PREPARATION AND EVALUATION OF MAGNETIC CHITOSAN PARTICLES MODIFIED WITH ETHYLENEDIAMINE AND Fe(III) FOR THE REMOVAL OF Cr(VI) FROM AQUEOUS SOLUTIONS

“…-Brazil and was derived from crustacean skeleton chitin, with 5.60 × 10 −3 mol of amino groups per gram of biopolymer, 90% degree of deacetylation, 80 mesh grain size, pH 7.50 and density of 0.38 g mL −1 . The chitosan used in this study have a point of zero charge (pH pzc ) at pH 6.30 as described by Toledo et al [13].…”

Section: Chitosanmentioning

confidence: 99%

“…Equation 12 in which qe/Ce is the equilibrium constant obtained during temperature variation (mol g −1 ), T is the temperature (K) and Rg is the universal gas constant (8.314 J mol −1 K −1 ). On a graph of ln qe/Ce vs. (1/T ), a line through the slope and intercept allows the calculation of entropy and enthalpy, with these values, Gibbs free energy is calculated using Equation (13).…”

Section: Adsorption Isothermsmentioning

confidence: 99%

Saccharomyces cerevisiaeimmobilized onto cross-linked chitosan beads: application of a novel material for the removal of dye toxicity

Dilarri

Corso

2017

Environmental Technology

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Waste from textile industries can severely harm the environment. Dyes are the main residues of these effluents. Saccharomyces cerevisiae is already known to be an efficient adsorbent for the removal of dyes. However, the lack of applicability and limitation of the use of cell biomass in an industrial treatment makes it impossible to apply them. Thus the aim of this work was to immobilize S. cerevisiae in cross-linked chitosan beads by two different techniques (contact immobilization and encapsulation in the polymer matrix), proposing two new materials for adsorption. Adsorption experiments were carried out to analyse the kinetics, isotherm and thermodynamics adsorptive of the synthesized materials. The adsorption data obtained were compared with the S. cerevisiae biomass and with the cell-free cross-linked chitosan beads to evaluate the efficiency of the two synthesized materials. The Fourier transform infrared spectrophotometer was used to characterize and analyse the main adsorption sites of the tested materials. Bioassays using the microcrustacean Daphnia similis verified if the materials could reduce the toxicity of the medium after its application in the treatment. Both materials synthesized in this work can potentially remove dyes from effluents, in addition to being able to significantly decrease dye toxicity from an aqueous medium.

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“…In their experiments, in basic solution (pH > 7), the protonation of amine groups was reduced and the concentration of hydroxyl groups (OH -) increased which creates a negative surface charge on chitosan beads. That leads to produce a repulsive interaction between CrO 4 2ions and chitosan beads, which decreases the adsorption capacity of Cr(VI) in basic solution [54,63].…”

Section: Characterization Of Chitosan Beadsmentioning

confidence: 99%

“…Due to the presence of amino (-NH 2 ) and hydroxyl (-OH) groups in its structure, chitosan is capable to adsorb heavy metals from aqueous solution by creating an electronic bond between these active sites and metal ions [51,52]. In addition, chitosan has been investigated by many studies as an excellent material for heavy metal adsorption such as cadmium and copper [28], arsenic [41], and chromium and zinc [53,54,55,56].…”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of bioadsorbent beads for removing selected heavy metal ions from wastewater

Salih¹

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Rapid industrialization is one of the major threats to water pollution worldwide, as discharge effluents contain large amounts of toxic metal ions. Heavy metals are highly toxic to the ecosystem and human even at very low concentrations. We focused on easily available, green and eco-friendly with low operational cost materials to remove heavy metals from industrial wastewater. Chitosan is considered an alternative and sustainable adsorbent due to its highly efficient adsorption capacities for heavy metals. In this particular study, chitosan was successfully modified by using diatomaceous earth and then fabricated as spherical beads using the drop-wise method. Pristine chitosan (CS) beads and chitosan coated diatomaceous earth (CSDE) beads were used to remove zinc, chromium, lead, and nickel ions from aqueous solutions in batch and continuous adsorption processes. The prepared adsorbents were characterized by using scanning electron microscopy (SEM) B Brunauer-Emmett-Teller (BET), Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and zeta potential. The results showed that the prepared adsorbents were porous in nature and the total surface area were increased from 1.9 m2/g for pristine chitosan to 14.4 m2/g for chitosan coated diatomaceous earth. The performance of prepared adsorbents was investigated at different temperatures, initial pH of the solution, contact times, initial metal concentrations. The pseudo-second-order kinetic model is more likely to predict the kinetic behavior of the metal ions adsorption process for the whole used contact time range, and the adsorption isotherm data of CS and CSDE beads were well fitted to Langmuir model. The maximal adsorption capacities of prepared CSDE beads were found to be pH dependent as follows: - Zinc ion - 127.4 mg/g at initial Zn(II) concentration 500 mg/L and pH 6. - Chromium ion - 84.23 mg/g at initial Cr(VI) concentration 1000 mg/L and pH 3. - Lead ion - 175.22 mg/g at initial Pb(II) concentration 400 mg/L and pH 7. - Nickel ion - 149.64 mg/g at initial Ni(II) concentration 400 mg/L and pH 6. Successful desorption and regeneration of prepared adsorbents were achieved (with common chemicals) and possessed excellent reusability (up to 10 cycles without a significant loss in adsorption capacity). The common anions and cations coexisting ions have insignificant impact on the removal capacity of prepared adsorbents. Overall, these results suggest that the environmentally friendly materials might be recognized as effective adsorbent and sustainable means for the separation of heavy metals from wastewater streams. That will lead to a new solution to water pollution required in the modern industrial society.

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PREPARATION AND EVALUATION OF MAGNETIC CHITOSAN PARTICLES MODIFIED WITH ETHYLENEDIAMINE AND Fe(III) FOR THE REMOVAL OF Cr(VI) FROM AQUEOUS SOLUTIONS

Cited by 4 publications

References 0 publications

A new 3D cobalt (II) metal–organic framework nanostructure for heavy metal adsorption

A new 3D cobalt (II) metal–organic framework nanostructure for heavy metal adsorption

Saccharomyces cerevisiaeimmobilized onto cross-linked chitosan beads: application of a novel material for the removal of dye toxicity

Preparation and characterization of bioadsorbent beads for removing selected heavy metal ions from wastewater

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