氧化法改性玉米秸秆及其对Cu(Ⅱ)的吸附综合实验  

Comprehensive Experiment of Oxidative Modification of Corn Straw and Its Adsorption of Cu(Ⅱ)

作　　者：王献玲[1,2] 王晓科[1] 吕建行 焦运红[1] 黄洁 韩冰[1] 秦江雷[1] WANG Xianling;WANG Xiaoke;LYU Jianxing;JIAO Yunhong;HUANG Jie;HAN Bing;QIN Jianglei(College of Chemistry and Materials Science,Hebei University,Baoding 071002,China;National Chemical Experimental Teaching Demonstration Center,Hebei University,Baoding 071002,China)

机构地区：[1]河北大学化学与材料科学学院,保定071002 [2]河北大学化学国家级实验教学示范中心,保定071002

出　　处：《实验科学与技术》2025年第2期68-77,共10页Experiment Science and Technology

基　　金：2024年河北大学大学生创新创业项目(DC2024161);河北省教改项目——流专业背景下材料化学专业人才培养模式创新的探索与实践(2025GJJG042)。

摘　　要：为促进学生掌握吸附法处理水中重金属污染的科研技术,寻找秸秆资源化新途径,设计了新型部分氧化法改性玉米秸秆(CS)及其对Cu(Ⅱ)的吸附综合实验。实验分别在O_(2)和N_(2)气氛,140~220℃下改性CS,以Cu(Ⅱ)为重金属目标物。通过氧化法改性的CS表面酸碱官能团含量的明显增加,有效提高了Cu(Ⅱ)的吸附量。结果表明:随改性温度升高,O_(2)气氛改性改性秸秆(以CS-气氛-温度命名)CS-O_(2)-T的总酸值、酚羟基、内酯基和总碱值的含量明显高于N_(2)改性CS-N_(2)-T。改性温度220℃时,CS-O_(2)-220对Cu(Ⅱ)的吸附量比CS-N_(2)-220提高34.5%,为原始CS的2.2倍。扫描电子显微镜(SEM)、比表面-孔径分布测试仪(BET)、傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)分析研究表明改性CS对Cu(Ⅱ)的吸附主要是以内酯基、酚羟基和芳香结构为主的官能团与Cu(Ⅱ)发生了络合作用和阳离子-π配位。实验帮学生构建了吸附法处理废水中重金属的理论知识,掌握了秸秆改性的实验技能,培养了学生的科研创新能力。Corn straw(CS)is a resourceful adsorption material that can be prepared easily at low cost and exhibits high specific surface area.However,in the adsorption of heavy metals it has limitations,such as unstable properties and small adsorption capacity.The adsorption capacity can be enhanced by modifying surface microstructure,such as increasing functional group content or enriching specific surface and pore structure.However,the toxic reagent,complicated process,long cycle,intense reaction conditions and high preparation cost have become the limitations of modification.New economic and sustainable technologies are urgently required to convert postharvest residues into value-added products with minimal impact on the environment.A low-temperature oxidation method has been suggested as an economic and effective strategy for turning biomass into environmental remediation materials.The CS were modified in O_(2)and N_(2)atmospheres from 140 to 220℃,respectively,and Cu(Ⅱ)was used as the heavy metal target.With the increase of modification temperature,the contents of total acid value,phenolic hydroxyl group,lactone group and total base value of CS(CS-O_(2)-T)modified at O_(2)atmosphere were significantly higher than those modified by N_(2)(CS-N_(2)-T).At the modified temperature of 220℃,the adsorption capacity of Cu(Ⅱ)by CS-O_(2)-220 is 34.5%higher than that by CS-N_(2)-220,which is 2.2 times of original CS.The results demonstrate that acid-base functional groups on the surface of CS were increased significantly,and the adsorption capacity of Cu(Ⅱ)was effectively increased after modified by oxidation.The results of SEM,BET,FTIR and XPS prove that the adsorption of Cu(Ⅱ)is mainly due to the complexation and cation-πcoordination of endoester group,phenolic hydroxyl group and aromatic structure by modified CS.This experiment helps students construct their theoretical knowledge such as the adsorption treatment of heavy metals in wastewater and master the experimental skills of straw modification,and it also cultiv

关 键 词：玉米秸秆 氧化改性 吸附 铜离子 官能团 

分 类 号：X52[环境科学与工程—环境工程] X71