中文摘要：

研究了从二壬基萘磺酸-二（2-乙基己基）膦酸（DNNSA-P204）负载有机相中反萃铅的影响因素.考察了反萃剂种类、反萃时间、反萃温度、反萃剂浓度和反萃油水比（VO/VA）对负载有机相中铅反萃的影响.实验结果表明,硝酸为最佳反萃剂,反萃平衡的时间为5 min,低温有利于反萃.反萃过程为放热过程,过程焓变为-942.7 J·mol-1.广角激光光散射和FT-IR结果表明：DNNSA浓度不变时,DNNSA-P204形成的混合反胶团随着P204浓度的增加而变大,负载有机相中的铅以PbAD形式增溶进入混合反胶团内水相中.经多次反萃后,萃取剂DNNSA-P204对铅仍有较好的萃取能力.当反萃时间为5 min,温度为298 K,油水比为2∶1,硝酸浓度为0.6 mol·L-1时,反萃率可达到70％.

英文摘要：

The influencing factors on the back-extraction of lead from lead-loaded dinonylnaphthalene sulfonic acid-di （2-ethylhexyl） phosphonic acid （DNNSA-P204） kerosene solution were investigated. The effects of stripping agents, stripping time, temperature, stripping agent concentration and phase ratio（ Vo/VA ） were determined. It was found that the most suitable stripping agent was nitric acid, and the equilibrium was attained in 5min. Low temperature had a positive effect on the back-extraction of lead ions. The enthalpy of activation AH was calculated to be -942.7 J· mol-l , indicating that the extraction of Pb （ Ⅱ ） was exothermic reaction in the investigated system. Wide angle laser light scattering and FT-IR spectra results confirmed that the size of the DNNSA-P204 reverse micelles increased with the adding of the P204 concentration when the DNNSA concentration kept constant, pronmting the solubility of Pb （Ⅱ ） in organic phase into inner water pools as PbAD. The extraction-stripping cycles of Pb （ Ⅱ ） were repeated and the results showed that the stripping agent nitric acid was promising. DNNSA-P204 reverse micelles solution could be repeatedly used for the extraction of Pb （ Ⅱ ） from waste water. Under optimal operation conditions with back-extraction time of 5 rain, back-extraction temperature of 298K, phase ratio （ Vo/VA ） of 2 ： 1, and nitric acid concentration of 0.6mol·L-1, the yield of back-extraction can reach 70%.