论文部分内容阅读
研究了双水相萃取废液中聚乙二醇的回收利用,旨在降低生产成本,减少COD排放,推动双水相萃取技术的工业应用进程。以聚乙二醇-硫酸铵[PEG-(NH4)2SO4]组成的双水相体系废液为原料,采用脱色、浓缩、洗涤除去杂质的工艺技术路线,确定了从双水相废液中回收成相聚合物PEG的最佳工艺(:1)利用H2O2法脱色,最佳脱色条件:H2O2浓度为6%,脱色温度为60℃,脱色时间为4 h,体系pH值为9.0,脱色率达到85%以上(;2)采取盐析法浓缩,最佳电解质种类为Na2SO4,最佳加入量为每10 mL废液3.0 g Na2SO4,此时PEG浓缩比为3.45,PEG损失率为0.31%。按照药用级PEG产品质量标准,对干燥后的回收物进行质量检测。结果表明:回收的PEG产品外观呈浅黄色蜡状,电导率为10.8μs/cm,凝固点为37～40℃,pH值(5%水溶液)为6.33,较纯品PEG无明显差异。
The recycling of polyethylene glycol in aqueous two-phase extraction was studied in order to reduce the production cost, reduce the COD discharge and promote the industrial application of aqueous two-phase extraction. The technological process of removing impurities by decolorization, concentration and washing was determined by using aqueous two-phase system of polyethylene glycol-ammonium sulfate [PEG- (NH4) 2SO4] as raw material, The optimum conditions for the formation of polymer PEG: (1) Decolorization by H2O2, the optimum decolorization conditions: H2O2 concentration of 6%, decolorization temperature of 60 ℃, bleaching time of 4 h, the system pH value of 9.0, the decolorization rate reached More than 85% (2) was concentrated by salting-out method. The optimal electrolyte type was Na2SO4. The optimal addition amount was 3.0 g Na2SO4 per 10 mL waste liquid. The PEG concentration ratio was 3.45 and the PEG loss rate was 0.31%. In accordance with the pharmaceutical-grade PEG product quality standards, the recovery of dried products for quality testing. The results showed that the appearance of the recovered PEG product was light yellow wax, the conductivity was 10.8μs / cm, the freezing point was 37 ~ 40 ℃, and the pH value (5% aqueous solution) was 6.33.