三种改性玉米秸秆对亚甲基蓝吸附性能的影响

Adsorption Performance of Methylene Blue by Three Kinds of Modified Corn Straw

采用正交试验法,确定了微波氯化锌改性玉米秸秆、NaOH改性玉米秸秆和纤维素酶改性玉米秸秆的最佳改性条件;通过扫描电子显微镜和傅立叶红外光谱仪对改性前后的结构、组成进行了测定;试验对比了不同改性秸秆投加量、溶液pH对亚甲基蓝吸附速率的影响。结果表明:最佳改性条件下的3种改性玉米秸秆,对亚甲基蓝溶液吸附1 h,吸附率可分别达到84.67%、98.76%和99.63%;3种改性玉米秸秆皆暴露出更多内部结构,表面变得粗糙蓬松;在一定范围内,随着投加量和pH增大,吸附速率提高。3种改性玉米秸秆的吸附过程都符合Langmuir等温吸附模型和拟二级动力学模型,是单层吸附且吸附速率由化学吸附主要控制。

The optimum modification conditions of the three kinds of modified corn straw, micro- wave-zinc chloride, NaOH and cellulose enzyme modified corn straw, were determined by orthogonal experiment method. The results showed that removal rate of the three optimum modification condi- tions of modified corn straw reached 84. 67%, 98.76% and 99. 63%, respectively, when adsorption time of methylene blue was 1 h. The modified corn straw and the original corn straw were character- ized by scanning electron microscope and Fourier transform infrared spectrometer on structure and composition. The results showed that the three kinds of modified corn straw exposed more internal structure, the surface of which became rough and shaggy. The effects of different modification addi- tive amounts of corn straw and solution pH on methylene blue adsorption rate were experimented on and compared. The results showed that adsorption rate was improved as additive quantity and pH in- creased within a certain range. The three kinds of modified corn straw matched the Langmuir iso- therm and pseudo-second-order kinetic model, which was monolayer adsorption and the adsorption rate was mainly controlled by chemical adsorption.