Simultaneous rejection of fluoride and Cr(VI) from synthetic fluoride-Cr(VI) binary water system by polyamide flat sheet reverse osmosis membrane and prediction of membrane performance by CFSK and CFSD models

Gaikwad, Mahendra S.; Balomajumder, Chandrajit

doi:10.1016/j.molliq.2017.03.073

Cited by 38 publications

(8 citation statements)

References 44 publications

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“…Chromium can be found in several oxidation forms ranging from Cr (II) to Cr (VI) Cr (VI) [2][3][4], among these states, Cr (III) and Cr (VI) are the most dominant and stable compounds. Even though both oxidants are interconnected and can form each other either by oxidation or reduction, the physical and chemical characteristics of both compounds are relatively opposite [5]. AsCr (III) is less mobile, stable, and nontoxic; Cr (VI) on the other hand, is reactive and toxic in excess concentrations and is responsible for developing various harmful diseases [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Temperature Impact on Reverse Osmosis Permeate Flux in the Remediation of Hexavalent Chromium

Shigidi

Anqi

Elkhaleefa

et al. 2021

Water

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Reverse osmosis technique was applied in removing hexavalent chromium ions from artificial wastewater. Different operating conditions were studied to monitor the separation process using commercial Reverse Osmosis BW30XFR membrane. Different concentrations of hexavalent chromium; 5, 30, and 100 ppm were tested. Samples were subjected to incrementally increasing operating pressure; 10, 30, and 45 bar and flow rates; 2.2, 3.4, and 4.5 L/min under various temperatures; 25, 35, 45, and 55 °C. Collected permeate and concentrations were measured after each experiment using a UV spectrophotometer. Results obtained presented a higher rejection percentage at lower feed concentrations with a value up to 99.8% for 5 ppm in comparison to 94.3% for 30 ppm and 77.2% for 100 ppm concentration due to concentration polarization; however, it showed no effect of increasing operating flow rates. Moreover, the increase in feed temperature from 25 to 55 °C had positively increased permeate flux to more than 300 times. The permeate flux at 25 °C is recorded for all tested samples in the range of 30 to 158 kg/h·m2, this range has risen at 55 °C under the same conditions to the range of 70 to 226 kg/h·m2, indicating alteration within the membrane pore size due to temperature increase and high applied pressure concluding high sensitivity of polymeric membranes towards changing permeate flow rate with increasing temperatures.

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Section: Introductionmentioning

confidence: 99%

Temperature Impact on Reverse Osmosis Permeate Flux in the Remediation of Hexavalent Chromium

Shigidi

Anqi

Elkhaleefa

et al. 2021

Water

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“…A polyamide reverse osmosis membrane was investigated for the removal of fluoride from a binary water mixture, contaminated with fluoride and chromium(VI) [70]. For a solution containing a mixture of 5 mg L −1 of both fluoride and hexavalent chromium and under optimum conditions of a pH of 8 and a pressure of 16 bar, the reverse osmosis membrane was able to achieve a 99.97% rejection for fluoride.…”

Section: Polymer Membranesmentioning

confidence: 99%

A Mini Review of Recent Findings in Cellulose-, Polymer- and Graphene-Based Membranes for Fluoride Removal from Drinking Water

Tolkou

Meez

Kyzas

et al. 2021

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Effective fluoride removal from water is a persistent global concern both for drinking water and wastewater treatment. According to World Health Organization (WHO), standards for the maximum contaminant level in drinking water cannot be higher than 1.5 mg F− L−1 since affects the skeletal and nervous systems of humans. Various technologies have been developed to decrease fluoride concentration from waters, such as adsorption, coagulation, precipitation and membrane separation. Membrane technology has been found to be a very effective technology, significantly reducing fluoride to desired standards levels; however, it has received less attention than other technologies because it is a costly process. This review aims to discuss the recent studies using modified membranes for fluoride removal. Emphasis is given on cellulose-, polymer- and graphene-based membranes and is further discussing the modification of membranes with several metals that have been developed in the last years. It was observed that the main focus of the total publications has been on the use of polymer-based membranes. Most of the membranes applied for defluoridation exhibit greater efficiency at pH values close to that of drinking water (i.e., 6–8), and maximum treatment capacity was obtained with the use of a cellulose modified membrane Fe-Al-Mn@chitosan with a permeate flux of 2000 L m−2 h−1, following the carbon-based amyloid fibril nano-ZrO2 composites (CAF-Zr) 1750 L m−2. A technical-economic comparison study of NF and RO is also referred, concluding that NF membrane is slightly less expensive.

