改性白菜叶渣对重金属Zn^(2+)吸附性能

Adsorption performance of heavy metal Zn^(2+) by modified cabbage

为了研究白菜叶渣对锌离子的吸附作用,采用静态吸附的方法,以酸碱处理后的废弃白菜渣为原材料,获得加入量(X1)、浓度(X2)、时间(X3)、pH(X4)和温度(X5)各单因素对Zn2+的最佳吸附点,再通过二次回归正交旋转组合设计对白菜渣吸附Zn2+的条件进行优化,并讨论了吸附过程中吸附等温线与动力曲线的相关特征。结果表明,当加入量0.2g、浓度2 mg/L、吸附时间5 h、pH为4以及温度20℃时,吸附达到最大95.08%,验证所测最大吸附率93.89%,与预测值基本相符。对比实验说明白菜渣对Zn2吸附效果要优于活性炭。25℃和35℃时的等温线的拟合结果表明,白菜渣对Zn2+是物理化学共同吸附的复杂过程。

The experiment was conducted to study the adsorption effect of abandoned cabbage on Zn2＋ , which was based on static adsorption. The maximum absorption rate was obtained by regulating different factors involving addition （ X1 ） , concentration （X2 ） , time （X3 ） , pH （X4 ） , temperature （X5 respectively. Experimental factors was optimized by quadratic regression orthogonal rotating combination design,as well as the related char- acterizations of adsorption isotherm and kinetic model were examined. The results showed that the zinc ions were absorbed by cabbage slag up to maximum of 95.08% under the condition that addition 0.2 g,2 mg/L of Zn2＋ , pH 4,5 h and 40℃. The experimental result reached 93.89% and was nearly consistent with forecast value. The comparison test demonstrated the cabbage slag was a better absorbent compared with activated carbon. According to the adsorption isotherm at 25℃ and 35℃ ,the adsorption of Zn2＋ by abandoned cabbage slag should be regar- ded as a complex process in which chemical and physical absorption function altogether.