壳聚糖/磁性榴莲生物炭对亚甲基蓝的吸附研究

Adsorption of Methylene Blue by Chitosan/Magnetic Durian Biochar

该文以榴莲壳为原料,通过磁改性和壳聚糖改性,制备出了榴莲壳聚糖/磁性生物炭(CMDSB)。将制备的CMDSB用于对模拟染料废水中亚甲基蓝的吸附,研究CMDSB对亚甲基蓝的吸附效果和吸附机理。实验结果表明,CMDSB对160 mg/L的亚甲基蓝溶液在吸附时间30 min时,去除率可以达到96.96%。CMDSB对亚甲基蓝在pH为5~12的范围内均有非常好的吸附效果。Freundlich等温吸附方程结果较好(P<0.01),表明吸附主要是以多分子层吸附为主;吸附动力学符合二级动力学模型,说明吸附主要是以化学吸附为主。SEM、XRD、FT-IR和BET分析结果表明,铁成功负载到了生物炭上,并且经过壳聚糖改性之后,CMDSB表面的官能团种类有了明显的增多,为化学吸附提供了诸多的活性位点。CMDSB可多次循环利用,在循环使用5次之后,对亚甲基蓝的去除率仍有73.35%,是一种绿色环保的吸附材料。

Durian chitosan/magnetic biochar(CMDSB)was prepared from durian shell by magnetic modification and chitosan modification.The prepared CMDSB was used to adsorb methylene blue in simulated dye wastewater,and the adsorption effect and mechanism of CMDSB on methylene blue were studied.The experimental results show that the removal rate of160 mg/L methylene blue solution by CMDSB can reach 96.96%,when the adsorption time is 30 min.CMDSB has very good adsorption effect on methylene blue in the range of p H 5~12.The results of Freundlich isothermal adsorption equation were good(P<0.01),it shows that the adsorption is mainly multilayer adsorption;the adsorption kinetic conforms to the secondorder kinetic model,it shows that the adsorption is mainly chemical adsorption.SEM,XRD,FT-IR and BET analysis showed that iron was successfully loaded on biochar,and after chitosan modification,the types of functional groups on the surface of CMDSB increased significantly,providing many active sites for chemical adsorption.CMDSB can be recycled for many times,after five times of recycling,the removal rate of methylene blue is still 73.35%,it is a green and environmental friendly adsorption material.