화학공학소재연구정보센터
Separation Science and Technology, Vol.48, No.3, 445-454, 2013
Electrodialysis in an Integrated NF/ED Process for Water Recovery in the Leather Industry
Electrodialysis (ED) was assessed for integration in a nanofiltration NF/ED sequence for water reuse in the leather industry. Two ED feeds composed of different model solutions were used: Model Solution FED1, which is a surrogate of a nanofiltration permeate generated by the NF processing of a biologically treated leather effluent, and Model Solution FED2, which has the same salt concentration as FED1 but with an organic matter content that is approximately ten times higher. The electrodialysis experiments were carried out in a five-compartment bench cell using cationic and anionic membranes HDX 100 and HDX 200. The final product water, with a conductivity ranging from 3.28 to 3.67 mS cm-1, can be reused as process water for beamhouse operations. With respect to chloride and COD parameters, the ED product water meets the requirements of process water, even for dyeing operations. An alkaline membrane cleaning process for fouling removal was also tested for the membranes using Model Solution FED2. The cleaned membranes were evaluated in terms of visual aspect, polarization curves, TGA, and SEM/EDS analysis. The results obtained with the cleaned membranes were very similar to those obtained with the new ones in ED experiments with Model Solution FED2.