Catalytic removal of nitrates from waters in a continuous flow process: The remarkable effect of liquid flow rate and gas feed composition

Theologides, Christodoulos P.; Savva, Petros G.; Costa, Costas N.

doi:10.1016/j.apcatb.2010.11.024

Cited by 32 publications

(21 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This fact was later confirmed by Theologides et al [48,113], who concluded that the production of ammonium could be decreased by up to three times when 20 vol% of air is added to the gas fed to the fixed bed catalytic reactor.…”

Section: Continuous Reactorsmentioning

confidence: 73%

“…However, further implementation of the process will require the analysis of continuous operation and process scale-up. Fixed bed [9,41,48,57,66] and trickle-bed [55,67] continuous reactors have been successfully tested in catalytic experiments to remove nitrates from water. For instance, the behaviour of Pd-In bimetallic alumina catalyst in a fixed bed reactor to carry out water denitrification was studied by Mendow et al [57].…”

Section: Continuous Reactorsmentioning

confidence: 99%

See 1 more Smart Citation

State-of-the-art and perspectives of the catalytic and electrocatalytic reduction of aqueous nitrates

Martínez

Ortiz

Ortíz

2017

Applied Catalysis B: Environmental

425

280

View full text Add to dashboard Cite

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. State-of-the-art and perspectives of the catalytic and electrocatalytic reduction of aqueous nitrates.

show abstract

Section: Continuous Reactorsmentioning

confidence: 73%

Section: Continuous Reactorsmentioning

confidence: 99%

State-of-the-art and perspectives of the catalytic and electrocatalytic reduction of aqueous nitrates

Martínez

Ortiz

Ortíz

2017

Applied Catalysis B: Environmental

425

280

View full text Add to dashboard Cite

show abstract

“…At present, we are attempting to control the production of ammonium by various means, such as the addition of a small amount of oxygen into the dilute H 2 gas, that have been reported to have the effect of reducing ammonium production [15].…”

Section: Resultsmentioning

confidence: 99%

Catalytic Hydrogenation of Nitrate in Water Using a Pd–Cu/Al2O3 Catalyst and Dilute H2 Microbubbles

Nakayama

Takahashi

2015

Catal Lett

View full text Add to dashboard Cite

The catalytic hydrogenation of nitrate was performed in solutions containing 20 mg/dm 3 NO À 3 using a PdCu/Al 2 O 3 catalyst (synthesized with a Cu/Pd ratio of 0.25) together with microbubbles (radii \50 lm) of 9.4-43.7 % H 2 in N 2 . Significant enhancement of the hydrogenation rate was observed due to the application of the microbubbles. The nitrate conversion factors for microbubble hydrogenation were approximately 1.7-3.8 times greater than those obtained using conventional macrobubbles (radii [1500 lm). The application of microbubbles was also effective during hydrogenation in a more concentrated nitrate solution containing 77 mg/dm 3 NO À 3 . Graphical Abstract

show abstract

“…The use of a special flow apparatus that is suitable for three-phase catalytic experiments (solid-liquid-gas) was necessary for the implementation of the catalytic studies in this work [24]. Catalytic experiments were conducted in a custom-made autoclave CSTR reactor (Autoclave Engineers, USA, and PIF Eng&Tech., Spain) equipped with a Mahoney-Robinson catalyst basket (200 mL).…”

Section: Apparatusmentioning

confidence: 99%

Catalytic removal of pharmaceutical compounds in water medium under an H2 stream over various metal-supported catalysts: A promising process

Pantelidou

Theologides

Savva

et al. 2015

Desalination and Water Treatment

Self Cite

View full text Add to dashboard Cite

A B S T R A C TTo date, very few prescriptive studies have been reported in the literature concerning the catalytic removal of pharmaceutical substances in wastewater using H 2 in the presence of O 2 for the in situ formation of H 2 O 2 , while the mechanism of the reaction has not been studied in detail yet. Hydrogen peroxide is a potent oxidizing agent used extensively in catalytic wet air oxidation (CWAO) applications and can be used for the elimination of pharmaceuticals from waste water. In the present work, an attempt has been made to elucidate the actual effects of the in situ production of hydrogen peroxide on the CWAO of pharmaceuticals. Therefore, the effects of the nature of the active phase (Pd, Pt, and Rh), as well as the feed gas composition have been examined toward the reaction at hand. The results showed that 1% Pd/Al 2 O 3 and 1% Rh/Al 2 O 3 are the most effective catalysts for the elimination of paracetamol from the reaction medium using hydrogen-rich streams, having a conversion of up to 70% in 2 h. A maximum conversion of paracetamol of 90% was obtained in just 30 min of reaction over 1 wt.% Rh/Al 2 O 3 , when using pure hydrogen in the feed. Total organic carbon measurements performed over the latter catalyst showed that practically no organic carbon is removed from the liquid phase, indicating the conversion of paracetamol to a different organic (probably aromatic) compound, through hydrogenation. Toxicity tests that followed showed a dramatic decrease in the toxicity of the products solution, indicating that paracetamol hydrogenation might be a promising method for the elimination of its toxicity.

show abstract

Catalytic removal of nitrates from waters in a continuous flow process: The remarkable effect of liquid flow rate and gas feed composition

Cited by 32 publications

References 35 publications

State-of-the-art and perspectives of the catalytic and electrocatalytic reduction of aqueous nitrates

State-of-the-art and perspectives of the catalytic and electrocatalytic reduction of aqueous nitrates

Catalytic Hydrogenation of Nitrate in Water Using a Pd–Cu/Al2O3 Catalyst and Dilute H2 Microbubbles

Catalytic removal of pharmaceutical compounds in water medium under an H2 stream over various metal-supported catalysts: A promising process

Contact Info

Product

Resources

About