NaOH改性玉米秸秆对石油类污染物的吸附研究

Optimization of NaOH Modified Corn Stalk and Its Adsorption of Petroleum Pollutants

采用正交试验设计,对农业废弃物玉米秸秆进行NaOH化学改性,制得吸附剂,并分别考察其对原油、0#柴油、97#汽油的吸附性能。结果表明,在温度为80℃、NaOH质量分数为1%、固液比为1∶20、时间为12 h的条件下,玉米秸秆经NaOH改性后对3种油类的最大吸附量分别比改性前提高了22.62%、37.57%和38.50%。对改性前后秸秆主要组成成分和FTIR的分析发现,改性后秸秆中木质素和半纤维素的相对含量减少了,纤维素的相对含量增加了;主要存在于木质素和半纤维素中的羧基在改性后显著减少,代表纤维素的醇峰峰值却得到了提升,与改性前后组分变化一致。通过对比分析改性前后玉米秸秆的SEM图像表明,NaOH破坏了玉米秸秆的原始表面结构,使其变得疏松多孔,从而更加有利于秸秆对油的吸附。

Orthogonal experimental design was used to study the modification of corn stalk by NaOH for producing adsorbent of petroleum pollutants. The modified corn stalk was used to adsorb crude oil, 0# diesel and 97# gasoline respectively, and results showed the maximum adsorption capacity of the three oils increased by 22.62%, 37.57% and 38.50% when compared to untreated corn stalk. After modified, the content of lignin and hemicellulose in corn stalk was decreased, while cellulose increased relatively. Fourier transform infrared spectroscopy showed that carboxyl of modified corn stalk, major existed in lignin and hemicellulose, was reduced; alcohol hydroxyl, represented cellulose, was improved. These results were consistent with the changes in the components of the modified corn stalk. SEM image of modified corn stalk indicated that NaOH destroyed the original surface structure of corn stalk and made more holes, thus led it more conducive to adsorption of oils.