Electrodialysis optimization

The copper(II) flux is directly proportional to the cuiTent density up to 10 mPJcrcf. The extraction degree of platinum(IV) into the strip solution is less than 0.1 % per hour of electrodialysis. About 55% of copper(II) is removed from the feed solution under optimal conditions. The copper(II) extraction process is characterized by high selectivity. Maximum separation factor exceeds 900 in the studied system. 

Cooling Water Salinity and Brine Disposal Optimized with Electrodialysis Water Recovery/Brine Concentration System... 

This paper reviews the most recent innovations in electrodialysis (ED) modules and/or processes that appear to affect the food and drinks industries in the short-medium term, together with their basic mass transport equations that might help ED unit design or optimization. Future perspectives for ED processing in the food sector are also outlined. 

Sonin, A.A. and Isaacson, M.S. 1974. Optimization of flow design in forced flow electrochemical systems with special application to electrodialysis. Ind. Eng. Chem. Process Des. Develop. 13, 241-248. 

A. Elmidaoui, F. Elhanouni, M. Taky, L. Chay, M.A.M. Sahli, L. Echihabi, M. Hafsi, Optimization of nitrate removal operation from ground water by electrodialysis, Sep. Purif. Technol. 29 (2002) 235-244. 

The state-of-the-art in membrane techniques is shown in the figure ( via[8])where the advances in individual membrane operations are defined in terms of availability, service reliability, and price warranty. Research on the first group of methods primarily covers process optimization problems. From the data included in the figure, it is obvious that by far the most advanced methods are the long established membrane processes such as dialysis, microfiltration, ultrafiltration, hyperfiltration, reverse osmosis and electrodialysis. It is also evident that the dynamics of sale shows a tendency to decrease. 

From the experimental results, we concluded that electrical energy demand AG for electrodialysis of Hix solution decreases with increasing temperature. Moreover, the electrodialysis cell overpotential is primarily influenced by the system resistance and hence the thermal efficiency of the cell could be improved by reducing the constituent resistance and by optimizing the cell assembly. 

Z. Amor, S. Malki, M. Taky, B. Bariou, N. Mameri and A. Elmidaoui, Optimization of fluoride removal from brackish water by electrodialysis, Desalination, 1998, 120, 263 D. Cohen and H.M. Conrad, 65,000 GPD fluoride removal membrane system in Lakeland, California, Desalination, 1998, 117, 19 P. Brandhuber and G. Amy, Alternative methods for membrane filtration for drinking water, Desalination, 1998, 117, 1. 

The optimum operation of electrodialysis is the same concept as that of electrolysis using ion exchange membranes. Namely, the sum of investment and running costs decides optimal operation conditions. When production capacity by electrodialysis, Q, is expressed as... 

About 1.4 million tons of sodium chloride (edible salt)/year has been produced in Japan since 1972 by the electrodialytic concentration of seawater. This technology has been exported to Korea, Taiwan and Kuwait. After seawater is concentrated up to about seven times or more its initial concentration by electrodialysis, an optimal concentration from an economic viewpoint, sodium chloride is produced by evaporating the concentrated solution. Table 6.4 shows a typical composition of the concentrated solution.51 In this process, monovalent cation and anion permselective ion exchange membranes have been used. This technology was developed in Japan to produce sodium chloride by the electro-... 

Membrane unit operations such as microfiltration (MF), ultrafiltration (UF), nanoflltration (NF), reverse osmosis (RO), electrodialysis (ED) and gas separation (GS) are well-established applications today at industrial level offering interesting opportunities in the rationalization and optimization of productive cycles. 

Paleologou M.Thibault A.Wong P-Y, Thompson R, Berry RM. Optimization of two-compartment bipolar membrane electrodialysis system for the production of sodium hydroxide and sulfuric acid from sodium sulfate generated at kraft mills using ECF and TCP bleaching sequences. In Proc symp minimum ejfluent mi7/s. Atlanta (GA, USA) TAPPI Press 1996. p. 381—4. 

To cope with this, the process was further optimized by operating the system as a microbial electrodialysis cell (MEDC). The energy efficiencies obtained (tie) in the MEDCs reached 231 59% (5 gP NaCl) and 213 38% (20 gl NaCl), suggesting that sufficient hydrogen was produced to power the MEDC [148]. 

The other bottleneck for lactic acid production is the operating cost. For example, sterilization is necessary for fermentative production. Hence, microorganisms have an optimal fermentation temperature between 30 2°C (John et al., 2007). Therefore it is difficult to avoid contamination if the medium is not sterilized. Qin et al. (2009) have reported the use of a newly isolated thermophilic strain. Bacillus sp. strain 2 to 6, for the unsterilized fermentative production of L-lactic acid. A high yield (97.3%), productivity (4.37g/L/h), and optical purity of L-lactic acid (99.4%) were obtained in batch and fed-batch open fermentations (Qin et al., 2009). This will help to reduce energy consumption and lower labor costs. Moreover, because of the inhibitory effects of a low pH on cell growth and lactic acid production, CaCOs must be added to maintain a constant pH as a consequence, the regeneration of precipitated calcium lactate is observed (Datta and Henry, 2006). To solve this problem, a sodium lactate-tolerant strain. Bacillus sp. Na-2, was obtained by ion-beam implantation and applied during an L-lactic acid production process (Qin et al., 2010). On the other hand, new processes can be applied to prevent the production of calcium lactate, for example, reverse osmosis, ultrafiltration, electrodialysis, and solvent extraction (Datta and Henry, 2006). 

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