改性地瓜茎对废水中结晶紫的吸附性能

Tadsorption of Crystal Violet from Waste Water Using Modified Stem of Ipomoea batatas Lam

采用改性地瓜茎作为新型生物吸附剂对模拟废水中结晶紫进行吸附去除,探讨吸附剂用量、pH、反应时间和染料初始质量浓度对结晶紫去除率的影响,并利用Box-Behnken响应曲面法优化吸附条件。结果表明,当pH为10、吸附剂用量为0.2g、结晶紫初始质量浓度为600mg/L和反应时间为60min时,改性地瓜茎对废水中结晶紫的最大去除率为97.9%。准二级动力学模型对试验数据的拟合效果最好,表明该吸附以离子交换吸附为主。与Freundlich和Temkin等温吸附方程相比,Langmuir模型对试验数据的拟合效果最好,表明结晶紫在地瓜茎表面的吸附以单分子层吸附为主。

The modified stem of Ipomoea batatas Lam,a new biosorbent,was used for the adsorption of crystal violet from stimulated waste water.The effect of pH,adsorbent dosage,contact time and initial concentration on removing rate of crystal violet were investigated by batch experiment,and the optimized adsorption condition was conducted by the Box-Behnken response surface methodology.The results indicate that when solution pH was 10,adsorbent dosage was 0.2g,the initial concentration was 600mg/L and contact time was 60 min,the maximal removal rate of crystal violet reached 97.9%.The pseudo-second kinetic model best fits the experimental data,indicating that the adsorption process is mainly ion exchange adsorption.The overall isothermal adsorption data is satisfactorily explained by a Langmuir isotherm adsorption model than Freundlich and Temkin equation,which indicates that the adsorption process is mainly monomolecular layer adsorption.