"铅树"生成的绿色化改进研究

目的探讨"铅树"生成实验最佳条件,并进行绿色化改进。方法通过设计响应曲面并建立数学模型,在单因素实验的基础上对"铅树"实验进行优化,考察pH值、硝酸铅浓度、成胶温度3个自变量对实验中刚生成胶冻所需的时间t_1和锌片表面出现明显树状现象所需的时间t_2的影响。结果在所建数学模型中,以硝酸铅浓度最低为前提,最佳实验条件:成胶温度90℃,硝酸铅浓度0.23mol/L,pH值5.52,此条件下t_1=3.32min、t_2=15.51min,实际值t_1=3.33min、t_2=15.33min。结论经改进,实验总时间可控制在0.5h内,实验成功率显著提高,且有效减少了铅及其化合物的使用量。

Study on the green improvement of producing "Lead Tree"

Purposes-To explore the best conditions for the preparation of "Lead Tree" and improve the preparation greenly.MethodsThe experiment for preparation of "Lead Tree" was optimized with response surface methodology and by establishing mathematical model.On the basis of the single factor test, three independent variables, that is, pH, concentration of Pb(NO3)2 and reaction temperature, were studied about the effect on t1 (the time required to generate gel) and t2 (the time required for the appearance of significant tree phenomenon on the zinc surface).ResultsIn the mathematical model, with the lowest concentration of Pb(NO3)2 as a premise, the optimum conditions are as follows: temperature is 90 ℃, pH is 5.52 and the concentration of Pb(NO3)2 is 0.23 mol/L.Under these conditions, t1=3.32 mins and t2=15.51 mins, while the actual value of t1 and t2 are 3.33 mins and 15.33 mins, respectively.Conclusions-By this improvement, the total time of experiment was controlled within 0.5 h, the success rate was greatly improved, which reduced the dosage of lead and its compounds effectively.