AA/SiO_(2)/CTS复合材料制备及其吸附铬离子研究

Preparation of AA/SiO_(2)/CTS composite and its adsorption of chromium ions

通过浸渍法分别用丙烯酸(AA)和纳米二氧化硅(SiO_(2))改性壳聚糖(CTS),制备AA/SiO_(2)/CTS复合材料。通过红外光谱表征了复合材料的结构,并以复合材料为吸附剂吸附铬离子,研究了复合材料吸附铬离子的吸附性能。结果表明:当吸附剂用量为2.0g,pH为6左右,铬离子浓度为20mg/L,温度为25℃,吸附70min时,吸附效果最好,改性后的复合吸附剂AA/SiO_(2)/CTS的吸附率最高可达96%,明显高于未改性CTS的85%和AA/CTS的92%。吸附热力学和动力学研究表明,Freundlich等温模型和拟二级动力学模型更加符合吸附过程。

Chitosan(CTS)was modified with acrylic acid(AA)and nano silica(SiO_(2))by impregnation to prepare AA/SiO_(2)/CTS composite.The structure of the composite was characterized by infrared spectroscopy,and its adsorption performance for chromium ion was studied by using the composite material as adsorbent.The results showed that the adsorption effect was the best when the dosage of adsorbent was 2.0g,the pH value was about 6,the concentration of chromium ion was 20mg/L,the temperature was 25℃,and the adsorption time was 70min.The adsorption rate of modified composite adsorbent AA/SiO_(2)/CTS could reach 96%,which was significantly higher than 85%of unmodified CTS and 92%of AA/CTS.The adsorption thermodynamics and kinetics studies revealed that Freundlich isothermal model and pseudo second-order kinetic model were more consistent with the adsorption process.