Selective recovery of mercury by Procion Brown MX 5BR immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes

Adsorption of Cr(VI) onto PEI immobilized acrylate-based magnetic beads: Isotherms, kinetics and thermodynamics study

“…plexation, chemical precipitation, solvent extraction, reverse osmosis, ion exchange, filtration and membrane processes [6][7][8][9]. Among them, adsorption is one of more popular methods for the removal of chromium from the wastewaters.…”

Selective separation of mercury(II) using magnetic chitosan resin modified with Schiff's base derived from thiourea and glutaraldehyde

“…Chelating resins are easily regenerated from metal ions and they differ from activated carbon and ion exchange resins in their high selectivity in sorption processes [3]. Many articles that cover a vast number of different chelating resins were reported [4][5][6][7][8]. Recently, we reported on the use of different chelating resins with various functionalities for the selective separation of mercury [9][10][11][12].…”

Dynamic and equilibrium studies on adsorption of Cr(VI) ions onto binary bio-polymeric beads of cross linked alginate and gelatin

“…Thus, the removal of metal ions from dilute waste waters has become an important and widely studied research area where a number of technologies have been developed over the years [3]. The most important of these methods include filtration, chemical precipitation, ion exchange adsorption, electro deposition and membrane systems [4]. All these approaches have their inherent advantages and limitations.…”

“…CrO4 . It has been observed by Huang and Wu[35] that when Cr(VI) comes in contact with organic substances (such as gelatin or alginate in the present case) in acidic medium, a portion of Cr(VI) present in the solution is reduced to Cr(III) which may exist as following aqua complexes:Now, in the light of the above discussion the obtained results may be explained as below:(i) At the lowest pH value of the studied range, i.e.2.3, the suspension is highly acidic in nature and the bio-polymeric beads possess positively charged groups such as -NH + -and -NH 3 + , etc.…”