Combined electrolysis and micellar enhanced ultrafiltration (MEUF) process for metal removal

A novel hybrid treatment process combining electrolysis process and micellar enhanced ultrafiltration process (MEUF) is proposed for removing metals. While MEUF is employed to retain metals inside the reactor, the electrolysis process liberates metal ions from the surfactant micelle-metal complexes and continuously removes these liberated ions by electroplating them onto the cathode. Subsequently, the metal-free micelles are able to retain more metal ions entering the reactor afterward. Thus, the proposed hybrid system is operated as a continuous adsorption (by MEUF) and regeneration (by electrolysis) process. Using the proposed setup, the hydraulic retention time (HRT) is substantially reduced to less than 15 min as compared to more than 80 min needed using the conventional electrolysis process for achieving the similar metal removal efficiency. In addition, the hybrid system achieves higher electrolysis current efficiency than does the conventional electrolytic process, and uses less surfactant than does the conventional MEUF. The metal removal efficiency of the hybrid system increases with increasing in surfactant concentration, electrolytic voltage, hydraulic detention time. (C) 2004 Elsevier B.V. All rights reserved.