Cr(VI) Sorption from Aqueous Solution: A Review

Fenti, Angelo; Chianese, Simeone; Iovino, Pasquale; Musmarra, Dino; Salvestrini, Stefano

doi:10.3390/app10186477

Cited by 48 publications

(32 citation statements)

References 95 publications

(192 reference statements)

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“…This was due to the formation of hydrogen bonds between the groups in C-4-APD or C-2-APZ, which occupy the adsorption sites and make the actual maximum adsorption capacity lower than the calculated value. Furthermore, the large size of Cr2O7 2makes it difficult to enter the adsorption sites, thus limiting the adsorption capacity of Cr2O7 2-(Fenti et al 2020). These results demonstrate that the adsorption of Cr(VI) ions by C-4-APD and C-2-APZ was the monolayer adsorption process.…”

mentioning

confidence: 80%

Preparation of cotton fibers modified with aromatic heterocyclic compounds and study of Cr(VI) adsorption performance

Huang

Yin

et al. 2021

Cellulose

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In order to prepare low-cost and environmentally friendly adsorbent materials for adsorption of heavy metal ion, two kinds of novel modified cottons (C-4-APD and C-2-APZ) were obtained by introducing 4-aminopyridin and 2-aminopyrazine into the surface of degreasing cotton, respectively, and used for the removal of Cr(VI) ions from aqueous solution. The two modified cottons were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), which confirmed the amino groups, pyridine groups and pyrazine groups grafted onto the surface of modified cottons. The maximum adsorption capacities of C-4-APD and C-2-APZ were 73.78 mg/g and 61.34 mg/g, respectively, at the optimum pH of 6 and an initial concentration of 200 mg/g. Kinetic and isotherm studies were carried out to investigate the adsorption behavior of the modified cottons on Cr(VI) ions. The results showed that the adsorption of Cr(VI) ions by modified cottons followed a pseudo-second-order kinetic model, the equilibrium data were in good agreement with the Langmuir isotherm model, and electrostatic and chemisorption may be the main adsorption mechanisms. The recovery and reuse of modified cotton were achieved by washing with 2 wt% thiourea-hydrochloric acid solution (0.5 mol/L concentration of HCl), and the adsorption capacities of C-4-APD and C-2-APZ were maintained above 90% and 80%, respectively, after six cycles.

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confidence: 80%

Preparation of cotton fibers modified with aromatic heterocyclic compounds and study of Cr(VI) adsorption performance

Huang

Yin

et al. 2021

Cellulose

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“…Due to the negative net charge of Cr 6+ oxyanions, Cr 6+ adsorption is expected to involved electrostatic attraction or anion exchange with positively charged adsorbents sites. The uptake of Cr 6+ should be favored by a pH below the point of zero charge, which would impart the adsorbent a net positive charge (Fenti et al 2020).…”

Section: Adsorption Mechanisms Of Cr 6+ On Different Adsorbentsmentioning

confidence: 99%

“…It has been shown that the reduction reaction (conversion of Cr 6+ to Cr 3+ ) and electrostatic attraction are the main mechanisms of Cr 6+ adsorption on biochar and the reduction reaction had a higher contribution rate than the electrostatic attraction (Guo et al 2020). After conversion of Cr 6+ to Cr 3+ , the resulting Cr 3+ cations may be retained on the adsorbent sites by several mechanisms such as cation exchange, covalent binding, surface precipitation, and coprecipitation of Fe 3+ / Cr 3+ hydroxides (Fenti et al 2020).…”

Section: Adsorption Mechanisms Of Cr 6+ On Different Adsorbentsmentioning

confidence: 99%

The effects of chitosan composites on the immobilization of chromium in soil and marigold (Calendula officinalis) growth

Najafi

Golchin

Naidu

2021

Int. J. Environ. Sci. Technol.

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To study the effectiveness of various chitosan composites on the stabilization of Cr 6+ in contaminated soils and growth characteristics of the marigold plant, a factorial pot trial with completely randomized design and three replications was performed in controlled conditions. The experimental treatments were: the contamination levels of soil to Cr (0, 20, 60 and 180 mg/kg) and adsorbent types (pure chitosan, biochar, zeolite and manganese dioxide, composites of chitosan-biochar, chitosan-zeolite, chitosan-manganese dioxide and control). The results showed that increasing the concentration of Cr in the soil interfered with the processes of nutrient uptake by the marigold and led to a significant reduction in growth characteristics. But the addition of adsorbents to the soil by immobilizing some of the available Cr reduced marigold uptake of Cr and thus reduced its toxic effects. By adding adsorbents to the soil, marigold uptake of nutrients such as phosphorus, potassium and iron was improved, and growth indices increased. Among the adsorbents used in this experiment, the chitosan-manganese dioxide composite had a higher efficiency in the immobilization of Cr in the soil. By applying the chitosan-manganese dioxide composite to the soil at the rate of 0.5% W/W, the concentration of Cr in the shoot of the marigold plant decreased about 87.61% when compared to the control treatment. But the shoot height and shoot dry weight increased by 48.38 and 59.28%, and the concentration of phosphorus, potassium and iron in plant tissues increased by 100.00, 129.62 and 320.33%, respectively.

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“…Among the wide variety of pollutants, hexavalent chromium is by far one of the most toxic pollutants, representing the main threat to living organisms, including humans (Rowbotham et al, 2000). The most widely used strategy for the removal of Cr(VI) from polluted waters and wastewaters is sorption, because of its effectiveness, ease of use, low cost, and environmental sustainability (Fenti et al, 2020). In recent years, biochar has shown interesting properties mitigating the accumulation of hexavalent chromium (Xiao et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

Activated biochars derived from wood biomass liquefaction residues for effective removal of hazardous hexavalent chromium from aquatic environments

et al. 2021

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Residues obtained after wood biomass liquefaction were used as precursors for the synthesis of two activated biochars. The source of biomass liquefaction constituted of industrial wood processing by‐products, including bark and wood sawdust. The liquefied residues were analyzed in terms of chemical components and structure. Carbonization under nitrogen atmosphere followed by physical CO2 activation allowed to obtain microporous activated carbons with specific surface areas of 741 and 522 m2 g−1, and micropore volumes of 0.38 and 0.27 cm3 g−1, respectively. The obtained activated carbons were used to remove toxic hexavalent chromium from the aquatic environment. The observed sorption capacities were 80.6 mg g−1 versus 36.7 mg g−1 for wood bark‐derived and wood sawdust‐derived carbon, respectively, indicating a key role of the wood residue source in the effectiveness of Cr(VI) removal by resulting carbons. Despite the dominant microporous structure, the adsorption kinetics was surprisingly fast, especially for the bark‐derived carbon, since the adsorption equilibrium was reached within 2 h. The sorption mechanism of chromium was based on the carbon surface‐mediated reduction of toxic hexavalent form to its non‐toxic trivalent form, as confirmed by the X‐ray photoelectron analysis. Therefore, the residues from wood liquefaction can be easily converted into porous activated biocarbons capable of adsorbing significant amounts of hazardous Cr(VI) while reducing them to non‐toxic Cr(III).

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Cr(VI) Sorption from Aqueous Solution: A Review

Cited by 48 publications

References 95 publications

Preparation of cotton fibers modified with aromatic heterocyclic compounds and study of Cr(VI) adsorption performance

Preparation of cotton fibers modified with aromatic heterocyclic compounds and study of Cr(VI) adsorption performance

The effects of chitosan composites on the immobilization of chromium in soil and marigold (Calendula officinalis) growth

Activated biochars derived from wood biomass liquefaction residues for effective removal of hazardous hexavalent chromium from aquatic environments

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