Extraction of aniline from wastewater: equilibria, model, and fitting of apparent extraction equilibrium constants
Extraction of aniline from wastewater: equilibria, model, and fitting of apparent extraction equilibrium constants
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从废水中萃取苯胺：表观萃取平衡常数的平衡、模型和拟合
DOI：
10.1039/c5ra20802e
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发表时间：
2016-01-01
期刊：
影响因子：
3.9
通讯作者：
Ren, Zhongqi
中科院分区：
文献类型：
--
作者：
Chai, Wenshuai;Zhu, Xinyan;Ren, Zhongqi
研究了298.2 ± 0.5K下苯胺的物理萃取平衡和反应萃取平衡。采用乙酸丁酯（BA）、正癸醇、正庚烷和甲基叔丁基醚（MTBE）进行物理萃取。苯胺的分配系数（D）为BA > MTBE >正癸醇>正庚烷。由于BA的极性较强，其分配系数最大（D = 22.58）。平衡温度对分配系数几乎没有影响，但对MTBE影响不大。以磷酸三丁酯（TBP）、乙酰胺（N503）、三烷基胺（N235）、二（2-乙基己基）磷酸（D2 EHPA）和（2-乙基己基）-2-乙基己基膦酸酯（P507）为萃取剂，BA、煤油和正庚烷为稀释剂进行反应萃取。TBP、N503和N235由于其中性和碱性的特性，去除能力较弱。对于酸性含磷萃取剂，即，D2 EHPA和P507，平衡模型，采用质量作用定律，并用于确定模型参数和表观萃取平衡常数（K-11，K-12，和K-21）。反应萃取络合物被认为是1：1和1：2苯胺与D2 EHPA络合物与BA作为稀释剂，1：2苯胺与D2 EHPA络合物与煤油和正庚烷作为稀释剂，和1：1和1：2苯胺与P507络合物与煤油和正庚烷作为稀释剂。用该模型参数和表观萃取平衡常数计算的D2 EHPA和P507的分配系数和负载量与实验数据吻合较好，表明该模型能较好地描述苯胺与所选萃取剂在反应萃取中的平衡行为。考察了温度对萃取能力的影响，得到了D2 EHPA在煤油中萃取过程的焓变。
The physical and reactive extraction equilibria of aniline at 298.2 +/- 0.5 K were studied. n-Butylacetate (BA), ndecanol, n-heptane and methyl tert-butyl ether (MTBE) were used for physical extraction. The distribution coefficient (D) of aniline follows the sequence BA > MTBE > n-decanol > n-heptane. The largest distribution coefficient (D = 22.58) can be obtained with BA owing to its strong polarity. The equilibrium temperature almost has no effect on the distribution coefficient except for MTBE. Tributyl phosphate (TBP), acetamide (N503), trialkylamine (N235), di-(2-ethylhexyl) phosphoric acid (D2EHPA) and (2-ethylhexyl) 2ethylhexylphosphanate (P507) were used as extractants with BA, kerosene and n-heptane as diluents for the reactive extraction. TBP, N503 and N235 show weak removal abilities because of their neutral and basic characteristics. For the acidic phosphorus-containing extractants, namely, D2EHPA and P507, equilibrium models are presented that employ the mass action law and used to determine model parameters and apparent extraction equilibrium constants (K-11, K-12, and K-21). The reactive extraction complexes are considered as 1 : 1 and 1 : 2 aniline to D2EHPA complexes with BA as diluent, 1 : 2 aniline to D2EHPA complexes with kerosene and n-heptane as diluents, and 1 : 1 and 1 : 2 aniline to P507 complexes with kerosene and nheptane as diluents. The distribution coefficients and loadings of D2EHPA and P507 calculated using the equilibrium model parameters and apparent extraction equilibrium constants efficiently agree with the experimental data, which indicates that the models are valid in representing the equilibrium behavior of aniline with the selected extractants in reactive extraction. The effects of temperature on extraction abilities were investigated and the enthalpy change of the extraction process with D2EHPA in kerosene was obtained.