ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Effective removal of Congo red using sunflower oil/tri-n-octylamine system in a bulk liquid membrane process and studying the transport kinetics

Vikas Kumar, Yogesh Karnjkar, Prince George, Raghubansh K. Singh, and Pradip Chowdhury

National Institution of Technology Rourkela, Rourkela, India

E-mail: chowdhuryp@nitrkl.ac.in

Abstract: The present work highlights effective transport and removal of Congo red (CR) from its model solution using sunflower oil/tri-n-octylamine (TOA) system in bulk liquid membrane (BLM) transport. Aqueous solution of Na₂CO₃ with 1 M solution strength was found to be an effective stripping medium for the anionic dye transport. Maximum extraction and recovery percentages of 99.9 and 75.6% were achieved when optimum manifold operating conditions were: 4 vol.% TOA, 2 ± 0.1 feed phase pH, 300 rpm stirring speed, at 40 °C temperature with 8 h, equilibrium time. Kinetic estimation of data with higher rate constants for extraction vis-à-vis stripping operation throughout various experimental conditions suggested that CR transport across sunflower oil/TOA BLM system was governed by stripping process. Activation energies for extraction and stripping operations were found to be 45.92 and 74.05 kJ mol⁻¹, respectively. This led to a conclusion that the rate determining step for extraction was intermediate controlled whereas for stripping it was chemical reaction rate controlled. Finally, spectral studies (UV–vis and FT-IR) were carried out to confirm and validate the recovery of CR.

Keywords: Congo red ; Sunflower oil ; Tri-n-octylamine ; Bulk liquid membrane ; Transport kinetics 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-018-0438-2

Chemical Papers 72 (8) 2055–2069 (2018)