蚕丝改性工艺优化及其对Zn^(2+)的吸附性能研究

The study on optimization of silk modification process and the adsorption ability of modified silk on Zn^(2+)

以有效氯质量分数、改性时间、浴比(NaClO溶液体积与蚕丝质量的比值)为3个显著影响因素,以蚕丝回收率为响应值,采用响应面分析法对蚕丝的改性工艺条件进行最优化研究,并对改性蚕丝对Zn^(2+)的吸附性能进行分析。结果表明,蚕丝回收率关于3个因素的二次回归方程显著性高(P=0.000 4、R2=0.961 6),且失拟项不显著(P=0.900 2),与实际实验拟合良好。经最优化分析,得到最佳改性工艺为有效氯质量分数2.00%、改性时间10h、浴比为600mL/g,此时改性蚕丝的回收率为58.30%。在pH为6.5、温度为30℃、吸附时间为420min、振荡速度为150r/min、固液比(改性蚕丝质量与含Zn^(2+)模拟废水体积的比值)为1g/L时,改性蚕丝对Zn^(2+)的吸附在开始阶段非常迅速,240 min时达到平衡,吸附动力学符合Lagergren准二级动力学方程(R2=0.999 7),吸附等温线与Langmuir吸附等温方程拟合良好(R^2=0.999 9),最大吸附量为17.035 8mg/g。

With the mass fraction of available chlorine, modification time and liquor ratio （rat io of NaCIO solu-tion volume on silk mass） as three significant factors and the silk recovery rate as response value,the experiment was designed to optimize the silk modification process by response surface methodology. The adsorption ability of modified silk on Zn2＋ was researched. The results showed that the quadratic regression equation of silk recovery rate on three elements had high significance （P = 0.000 4 ,R^2 = 0 .961 6） ,and the lack of fit was not significant （ P = 0.9002） . So the quadratic regression equation well fitted with the actual experiment. After optimization analysis？the best silk modifi-cation process had been found that mass fraction of available chlorine was 2.00% ,that modification time was 10 h and that liquor ratio was 600 mL/g.In this condition, the silk recovery rate was about 58.30%. When the pH was 6.5 tem-perature was 30 ℃ ,adsorption time was 420 min,shaking speed was 150 r/min and solid-liquid ratio （ratio of modi-fied silk mass on volume of Zn2＋ containning simulated wastewater） was 1 g/L,the Zn^2＋ adsorption by modified silk was very fast at first,and reached balance in 240 min. The adsorption kinetics well fitted Lagergren pseudo-second ki-netic equation （ R^2 =0.999 7） ,and the adsorption isotherm well fitted Langmuir adsorption isotherm equation （ R^2 = 0.999 9）,with the maximum adsorption amount of Zn2＋ by modified silk 17.035 8 mg/g.