Performance of commercial nanofiltration membranes in the removal of nitrate ions

Santafé-Moros, Asunción; Gozálvez-Zafrilla, José M.; Lora-García, Jaime

doi:10.1016/j.desal.2005.02.080

Cited by 70 publications

(47 citation statements)

References 16 publications

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“…Fig. 2(a) showed adsorption isotherm for NO 3 − at temperature of 10, 25 and 35 • C. The result showed that HT3(Pd/Cu) catalyst possessed apparent adsorption capacity for NO 3 − , especially at 25 and 35 • C, which could be explained by considering the capacity of hydrotalcite to concentrate anions in the interlayer space. Although the specific surface area of the regenerated hydrotalcite was very low, nitrate ions could be concentrated by ionic forces between the layers.…”

Section: The Effect Of Temperaturementioning

confidence: 84%

“…It was discovered that, at different temperature, adsorption isotherm for NO 3 − fit well with Langmuir's equation …”

Section: The Effect Of Temperaturementioning

confidence: 99%

“…1. As TG analysis revealed, gradual weight loss was observed from about 50 • C to approximately 600 • C, with two main endothermic effects at about 173 and 410 • C. The first large endothermic effect at about 173 • C involved interlayer water loss [20]; the second endothermic effect at 410 • C accounted for hydrotalcite decomposition which was accompanied by dehydroxylation and the decomposition of CO 3 2− in the brucite-like layers [20]. Carbon dioxide evolution induced the formation of pores, which was the reason for the drastic increase in the specific surface area.…”

Section: Characterization Of Catalystmentioning

confidence: 99%

“…The most environmental friendly methods for nitrate removal, based on selective reduction of nitrate to nitrogen, are biological digestion [5,6] and catalytic reduction [7,8]. The biological denitrification process is currently the most widely used, however, possible bacterial contamination, the presence of residual organics and the possible increase in chlorine demand in purified water [3] limit the application of this process.…”

Section: Introductionmentioning

confidence: 99%

“…causing cancer and nethemoglobinemia) [1,2]. Conventional physicochemical methods, including ionexchange, reverse osmosis and electrodialysis [3,4], allow effective removal of nitrate ions from water by concentrating them in a secondary waste stream, but do not generally achieve their complete disposal. The most environmental friendly methods for nitrate removal, based on selective reduction of nitrate to nitrogen, are biological digestion [5,6] and catalytic reduction [7,8].…”

Section: Introductionmentioning

confidence: 99%

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Effect of liquid property on adsorption and catalytic reduction of nitrate over hydrotalcite-supported Pd-Cu catalyst

Wang

Liu

2007

Journal of Molecular Catalysis A: Chemical

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This study focused on investigating the effect of liquid property on adsorption and catalytic reduction of nitrate over hydrotalcite-supported Pd-Cu catalyst. Batch experiments were conducted under specific operating conditions. It was found that nitrate ions were adsorbed apparently by hydrotalcite-supported Pd-Cu catalyst at different reaction temperature (10, 25 and 35• C). Adsorption isotherms for NO 3 − were described by Langmuir's equation. Higher reaction temperature accelerated nitrate adsorption and reduction, and simultaneously decreased the accumulation of NO 2 − and NH 4 + . Nitrate adsorption and reduction were independent of the initial pH because of the high buffering capacity of hydrotalcite when the initial pH of solution was from 5.25 to 7.4. However, the dissolve of hydrotalcite-supported Pd-Cu catalyst at low initial pH (3.77) and higher concentration of OH − ions at high initial pH (10.74) decreased nitrate adsorption and reduction. When using various nitrate salts as a source of nitrate ions, nitrate adsorption and reduction removal efficiency decreased in the order: Fe 3+ > Mn 2+ > Mg 2+ > Ca 2+ > Na + , which was attributed to different affinity toward OH − . Co-existed cations in water with higher valence and lower crystal ionic radius and solubility constant of hydroxide showed stronger affinity toward OH − and consequently increased the concentration of active sites accessible to NO 3 − and NO 2 − . The competitive adsorption of Cl − , SO 4 2− and HCO 3 − with nitrate on the catalyst surface suppressed the adsorption and reduction of NO 3 − . Besides, few metals dissolved in neutral and alkaline solution. The activity of the hydrotalcite-supported Pd-Cu catalyst for nitrate reduction kept steady after repeated use.

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Section: The Effect Of Temperaturementioning

confidence: 84%

“…It was discovered that, at different temperature, adsorption isotherm for NO 3 − fit well with Langmuir's equation …”

Section: The Effect Of Temperaturementioning

confidence: 99%

Section: Characterization Of Catalystmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effect of liquid property on adsorption and catalytic reduction of nitrate over hydrotalcite-supported Pd-Cu catalyst

Wang

Liu

2007

Journal of Molecular Catalysis A: Chemical

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Nanofiltration – Theory and Application

Bellona

2014

Desalination

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Nanofi ltration (NF) represents a relatively recent development in membrane technology with characteristics that fall between ultrafi ltration (UF) and reverse osmosis (RO). NF membranes capable of ion and small uncharged solute separation (i.e., loose NF) represent a unique membrane process that can be used for a variety of applications. With effective pore sizes in the range of 1 nm, solute removal is believed to be a function of steric hindrance, and Donnan and dielectric exclusion which, allows for manipulation of the NF process to achieve preferential removal of multi-valent ions, separation of uncharged solutes based on size, and demineralization of process streams containing valuable constituents. Signifi cant recent interest in the use of NF for a wide variety of separation processes indicates that further membrane development will lead to increased use of NF in the near future. This chapter provides an overview of NF technology including history, theory and application.

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Nanofiltration – Theory and Application

Bellona

2019

Desalination

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Performance of commercial nanofiltration membranes in the removal of nitrate ions

Cited by 70 publications

References 16 publications

Effect of liquid property on adsorption and catalytic reduction of nitrate over hydrotalcite-supported Pd-Cu catalyst

Effect of liquid property on adsorption and catalytic reduction of nitrate over hydrotalcite-supported Pd-Cu catalyst

Nanofiltration – Theory and Application

Nanofiltration – Theory and Application

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