金属改性玉米秸秆生物质炭吸附恩诺沙星的机理研究

Mechanism of adsorption of enrofloxacin by metal modified corn stalk biochar

目的提高传统玉米秸秆生物质炭对抗生素的吸附能力,研究生物质炭对恩诺沙星的吸附机理。方法利用FeCl3和ZnCl2对玉米秸秆生物质炭进行铁改性和锌改性,运用SEM、FTIR、XRD等分析方法研究改性前后生物质炭的性质和结构,并进行吸附试验。结果铁改性和锌化生物质炭表面含氧官能团数量增加,微孔所占体积增大,比表面积分别增大了9.7和8.1倍;XRD图谱显示改性后生物质炭结晶性降低,稳定性下降。铁改性和锌化后的生物质炭,对恩诺沙星的最大吸附量分别提高了21.30%和10.81%,准二级动力学方程跟Langmuir方程能很好的描述3种炭的吸附过程,吸附热力学分析显示3种炭对恩诺沙星的吸附是一个自发、吸热、无序的过程。结论经过铁改性和锌改性后,能够增大生物质炭的比表面积及孔隙结构,使得生物质炭能够提供更多的吸附位点,从而增强其对恩诺沙星的吸附能力。

Objective Improve the adsorption capacity of traditional biochar on antibiotics,and the adsorption mechanism of postgraduate charcoal on enrofloxacin.Methods Magnetization and zincation modification of corn stalkbiochar with FeCl3 and ZnCl2,SEM,FTIR,XRD and other analytical methods were used to study the properties and structures of biochar before and after modification,and the adsorption test was conducted.Results After magnetization and zincation,the number of oxygen-containing functional groups on the surface of iron modified and zincated biomass carbon increased,the volume of micropores increased,and the specific surface area increased by 9.7 and 8.1 times respectively.The XRD pattern showed that the crystallinity of the modified biomass carbon and the stability decreased.The maximum adsorption capacity of enrofloxacin was improved by 21.31%and 10.81%,respectively.The quasi-secondary kinetic equation and the Langmuir equation can describe the adsorption process of three kinds of carbon well.Adsorption thermodynamic analysis showed that the adsorption of enrofloxacin by three carbons was a spontaneous,endothermic,and disordered process.Conclusion After magnetization and zincation modification,it can increase the specific surface area and pore structure of biomass carbon,so that biochar can provide more adsorption sites,thereby enhancing its adsorption capacity for enrofloxacin.