新型茶皂素硫酸钠合成及其修复土壤重金属污染研究

经水提-沉淀法从茶籽饼提取茶皂素,以其为原料设计合成了新型绿色茶皂素基螯合剂(茶皂素硫酸钠)。对其表面性能进行研究发现,其表面张力低于茶皂素,而HLB值、起泡力及稳泡性均优于茶皂素。同时考察了振荡时间、螯合剂浓度、pH及离子强度对螯合剂去除重金属率的影响。结果表明,重金属去除率随振荡时间和浓度增加而升高,随pH、离子强度增加而降低。得出去除Pb2+、Cd2+离子的最佳工艺:振荡时间为12h,质量分数为7%,pH为5.0,Ca(NO3)2浓度为0.01mol/L,此条件下螯合剂对土壤中Pb2+、Cd2+离子去除率最大,茶皂素硫酸钠对Cd2+离子的去除率大于Pb2+离子,且茶皂素硫酸钠对此2种离子的去除率均优于茶皂素,尤其对Pb2+离子去除率改善效果显著。

Preparation of New-type Tea Saponin Sodium Sulfate and Its Remediation Study on Soil Heavy Metal Pollution

The neotype green tea-saponin chelate(tea saponin sodium sulfate) were prepared by the tea saponin as raw material extracted through aqueous extract-alcohol precipitation from tea seed cake.After the research to its superficial performance,the results showed the surface tension of tea saponin sodium sulfate was lower than the TS’s,but HLB value and foaming and stable foam ability were higher than TS’s.Meanwhile the effect of the oscillation time,chelating agent concentration,pH and ionic strength on removing heavy metal rate was investigated.The results showed that the removal rate of heavy metal ions increased with oscillation time and chelating agent concentration increasing,reduced with ionic strength and pH increasing.The optimum technologies of removal of Pb2+,Cd2+ were as follows:Oscillation time was 12 h,chelating agent mass concentration was 7%,pH was 5.0,concentration of Ca(NO3)2 was 0.01 mol/L.On the conditions,removal rate of Pb2+ and Cd2+ ions in the soil by chelating agent was the highest.Removal rate of Cd2+ of tea-saponin sodium sulfate was higher than Pb2+’s.Removal rate of Pb2+ and Cd2+ of tea-saponin sodium sulfate was better than tea saponin’s respectively.Especially,removal rate of Pb2+ of tea-saponin sodium sulfate was significantly improved.