Emulsion pertraction

Bringas, E., San Roman, M.F. and Ortiz, I. (2006) Separation and recovery of anionic pollutants by the emulsion pertraction technology. Remediation of polluted... 

San Roman, M.F., Bringas, E., Ortiz, I. and Grossmann, I.E. (2007) Optimal synthesis of an emulsion pertraction process for the removal of pollutant anions in industrial wastewater systems. Comp Chem Eng, 31, 456. 

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. 

As mentioned in the introduction section, an emerging alternative to achieve the separation of metallic pollutants from aqueous effluents and their concentration in a receiving phase is the emulsion pertraction technology using HF modules. 

FIGURE 37.4 Flow diagram of an emulsion pertraction process, where... 

FIGURE 37.5 Experimental results of a representative emulsion pertraction run. 

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. 

Optimal Operating Conditions of an Emulsion Pertraction Plant for Chromium(VI) Recovery... 

FIGURE 39.6 Emulsion pertraction installation at Rogal, Enschede, the Netherlands. (From Klaassen R. and Jansen, A.E., Environ. Prog., 20, 37, 2001. With permission.)... 

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. 

Promising results are shown by recently developed integrated SLM-ELM [84, 85] systems. These techniques are known as supported liquid membrane with strip dispersion (SLMSD), pseudo-emulsion-based hollow fiber strip dispersion (PEHFSD), emulsion pertraction technology (EPP), and strip dispersion hybrid Hquid membrane (SDHLM). AH techniques are the same the organic phase (carrier, dissolved in diluent) and back extraction aqueous phase are emulsified before injection into the module and can be separated at the module outlet. The difference is only in the type of the SLM contactors hoUow fiber or flat sheet and in the Hquid membrane (carrier) composition. These techniques have been successfuUy demonstrated for the removal and recovery of metals from wastewaters. Nevertheless, the techniques stiU need to be tested in specific apphcations to evaluate the suitabUity of the technology for commercial use. 

An emulsion pertraction pilot installation has been tested on-site at the Rogal facilities in Enschede (Netherlands) to extend the lifetime of their passivating bath. The installation is equipped with PP membranes [1,107,108]. 

In the framework of the EU Life project Empereur, two full-scale emulsion pertraction installations have been built and are demonstrated at the site of the galvanic firms Loko Gramsbergen and Galvano Techniek Veenendaal (GTV), both in the Netherlands. In this technique, however, the dispersion of one liquid phase in another is not created via a membrane but rather externally in a mixer/dispersion device. This technique has also been identified as a supported liquid membrane with a strip dispersion and has been employed in a large-scale installation (Figure 4.12). More details are provided in [103,107],... 

Emulsion pertraction is a combination of the two types of liquid membrane process where an unstabilized water-in-oil emulsion is fed down the lumen of a hollow fiber that is surrounded by the aqueous feed. 

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