and can be applied in a wide pH range, from 3 to 9. Low ionic strength effectively enhanced the adsorption capacity. As the ionic strength increased, this enhancement was less obvious but still positive. The adsorption kinetics were fitted to a pseudo-first-order kinetic model, and the adsorption isotherm was described using the Sips isotherm model. The HA adsorption capacity increased with increasing temperature. The maximum adsorption capacity has the potential to attain 166.30 mg g, based on the Sips isotherm at 25 °C. Experiments demonstrated that the HA adsorption process can be primarily attributed to electrostatic interactions, and hydrogen bonding was also involved. Facile synthesis and good adsorptive performance indicate that semi-IPN hydrogel can be used for removing HA from water.
在这项研究中，我们首次使用聚丙烯酰胺/壳聚糖（PAAm/CS）半互穿网络水凝胶从水溶液中去除腐殖酸（HA）。通过扫描电子显微镜（SEM）和傅里叶变换红外光谱（FT-IR）对制备的半互穿网络水凝胶进行了表征。分别测试了影响 HA 吸附性能的因素，包括初始 pH 值、离子强度、接触时间、初始 HA 浓度和温度。结果表明，成功制备了半互穿网络水凝胶，可在较宽的 pH 值范围内（3-9）使用。低离子强度有效地提高了吸附容量。随着离子强度的增加，这种增强作用不那么明显，但仍然是积极的。吸附动力学拟合伪一级动力学模型，吸附等温线用 Sips 等温线模型描述。HA 的吸附容量随温度的升高而增加。根据 25°C 下的 Sips 等温线，最大吸附容量有达到 166.30mg/g 的潜力。实验表明，HA 的吸附过程主要归因于静电相互作用，氢键也参与其中。简单的合成和良好的吸附性能表明，半互穿网络水凝胶可用于从水中去除 HA。
