in this research, chitosan was used for the removal of cr (vi) ions from aqueous solution. the effect of parameters like solution ph, initial cr (vi) concentration, agitation time, amount of adsorbent and agitation speed on the adsorption process was studied. the experimental equilibrium data were analyzed by using various models such as langmuir and freundlich. freundlich isotherm model fitted...

The aim of this study was to evaluate the adsorption capacity of the novel coated activated carbon by chitosan for removal of Cr (VI) and Cd (II) ions from single and bi-solute dilute aqueous solutions. In addition, the adsorption abilities of activated carbon (AC), chitosan (CH) and chitosan / activated carbon composite (CHAC) have been compared. Adsorption studies were performed in a batch sy...

The adsorption ability of Dowex Optipore L493 resin modified with Aliquat 336 (MR), activated carbon modified with Aliquat 336 (MAC) and sawdust modified with Aliquat 336 (MS) for removal of Cr(VI) from aqueous solution in batch system was investigated. The effects of operational parameters such as adsorbent dosage, initial concentration of Cr(VI) ions, pH, temperature and contact time were stu...

−Cross-linked chitosan/bentonite composite (CCB) was prepared, and characterized by Fourier transform infrared (FTIR) spectroscopy, BET surface area and pore diameter analyses, X-ray diffraction (XRD) patterns and thermal gravimetric analyses (TGA). The adsorption of hexavalent chromium Cr(VI) onto CCB as a function of adsorbent dosage, initial Cr(VI) concentration, solution pH, and contact tim...

The present study reports the use of raw, iron oxide, and aluminum oxide impregnated carbon nanotubes (CNTs) for the adsorption of hexavalent chromium (Cr(VI)) ions from aqueous solution. The raw CNTs were impregnated with 1% and 10% loadings (weight %) of iron oxide and aluminum oxide nanoparticles using wet impregnation technique. The synthesized materials were characterized using scanning el...

Modification of chitosan biopolymer was achieved by grafting (3-phenyl-1H-pyrazole-4-carbaldehyde) by the Schiff base reaction to synthesize a new chitosan derivative (ChD). The formation of the product was confirmed by FTIR, XRD and CNMR analysis. The grafted molecule provided additional nitrogen bearing groups as binding sites. The new derivative was used to investigate the removal of Cr (VI)...

This work describes the synthesis of a novel magnetic graphene oxide composite for removal of Cr(VI) ions. The synthesized nanosorbent were characterized with various techniques such as FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), elemental analysis and vibrating sample magnetometry (VSM). This material is illustrated to represent a viable sorbent for the removal of Cr(VI...

Arthrobacter viscosus biomass was used for Cr(VI) biosorption. The effect of pH on Cr(VI) reduction and removal from aqueous solution was studied in the range of 1-4. The Cr(VI) removal involves both redox reaction and adsorption of metal ions on biomass surface. The removal rate of Cr(VI) was enhanced by very acid conditions, while higher solution pH values favored the removal of total chromiu...

This paper reports the evaluation of adsorbing Cr (VI) ions on sorbent prepared from chitosan (CHT), a versatile derivative of chitin, and dodecyl amine modified locally available kaolinite clay (Bijoypur clay) (MC) that has excellent mechanical properties and great resistance to chemical and biological attack. The effect of the initial metal ion concentration, solution pH, contact time, and ad...