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“…Therefore, producing a promising compound to remove Cd heavy metal is an important subject of interest. Several methods have been performed up to now to efficiently remove pollutants including electrochemical techniques (Baghban, Mehrabani-Zeinabad, & Moheb, 2014), ion exchange (Kołodyńska, Krukowska-Bąk, Kazmierczak-Razna, & Pietrzak, 2017), reverse osmosis (Gaikwad & Balomajumder, 2017), and adsorption (Biswas, Sarkar, Mandal, & Naidu, 2016). Among these techniques, the eco-friendly adsorption process is one of the most frequently applied methods because of its simplicity and cost-effectiveness (Alijani, Shariatinia, & Aroujalian Mashhadi, 2015).…”

Section: Introductionmentioning

confidence: 99%

Hybrid silica aerogel nanocomposite adsorbents designed for Cd(II) removal from aqueous solution

Shariatinia‬

Esmaeilzadeh

2019

Water Environment Research

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Hybrid silica aerogel (HSA) nanoparticles were synthesized by sol–gel method and drying at ambient pressure. Also, two magnetic nanocomposites of HSA with Fe3O4 nanoparticles and chitosan (CS) were prepared including HSA‐Fe3O4 and HSA‐Fe3O4‐CS. The morphology, structure, and magnetic properties of the HSA as well as its nanocomposites were analyzed by SEM, XRD, TGA, VSM, and ATR‐FTIR techniques. The saturation magnetization (Ms) values for the Fe3O4 NPs, HSA‐Fe3O4, and HSA‐Fe3O4‐CS nanocomposite film were 69.93, 19.04, and 5.77 emu/g, respectively. Furthermore, the abilities of the HSA, HSA‐Fe3O4, CS, and HSA‐Fe3O4‐CS adsorbents were assessed for removal of cadmium(II) heavy metal ions (100 ppm) from aqueous solution. All adsorbents removed/adsorbed the maximum Cd(II) ions in 120 min when adsorbent dosage = 20 mg and pH = 8. Moreover, the highest adsorption capacities were 58.5, 69.4, 65.8, and 71.9 mg/g for the HSA, CS, HSA‐Fe3O4, and HSA‐Fe3O4‐CS, respectively. Kinetic studies using all adsorbents verified that Cd(II) adsorption obeyed the second‐order model illustrating the analyte chemisorption was happened on the adsorbent surfaces. All adsorption data were well consistent with the Langmuir isotherms. The reusability experiment confirmed that all of adsorbents could preserve >95% of their initial adsorption capacities even after five series of adsorption/desorption tests. Practitioner points Hybrid silica aerogel (HSA), HSA‐Fe3O4, and HSA‐Fe3O4‐CS adsorbents were produced. Nanocomposites were characterized by XRD, TGA, SEM, VSM, and ATR‐FTIR analysis. Adsorption of cadmium(II) ions by adsorbents was examined in aqueous solution. The highest adsorption capacity was obtained for the HSA‐Fe3O4‐CS (71.9 mg/g). Cd(II) adsorption followed second‐order kinetics and Langmuir isotherm model.

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Simultaneous rejection of fluoride and Cr(VI) from synthetic fluoride-Cr(VI) binary water system by polyamide flat sheet reverse osmosis membrane and prediction of membrane performance by CFSK and CFSD models

Cited by 38 publications

References 44 publications

Temperature Impact on Reverse Osmosis Permeate Flux in the Remediation of Hexavalent Chromium

Temperature Impact on Reverse Osmosis Permeate Flux in the Remediation of Hexavalent Chromium

A Mini Review of Recent Findings in Cellulose-, Polymer- and Graphene-Based Membranes for Fluoride Removal from Drinking Water

Hybrid silica aerogel nanocomposite adsorbents designed for Cd(II) removal from aqueous solution

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