胶体滴定法测定采油污水中部分水解聚丙烯酰胺的浓度

Determination of Concentration of Partially Hydro-lyzed Polyacrylamide in Waste from Oil Extraction by Colloidal Titration

关键词:  胶体滴定法  部分水解聚丙烯酰胺  采油污水  浓度

Key words:  colloidal titration  hydrolyzed polyacryl-amide  concentration

摘要:

应用胶体滴定技术建立了采油污水中部分水解聚丙烯酰胺(HPAM)浓度的分析方法。探讨了pH值、水解度、矿化度、含油量、粘均相对分子质量和滴定速度对胶体滴定法的影响。实验结果表明,在pH值为9～10,HPAM溶液浓度在5 mg/L～200 mg/L时,其电荷量(以滴定值表示)与对应浓度呈良好的线性关系。采出液中水相的矿化度和低于50 mg/L的含油量以及HPAM的粘均相对分子质量对胶体滴定值无明显影响,但水解度会影响胶体滴定值。滴定速度应控制在0.02 mL/s左右。HPAM的平均回收率为99.89%,相对标准偏差为5.35%。胶体滴定法和淀粉-碘化镉法测定的油田采出液中HPAM的浓度差值小于5 mg/L。与淀粉-碘化镉法相比,胶体滴定法具有所用试剂无毒、对环境无污染、操作简便快速、结果准确、适合在现场监测使用的特点。

Abstract:

Method of colloidal titration was estab-lished to determine concentration of the partially hydrolyzed polyacrylamide (HPAM) in the waste from oil extraction.Effects of pH value,hydrolysis degree,mineralization degree,oil content,viscosity-average relative molecular masses and titration speed on colloidal titration were investigated. The results showed that the concentration of HPAM is correlated linearly with electric charge quantity (expressed as titration value) in the mass range of HPAM from 5mg/L to 200mg/L at pH9～10. Mineralization degree,oil content(less than 50mg/L) and viscosity-average relative molecular masses of the extract had no obvious effect on titration val-ue,but hydrolysis degree is opposite. Titration speed should be about 0.02 mL/s. Average recovery of HPAM is 99.89%,and relative standard deviation is 5. 35%. Compared with starch-cadminum method,a difference of the concentration of the hydrolyzed polyacrylamide is less than 5mg/L,and colloidal titration has the advantages of reagent nontoxic,non-pollution,simplicity,rapidity,and accuracy,so it is very suitable for the monitoring on site.