Rajasimman M, Sangeetha R
Department of Chemical Engineering, Annamalai University, Annamalai Nagar, Chidambaram, Tamil Nadu, India.
J Hazard Mater. 2009 Aug 30;168(1):291-7. doi: 10.1016/j.jhazmat.2009.02.044. Epub 2009 Feb 21.
The emulsion liquid membrane technique was used for the extraction of hexavalent chromium ions from aqueous solution of waste sodium dichromate recovered from the pharmaceutical industry wastewater. The liquid membrane used was composed of kerosene oil as the solvent, Span-80 as the surfactant and potassium hydroxide as internal reagent. Trioctyl amine and Aliquat-336 were used as carriers. The emulsion stability was carried out at different surfactant concentration, agitation speed and emulsification time. Statistical experimental design was applied for the optimization of process parameters for the extraction of chromium by emulsion liquid membrane. The effects of process parameters namely, agitation speed, membrane to emulsion (M/E) ratio and carrier concentration on the extraction of chromium were optimized using a response surface method. The optimum conditions for the extraction of chromium (VI) using response surface methodology for Trioctyl amine were: agitation speed--201.369rpm, M/E ratio--0.5887% (v/v) and carrier concentration--4.0932% (v/v) and for Aliquat-336: agitation speed--202.097 rpm, M/E ratio--0.5873% (v/v) and carrier concentration --3.9211% (v/v). At the optimized condition the maximum chromium extraction was found to be 89.2% and 96.15% using Trioctyl amine and Aliquat-336, respectively.
采用乳化液膜技术从制药工业废水回收的废重铬酸钠水溶液中提取六价铬离子。所用的液膜由煤油作为溶剂、Span - 80作为表面活性剂和氢氧化钾作为内相试剂组成。三辛胺和Aliquat - 336用作载体。在不同的表面活性剂浓度、搅拌速度和乳化时间下进行了乳液稳定性实验。应用统计实验设计来优化乳化液膜提取铬的工艺参数。采用响应面法优化了搅拌速度、膜相/乳液相（M/E）比和载体浓度等工艺参数对铬提取率的影响。使用响应面法，以三辛胺为载体时，提取铬（VI）的最佳条件为：搅拌速度 - 201.369rpm，M/E比 - 0.5887%（v/v），载体浓度 - 4.0932%（v/v）；以Aliquat - 336为载体时：搅拌速度 - 202.097rpm，M/E比 - 0.5873%（v/v），载体浓度 - 3.9211%（v/v）。在优化条件下，使用三辛胺和Aliquat - 336时，铬的最大提取率分别为89.2%和96.15%。
