Mass Transfer Studies in Pulsed Sieve Plate Extraction Column for the Removal of Tributyl Phosphate from Aqueous Nitric Acid

Removal of a saturated amount of tributyl phosphate (TBP) from a nuclear reprocessing aqueous waste stream is very important as far as economy of process as well as waste disposal is concerned. The present research work describes the detailed mass transfer studies for the removal of TBP from aqueous stream in a geometrically optimized pulsed sieve plate extraction column (PSPEC). The original industrial system, viz., 0.3 M nitric acid-TBP-normal paraffinic hydrocarbon (NPH), was used for the mass transfer studies. The effect of operating parameters such as continuous to dispersed phase velocity ratio and pulsed velocity on the volumetric mass transfer coefficient was investigated. The effect of operating parameters on the variation in axial concentration and holdup profile is also studied to evaluate the dynamic operation of the column for the attainment of steady state. The experimental results indicate that pulse velocity has a strong effect on the volumetric mass transfer coefficient, while the effect of the continuous phase flow rate is greater than the effect of the dispersed phase flow rate.