Removal of hexavalent chromium by nanofiltration

Hafiane, Amor; Lemordant, Daniel; Dhahbi, Mahmoud

doi:10.1016/s0011-9164(00)00094-1

Cited by 161 publications

(81 citation statements)

References 14 publications

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“…In this case, retention coefficient increases with pH increase, but the effect is more pronounced for membranes with lower separation capacity (from 47 to 94.5% for Osmonics membranes) compared to more compact membranes (from 84 to 99.7% for Osmonics membranes) [25]. The dependence of the retention coefficient on the concentration of Cr in feed was also observed for NF membranes [25], but the range of the effect also depended on pH. In an acidic solution at higher concentrations of Cr in feed, higher retention was found, while at pH 6.5-11 the nature of this relationship was the opposite, i.e.…”

Section: Removal Of Anionic Micropollutantsmentioning

confidence: 88%

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Inorganic Micropollutants Removal by Means of Membrane Processes - State of the Art

Bodzek¹

2013

Ecological Chemistry and Engineering S

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A number of inorganic anions and metals, especially heavy metals, at certain conditions, have been found in potentially harmful concentrations in numerous water sources. The maximum permissible levels of these compounds, in drinking water and wastewaters discharged to environment, set by the WHO and a number of countries are very low (from µg/dm 3 to a few mg/dm 3 ). Several common treatment technologies, which are nowadays used for removal of inorganic contaminants from natural water supplies, represent serious exploitation problems. Membrane processes such as reverse osmosis and nanofiltration, ultrafiltration and microfiltration in integrated systems, Donnan dialysis and electrodialysis as well as membrane bioreactors, if properly selected, offer the advantage of producing high quality drinking water without inorganic substances as well as purified wastewater which can be drained off to natural water sources.

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Section: Removal Of Anionic Micropollutantsmentioning

confidence: 88%

“…Cr 2 O 7 2-ions are also present in the solution and their concentration depends on the initial concentration of the contaminant in the feed and pH. This ion is usually dominant at high concentrations of Cr and in strongly acidic environment (pH 1-7) but its concentration decreases with pH increase [1,2,25].…”

Section: Removal Of Anionic Micropollutantsmentioning

confidence: 99%

Inorganic Micropollutants Removal by Means of Membrane Processes - State of the Art

Bodzek¹

2013

Ecological Chemistry and Engineering S

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“…Solute separation in nanofiltration membrane involves mainly the electrostatic interaction of membrane and solutes on the membrane surface and size exclusion [18]. And the separation efficiency in a nanofiltration process gets influenced by parameters such as pH [19], concentration [20], applied transmembrane pressure [21], initial cross flow rate etc. The response surface methodology as an effective statistical method has recently been successfully applied to optimize complex processes by depicting the interaction relationship between response variables [22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Concentrating phenolic acids from Lonicera japonica by nanofiltration technology

Li¹,

Ma²,

Li³

et al. 2017

AIP Conference Proceedings

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ARTICLES YOU MAY BE INTERESTED INCrystallization of bovine insulin on a flow-free droplet-based platform AIP Conference Proceedings 1820, 030003 (2017) Abstract. Response surface analysis methodology was used to optimize the concentrate process of phenolic acids from Lonicera japonica by nanofiltration technique. On the basis of the influences of pressure, temperature and circulating volume, the retention rate of neochlorogenic acid, chlorogenic acid and 4-dicaffeoylquinic acid were selected as index, molecular weight cut-off of nanofiltration membrane, concentration and pH were selected as influencing factors during concentrate process. The experiment mathematical model was arranged according to Box-Behnken central composite experiment design. The optimal concentrate conditions were as following: nanofiltration molecular weight cut-off, 150 Da; solutes concentration, 18.34 μg/mL; pH, 4.26. The predicted value of retention rate was 97.99% under the optimum conditions, and the experimental value was 98.03±0.24%, which was in accordance with the predicted value. These results demonstrate that the combination of Box-Behnken design and response surface analysis can well optimize the concentrate process of Lonicera japonica water-extraction by nanofiltration, and the results provide the basis for nanofiltration concentrate for heat-sensitive traditional Chinese medicine.

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“…WHO and US-EPA have fixed 50 µg L -1 and 100 µg L -1 respectively of total chromium in drinking water [5]. Several methods, technologies, and materials used for removal of chromium are ion exchange [6], ultrafiltrartion [7], nanofiltration [8], Microbiological Treatment [9], oxidation [10], fly ash, zero-valent iron [11,12], activated carbon [13,14], Bentonite [15], agricultural wastes [16] washing with hot water [17], microorganisms [18]. However the most common industrial treatment process is based on reduction of hexavalent chromium into trivalent chromium by some reducing agent or by weak acid cation exchange resin followed by precipitation with ferric salt as Cr (OH) 3 and finally filtration [19].…”

Section: Introductionmentioning

confidence: 99%

An Efficient and Fast Process for the Removal of Trivalent and Hexavalent Chromium from Contaminated Water Using Zinc Peroxide Nanomaterial

Uppal¹,

Singh²

2015

Pharm Anal Acta

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Higher concentration of trivalent and hexavalent chromium (percent to mg L -1 ) can be effectively removed from water by adsorption or precipitation process, but difficult to remove lower concentration (<0.25 mg L -1 ) upto prescribed limits of World Health Organization (WHO) and United State-Environment Protection Agency (US-EPA). The lower concentration of chromium can be effectively removed using reverse osmosis system. In the proposed study we have successfully removed higher to lower concentration (20 to 0.1 mg L -1 ) of trivalent and hexavalent chromium using alone polyvinylpyrrolidone (PVP) functionalized zinc peroxide (ZnO 2 ) nanomaterial below detection limit (0.001 mg L -1 ) of Flame Atomic Absorption Spectrophotometer instrument (FAAS) within 15 minutes. The utilized nanomaterial alone act as oxidizing as well adsorbing agent, and purify water upto safe potability limits. The adsorption capacity of functionalized ZnO 2 nanomaterial for total chromium was found to be 4.98 mg g -1 which is much better than the several other materials reported in the literature for chromium removal. A process patent for the synthesis of varying sizes functionalized ZnO 2 nanomaterials has been granted in United State

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Removal of hexavalent chromium by nanofiltration

Cited by 161 publications

References 14 publications

Inorganic Micropollutants Removal by Means of Membrane Processes - State of the Art

Inorganic Micropollutants Removal by Means of Membrane Processes - State of the Art

Concentrating phenolic acids from Lonicera japonica by nanofiltration technology

An Efficient and Fast Process for the Removal of Trivalent and Hexavalent Chromium from Contaminated Water Using Zinc Peroxide Nanomaterial

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