School of Water and Environment, Chang'an University, Xi'an 710054, China E-mail:
Water Sci Technol. 2021 Feb;83(3):678-688. doi: 10.2166/wst.2021.007.
Chitosan (CS) was modified with ferric chloride hexahydrate (FeCl·6HO) and sodium laurylsulfonate (SLS) to prepare the compound adsorbent CS-Fe-SLS. Taking Cr(VI) as the target pollutant, the influence of different factors (solution pH, adsorption time, initial adsorption concentration and coexisting ions) were investigated. The results showed that the optimal pH value was 3.0; the adsorption equilibrium was reached at 120 min, with both physical and chemical process being involved in the adsorption process; the maximum adsorption value was 131.91 mg/g, with the adsorption being both single-layer and multi-layer adsorption; Cl, NO and SO had little effect on adsorption, CO reduced it and Cu(II) increased it. The characterization results of scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction showed that CS-Fe-SLS and chitosan had different morphological characteristics: in contrast with chitosan, CS-Fe-SLS had a larger volume and more flakes on the surface. CS-Fe-SLS was significantly lower in crystallinity than chitosan, and was more irregular and amorphous in shape, and the experimental results showed that CS-Fe-SLS had better adsorption capacity for Cr(VI). The adsorption Cr(VI) was related to -NH and -OH on the material. Some Cr(VI) was reduced to Cr(III) during the adsorption process.
壳聚糖（CS）用六水合氯化铁（FeCl·6HO）和十二烷基硫酸钠（SLS）改性，制备了复合吸附剂 CS-Fe-SLS。以 Cr（VI）为目标污染物，考察了不同因素（溶液 pH 值、吸附时间、初始吸附浓度和共存离子）的影响。结果表明，最佳 pH 值为 3.0；吸附平衡在 120 min 内达到，吸附过程既有物理过程又有化学过程；最大吸附值为 131.91 mg/g，吸附既有单层吸附又有多层吸附；Cl、NO 和 SO 对吸附影响较小，CO 降低了吸附，Cu（II）增加了吸附。扫描电子显微镜、傅里叶变换红外光谱和 X 射线衍射的表征结果表明，CS-Fe-SLS 和壳聚糖具有不同的形态特征：与壳聚糖相比，CS-Fe-SLS 体积更大，表面有更多的薄片。CS-Fe-SLS 的结晶度明显低于壳聚糖，形状更不规则、无定形，实验结果表明 CS-Fe-SLS 对 Cr（VI）具有更好的吸附能力。吸附 Cr（VI）与材料上的-NH 和-OH 有关。在吸附过程中，部分 Cr（VI）被还原为 Cr（III）。
