Kinetic Analysis of the Simultaneous Nondispersive Extraction and Back-Extraction of Chromium(VI)

This work has been focused on the study of the viability and kinetics of Cr(VI) removal from industrial waste waters and simultaneous concentration for its reuse in electroplating processes, working with liquid−liquid systems in two hollow-fiber (HF) modules, and using Aliquat 336 as an organic carrier. For the kinetic analysis of the non-steady-state system the macroscopic mass balances of the chromium in the fluid phases into HF modules were developed and solved simultaneously with the mass balances in the homogenization stirred tanks. An optimization procedure to calculate the mass transport parameters was developed, leading to the value K m = 1.92 × 10 - 8 m/s (membrane mass-transport coefficient). In the extraction process a kinetic mass-transfer parameter depending on the experimental conditions was obtained.