Emulsion pertraction modeling

More recently HF modules have been used in a different configuration that based on similar fundamentals tries to minimize the required membrane area, that is, emulsion pertraction technology. In this case, the organic and back-extraction phases are emulsified before the entrance to the HF module and they can be separated at the module outlet. Although there are only a few references to this alternative, its viability to the recovery of Cr(Vl) and Cu from polluted waters [44 6] as well as to the removal of hydrocarbons [47] has been shown, but much effort is needed on the modeling of this technology before additional successful applications can be developed. 

In this section, the reported model and the parameters wiU be used to obtain the optimal operation point that maximizes the amount of Cr treated in an emulsion pertraction plant. It is considered that the plant operates continuously and the reduction target value of Cr(VI) in the effluent as well as the concentration levels are fixed values equal to 0.00961 mol/m (0.5 mg/L) and 384.615 mol/m (20,000 mg/L), respectively. 

Ortiz, I., Fresnedo San Roman, M., Corvalan, S., Eliceche, A. M. (2003). Modeling and optimization of an Emulsion Pertraction Process for Removal and Concentration ofCr(VI). Industrial Engineering Chemistry Research 42 5891-5899. 

Modeling and optimization of pertraction into emulsion in HF contactors is discussed in refs. [77, 138]. The design and optimization of a network of HF contactors with minimum cost that permits the selective separation and recovery of anionic pollutants, for example, Cr(VI), using BLME process for groundwater remediation is presented in ref. [139] and for waste-water treatment in ref. [140]. 

Yordanov B and Boyadzhiev L. Pertraction of citric acid by means of emulsion liquid membranes. J Membr Sci 2004 238 191-197. Lin CC and Long RL. Removal of nitric acid by emulsion liquid membrane experimental results and model prediction. J Membr Sci... 

The model for the pertraction process has been explained in the previous section. A system of partial differential equations describes the behavior of the aqueous and emulsion phases, and ordinary differential equations describe the dynamic behavior of the tanks. There is also a set of algebraic equations for the chemical equilibrium and connections between the equipment. 

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