Kinetics, thermodynamic, and adsorption studies on removal of chromium(VI) using Tulsion A-27(MP) resin

Abstract

A B S T R A C TThe kinetics, thermodynamic, and adsorption studies on removal of chromium(VI) from aqueous and in presence of industrial solvents 2-methoxyethanol and 2-ethoxyethanol with macroporous resin Tulsion A-27 was studied at varying concentration of Cr(VI), adsorbent dosage, pH, contact time, and temperature. Batch shaking sorption experiments were carried out to evaluate the performance of Tulsion A-27(MP) anion exchange resin in the removal of Cr(VI) from aqueous and mixed aqueous solvents, 2-methoxyethanol and 2-ethoxyethanol. The concentrations of Cr(VI) in aqueous and mixed aqueous solvents were determined by UV-Visible spectrophotometer. As the adsorption process is pH dependent, it showed maximum removal efficiency of Cr(VI) in the pH range of 5-6 for an initial chromium concentration of 0.0011 M. Effect of temperature on the equilibrium constant was studied and the thermodynamic parameters were evaluated. Kinetic experiments revealed the dominance of adsorption. The sorption models, Langmuir and Freundlich adsorption isotherms, were discussed on amount of Cr(VI) uptake. The resin was analyzed by infrared spectroscopy and scanning electron microscopy before and after the adsorption process. The sorption of Cr(VI) by the anion exchange resin was reversible and so it has good potential for the removal/ recovery of Cr(VI) from aqueous and mixed aqueous solvents. The anion exchange resin can be used for the efficient removal of Cr(VI) from water and wastewater.

Synergistic extraction of Cr(VI) from Ni(II) and Co(II) by flat sheet supported liquid membranes using TIOA and TBP as carriers

“…The other acidic mediums for selective separation of Cr (VI) were not found as effective in present study. Especially in HCl media, some anionic or neutral Co(II) species like as CoCl 4 2-, CoCl 3 -, CoCl 2 can be formed in the feed phase. The formation adversly affects the selectivity of FSSLM process in terms of Cr(VI) over Co(II) and Ni(II), since these species can be extracted with both TIOA and TBP as well.…”

“…This result can be explained with the formation of anionic and neutral complexes of metals in chloride and sluphate media that these metal complexes occurs the adduct with TIOA and TBP in the FSSLM and feed phase interphase. Some anionic or neutral Co(II) species like as CoCl 4 2-, CoCl 3 -, CoCl 2 can be occurs in HCl media, at feed phase and they can be extracted by both TIOA and TBP from feed phase. This extraction adversly effects the selectivity of Cr (VI) over Co(II) through FSSLM process.…”

“…The acid concentration of the feed solution was adjusted by adding desired volume of concentrated H 2 SO 4 . The selection of mineral acid type in feed solution was tested with using HCl, HNO 3 and H 2 SO 4 . In present studies, we were used basic and neutral extractants with together.…”

“…On the other hand, some scientifi c studies noted that at higher concentration of Cr(III) may adversely effect the habitats 5-6 . Anionic Cr (VI) species, which are HCrO 4 -, CrO 4 2-, Cr 2 O 7 2-, are known as bioaccumulative and mutagenic due to their high mobility across cell membrane and their oxidizing potential on the biological molecules and structures 7 . Therefore, especially Cr(VI) must be eliminated from environmental sources to prevent its harmful effects on ecosystem.…”

Removal of Hexavalent Chromium from Water and Organic Solvent Mixed Media by Adsorption Using Weak Base Anion Exchanger Tulsion A-2X (MP)

“…Removal of Cr(VI) has become today a major concern due to its hazardous effects on health and environment such as high risk of lung cancer, damages to liver, kidney, nervous system and modification of DNA transcription [3,4]. Permissible limit for total chromium in water is 0.05 mg L -1 [5]. Proper treatment of chromium(VI) is very much essential prior discharge of chromium containing water into natural water sources.…”