Recent innovative research on chromium (VI) adsorption mechanism

Islam, Md. Aminul; Angove, Michael J.; Morton, David W.

doi:10.1016/j.enmm.2019.100267

Cited by 70 publications

(35 citation statements)

References 177 publications

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“…The results in Table 1 show that the adsorption capacity of CNP is somewhat higher than that of CNP PEI. To understand this trend, a detailed surface evaluation is further conducted, since surface functionality is expected to play a vital role in the removal of Cr (VI) [1,16,23,28,37,43]. The surface functional groups are known to attract chromium species to the carbon surface, where they can be further stored inside the carbon's pores.…”

Section: Resultsmentioning

confidence: 99%

“…Thus, modification of activated carbon surface with long-chained nitrogen-containing polymer-polyethylenimine (PEI)-presents a viable perspective to improve the removal efficiency of carbon for chromium. Although limited data are published on Cr (VI) removal on activated carbons with PEI [41,42], the latter one was suggested to enhance the positive charge density of the carbon surface [36,41], which in turn can significantly increase the electrostatic affinity of Cr (VI), mostly present in solution as an anion [14,15,22,23,[27][28][29][30][31]37,41,43].…”

Section: Introductionmentioning

confidence: 99%

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The Role of Surface Chemistry and Polyethylenimine Grafting in the Removal of Cr (VI) by Activated Carbons from Cashew Nut Shells

Smith

Rivera

Bello

et al. 2021

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Activated carbons prepared from cashew nut shells and modified by grafting polyethylenimine onto the surface were tested for removal of Cr (VI). The removal efficiency of carbons without and with polyethylenimine decreased with an increase in pH, with maximum efficiency found at pH 2. The average maximum adsorption capacities of carbons were calculated to be 340 ± 20 mg/g and 320 ± 20 mg/g for unmodified and modified carbons, respectively. Surface characterization of carbons revealed that C–O functionalities are actively involved in both polyethylenimine grafting and Cr (VI) removal. Moreover, lactone groups and amides, formed by polyethylenimine grafting, seemingly undergo acid hydrolysis with formation of phenol and carboxylic groups. Considering that Cr (III) is the only form of chromium found on the surface of both carbons, the reduction mechanism is deduced as the predominant one. Here Cr (VI), majorly present as HCrO4¯, is attracted to the positively charged carbon surface, reduced to Cr (III) by phenol groups, and adsorbed inside the pores. The mechanism of Cr (VI) removal appears to be similar for unmodified and modified carbons, where the smaller adsorption capacity of the latter one can be related to steric hindrance and pore inaccessibility.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Role of Surface Chemistry and Polyethylenimine Grafting in the Removal of Cr (VI) by Activated Carbons from Cashew Nut Shells

Smith

Rivera

Bello

et al. 2021

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“…The mechanism suggested three main steps for the capture of Cr (VI) ions from the bulk phase to the solid phase. Thus, the first step implicated the rapid adsorption of the Cr (VI) ions on these functional sites on the PSh surface by electrostatic attraction, following a surface protonation of PSh sites (Islam et al 2019). Moreover, surface complexation facilitated the Cr (VI) ions uptake by the PSh sorbent owing to the presence of carboxyl groups.…”

Section: Mechanism Of the Biosorption Of Cr (Vi) On Pshmentioning

confidence: 99%

“…Lastly, the reduced Cr (III) was more efficiently attracted to functional sites by electrostatic attractions and surface complexation. The greater affinity of Cr (III) ions for active anionic sites on the surface of the PSh improved the anchoring of chromium ions on the PSh biosorbent (Islam et al 2019).…”

Section: Mechanism Of the Biosorption Of Cr (Vi) On Pshmentioning

confidence: 99%

Modelling and optimization of hexavalent chromium removal from aqueous solution by adsorption on low-cost agricultural waste biomass using response surface methodological approach

Rzig

Guesmi

Hamrouni

2021

Water Science and Technology

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In this study, response surface methodology (RSM) approach using central composite design (CCD) was investigated to develop mathematical model and to optimize the effects of pH, adsorbent amount and temperature related to the hexavalent chromium removal by biosorption on peanut shells (PSh). The highest removal percentage of 30.28% was found by the predicted model under the optimum conditions (pH of 2.11, 0.73 g of PSh and 37.2 °C) for a 100 mg/L initial Cr (VI) concentration, which was very near to the experimental value (29.92%). The PSh was characterized by SEM, EDX, FTIR, BET, XRD analysis. Moreover, Langmuir isotherm fitted well (R2 = 0.992) with the experimental data, and the maximum adsorption capacity was discovered to be 2.48 and 3.49 mg/g respectively at 25 and 45 °C. Kinetic data was well foreseen by pseudo second order. Thermodynamic study depicted that biosorption of Cr(VI) onto PSh was spontaneous and endothermic. Regeneration of the PSh using NaOH showed a loss <5% in the Cr (VI) removal efficiency till three recycle runs. In summary, the Cr (VI) removal onto economic, sensitive and selective biosorbent (PSh) optimized using CCD to study biosorption behaviors.

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“…Cr(VI) is an extremely toxic chromium species that is known to cause severe environmental and health problems [21] to human, animal, and aquatic life systems. Such adverse health effects of Cr(VI) include contact dermatitis, lung carcinoma, diarrhoea, ulcers, kidney failure, liver damage, and other diseases of the gastrointestinal organs [3,[22][23][24][25]. Not only is Cr(VI) highly carcinogenic and mutagenic, it is also known to cause birth defects [3].…”

Section: Introductionmentioning

confidence: 99%

Interactive Relationship between Cementitious Materials and Acid Mine Drainage: Their Effects on Chromium Cr(VI) Removal

Shabalala

Basitere

2020

Minerals

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Elevated hexavalent chromium (Cr(VI)) levels in pervious concrete may undermine its successful application in water treatment. Portland cement CEM I 52.5R (CEM I), coal fly ash (FA), natural zeolite and ground granulated blast-furnace slag (GGBS) were evaluated as adsorbents for removal of Cr(VI) from acid mine drainage (AMD). Adsorption experiments were conducted at dosages of 6, 10, 30 and 60 g of adsorbent in 200 mL of AMD, while the mixing contact time was varied from 15 to 300 min. It was found that the use of CEM1 and FA adsorbents strongly increased the Cr(VI) concentration in AMD. Conversely, zeolite and GGBS removed up to 76% and 100% of Cr(VI) from AMD, respectively, upon their use at dosages of at least 10 g of the adsorbent. Freundlich isotherm was found better fitted with a high correlation coefficient (R2 = 0.998 for zeolite and 0.973 for GGBS) than to the Langmuir model (R2 = 0.965 for zeolite and 0.955 for GGBS). Adsorption and ion exchange seem to be active mechanisms for the Cr(VI) removal. These results suggest that zeolite and GGBS can be considered as partial cement replacement materials for effective reduction or removal of Cr(VI) from the treated water.

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Recent innovative research on chromium (VI) adsorption mechanism

Cited by 70 publications

References 177 publications

The Role of Surface Chemistry and Polyethylenimine Grafting in the Removal of Cr (VI) by Activated Carbons from Cashew Nut Shells

The Role of Surface Chemistry and Polyethylenimine Grafting in the Removal of Cr (VI) by Activated Carbons from Cashew Nut Shells

Modelling and optimization of hexavalent chromium removal from aqueous solution by adsorption on low-cost agricultural waste biomass using response surface methodological approach

Interactive Relationship between Cementitious Materials and Acid Mine Drainage: Their Effects on Chromium Cr(VI) Removal

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