磁性阳离子型壳聚糖絮凝剂去除Cr (Ⅵ)

以二氧化硅和硅烷偶联剂（KH-570）包裹的磁性Fe₃O₄作为磁芯，壳聚糖（CS）、丙烯酰胺（AM）和丙烯酰氧乙基三甲基氯化铵（DAC）作为接枝单体，通过低压紫外光引发合成新型磁性壳聚糖絮凝剂（FSCAD），研究该材料对Cr （Ⅵ）的去除性能.采用傅立叶变换红外、热重分析、X射线衍射图谱和振动样品磁强计对絮凝剂进行表征，显示材料成功制备并具有良好的磁响应性.系统探究了pH值、絮凝剂投加量、反应时间、干扰离子对絮凝性能的影响并拟合絮凝剂絮动力学模型.结果表明，絮凝剂絮凝动力学符合拟二级动力学方程，在投加量为900mg/L、pH值为3、反应时间为60min时FSCAD对低浓度Cr （Ⅵ）废水的去除效果可达到90.48%.

Synthesis of magnetic cationic chitosan flocculant by low-pressure UV light for the removal of Cr(Ⅵ)

A new magnetic chitosan flocculant FSCAD was synthesized by using magnetic Fe₃O₄ coated with silica and silane coupling agent (KH-570) as magnetic core, chitosan, acrylamide and acryloyloxyethyl trimethylammonium chloride as graft monomers and low-pressure ultraviolet light as initiator, the Cr(Ⅵ) removal properties of the material were studied. The flocculants were characterized by fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffractometer and vibration sample magnetometer, showing the materials were successfully prepared and have good magnetic response. The effects of pH, dosage, reaction time and interference ions on flocculation properties were explored and fitted to the flocculation dynamics model. The flocculation kinetics accorded with the pseudo second order kinetic equation and the removal effect of FSCAD on low concentration Cr(Ⅵ) wastewater reached 90.48% at the added amount of 900mg/L, pH of 3 and the reaction time of 60min.