Fast removal of Co(ii) from aqueous solution using porous carboxymethyl chitosan beads and its adsorption mechanism

Abstract

Porous carboxymethyl chitosan (PCMC) beads were synthesized via ionic coacervation/chemical crosslinking, using polyethylene glycol (PEG) as a porogen and calcium chloride and glutaraldehyde as physical and chemical cross-linkers. The as-synthesized PCMC beads were characterized using SEM, EDS, BET, TGA, FTIR and XPS analysis and then tested for the removal of Co(II) from aqueous solution. The effects of the initial pH, Co(II) concentration and temperature were investigated. It was found that the adsorption equilibrium is reached within 6 h and the maximum adsorption capacity is 46.25 mg g À1 .In addition, the kinetics and equilibrium data are well described by pseudo-second-order kinetics and the Langmuir isotherm model. Moreover, the desorption and re-adsorption performance was also studied, and the results revealed that the prepared new adsorbent still showed good adsorption performance after five cycles of regeneration. Finally, the adsorption mechanism, including chemical and physical adsorption, was proposed on the basis of the microstructure analysis, adsorption kinetics and isotherm results, and chemical adsorption was found to be the main adsorption mechanism during the process of the removal of Co(II).

Sorption capacity of seaweed-like sodium titanate mats for Co2+ removal

“…Previously, researchers studied the sorbents for Co 2+ removal, such as sodium titanates, zeolites, hydroxyapatite, and clay minerals. [4][5][6][7][8][9][10][11][12][13] In comparison with past reports, among the adsorbents composed of inorganic materials, SST has shown a relatively high sorption capacity for Co 2+ . There are two possible reasons why the sorption capacity of SST was higher than TC.…”

“…2,3 In recent years, some organic or inorganic materials have been proposed as adsorbents for Co 2+ removal from wastewater. [4][5][6][7][8][9][10][11][12][13] Furthermore, several heavy metals and radionuclides can be removed using inorganic ion exchangers. 14 Sodium titanate compounds are used as a purication material for the removal of heavy metal ions and radionuclides from industrial wastewater.…”

Effect of Active Site Modification towards Performance Enhancement in Biopolymer κ-Carrageenan Derivatives

“…The pattern of current research focuses on biopolymer polysaccharides as sensors, polymer electrolytes, and biological applications through the enhancement of active sites such as cellulose, chitosan, and carrageenan [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Modification of active sites in a biopolymer polysaccharide structure is vital for the enhancement of the polysaccharide’s performance.…”

“…Meanwhile, Luo et al [ 2 ] reported that carboxymethyl chitosan increased the adsorption of heavy metal ions compared to pristine chitosan. In 2014 and 2017, Wang et al [ 5 , 7 ] modified Artemisia sphaerocephala polysaccharide by substituting the active site with a sulfate group with a higher electronegative atom.…”

Functionalized graphene oxide/carboxymethyl chitosan composite aerogels with strong compressive strength for water purification

“…In fact, CMC presents good reusability and good adsorption capacity for heavy metal ions through crosslinking 26–28 . Furthermore, CMC can be employed in as nanoparticles or beads in heavy metal recovery 29–30 . Meanwhile, CMC composites present different types of polymers, with a second component widely applied in wastewater treatment 31–33 .…”