铁改性香蒲生物炭吸附去除水中刚果红的研究

Adsorptive Removal of Congo Red from Water by Iron-Modified Cattail Biochar

以湿地植物香蒲为原料,通过热解制备了生物炭(BC),采用水热法将Fe与BC复合,制备了具有良好磁性能的铁改性生物炭(Fe-BC)。采用SEM、BET、FT-IR、XRD、XPS和VSM等,分析了Fe-BC的结构形貌特性及磁性能,并研究了Fe-BC吸附去除水中典型有机染料刚果红(CR)的性能。结果表明:制备的Fe-BC具有良好的磁性,当CR浓度为100 mg/L、Fe-BC投加量为40 mg、溶液pH为3、吸附时间90 min、反应体系温度25℃时,CR的去除率可达99.6%;此外,Cu^(2+)、Zn^(2+)、Mn^(2+)金属阳离子可提高Fe-BC对CR的去除率;Fe-BC进行3次吸附-脱附后,Fe-BC对水中CR仍有良好吸附性能,表明磁性Fe-BC具有良好的循环稳定性;通过对动力学模型与热力学模型的拟合,表明Fe-BC对水中CR的吸附过程主要受化学吸附影响,且为自发不可逆的吸热反应。

Biochar(BC)was produced through the pyrolysis of cattail,a wetland plant,and iron-modified biochar(Fe-BC)with strong magnetic properties was then synthesized through hydrothermal compounding of Fe and BC.The structural morphology and magnetic properties of Fe-BC were characterized through numerous techniques such as SEM,BET,FT-IR,XRD,XPS,and VSM.Its potential for adsorbing and removing Congo(CR),a common waterborne organic dye,was evaluated.It was revealed that the Fe-BC exhibited highly effective magnetic properties,with a CR removal rate of 99.6%achieved at a CR concentration of 100 mg/L,Fe-BC dosage of 40 mg,solution pH of 3,an adsorption time of 90 minutes,and an adsorption temperature of 25℃.Notably,the removal of CR by Fe-BC can be strengthened by Cu^(2+),Zn^(2+),and Mn^(2+)metal cations.Moreover,the Fe-BC exhibited very stable adsorption performance for CR after three cycles of adsorption and desorption,demonstrating very good cyclic stability of the magnetic Fe-BC.The fitting of the kinetic model to the thermodynamic model suggested that the adsorption of CR onto Fe-BC is predominantly affected by chemisorption and characterized as a spontaneous,irreversible endothermic reaction.