Low-temperature conversion of ammonia to nitrogen in water with ozone over composite metal oxide catalyst

Chen, Yunnen; Wu, Ye Fan; Liu, Chen; Lin, Guiping; Nie, Jun; Chen, Yu; Qiu, Tingsheng

doi:10.1016/j.jes.2017.04.032

Cited by 40 publications

(11 citation statements)

References 23 publications

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“…Two mechanisms were proposed: 1) ammonia nitrogen was directly oxidized with ozone on the hydroxylated surface of MgO and 2) both ammonia nitrogen and ozone were adsorbed and subsequently reacted on the surface of MgO (Figure 7). Similar to Chen et al [23] it was not mentioned the dissolution behavior of MgO into the reaction solution during the reaction.…”

Section: Heterogeneous Catalysis Over Mgomentioning

confidence: 83%

“…Chen et al reported that a composite containing Co3O4 and MgO (Mg:Co = 4:1) was a more active catalyst than pristine Co3O4 under mild-alkaline conditions and worked even at room temperature as reported in [23]. It was proposed that under alkaline conditions, ozone first gave OH by the reaction with OH -(Equations 9-11) which further oxidized NH3 into N2 and NO3 -(Equations 12-15).…”

Section: Heterogeneous Catalysis Over Mgomentioning

confidence: 96%

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Oxidation of Ammonia Nitrogen with Ozone in Water: A Mini Review

et al. 2020

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Since ammonia nitrogen is a pollutant causing eutrophication, it must be removed from wastewater to develop sustainable environment and society. Ozonation, which is an oxidation reaction with ozone, is an effective and efficient method for the removal of ammonia nitrogen in wastewater because the reaction can proceed at low temperature and atmospheric pressure. Although the researches in ozonation of ammonia nitrogen have been going on for the last five decades, the reaction mechanism has not yet been well understood and the papers focusing on the reaction mechanism are very few. In this short review paper, the progress in oxidation of ammonia nitrogen with ozone both in non-catalytic and catalytic reactions is summarized to provide a better understanding on the reaction mechanism for ozonation of ammonia nitrogen in water.

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Section: Heterogeneous Catalysis Over Mgomentioning

confidence: 83%

Section: Heterogeneous Catalysis Over Mgomentioning

confidence: 96%

Oxidation of Ammonia Nitrogen with Ozone in Water: A Mini Review

et al. 2020

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“…The result obtained in this work is better than that reported in the literature. Thus, Chen et al [8] have shown the N 2 selectivity of 44.8% over MgO-Co 3 O 4 catalyst in the catalytic ozonation of ammonium solution. Liu et al [7] have shown the conversion of 83.2% and gaseous nitrogen selectivity of 51.8% on SrO-Al 2 O 3 catalyst in the catalytic ozonation of ammonium solution.…”

Section: Modification Of Activated Dolomite With Fe 2 Omentioning

confidence: 99%

“…NH 4 + conversion of 83.2% and gaseous nitrogen selectivity of 51.8% were achieved [7]. Chen et al 2018 reported the synthesis of MgO-Co 3 O 4 (molar ratio 8 : 2) and claimed that an ammonia nitrogen removal and gaseous nitrogen selectivity reached to the value of 85.2% and 44.8%, respectively [8].…”

Section: Introductionmentioning

confidence: 99%

Novel Nano-Fe₂O₃-Co₃O₄ Modified Dolomite and Its Use as Highly Efficient Catalyst in the Ozonation of Ammonium Solution

Nguyen

Pham

et al. 2020

Journal of Nanomaterials

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Catalytic ozonation is a new method used for removal of NH4OH solution. Therefore, high catalytic performance (activity and selectivity) should be achieved. In this work, we report the synthesis and catalytic performance of Fe2O3-Co3O4 modified dolomite in the catalytic ozonation of NH4OH solution. Dolomite was successfully activated and modified with Fe2O3 and Co3O4. Firstly, dolomite was activated by heating at 800°C for 3 h and followed by KOH treatment. Activated dolomite was modified with Fe2O3 by the atomic implantation method using FeCl3 as Fe source. Fe2O3 modified dolomite was further modified with Co3O4 by precipitation method. The obtained catalysts were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), N2 adsorption–desorption (BET), and temperature-programmed reduction (H2-TPR). From SEM image, it was revealed that nano-Fe2O3 and Co3O4 particles with the size of 80–120 nm. Catalytic performance of activated dolomite, Fe2O3 modified dolomite, and Fe2O3-Co3O4 modified dolomite in catalytic ozonation of NH4+ solution was investigated and evaluated. Among 3 tested catalysts, Fe2O3-Co3O4 modified dolomite has the highest NH4+ conversion (96%) and N2 selectivity (77.82%). Selectivity toward N2 over the catalyst was explained on the basis of bond strength M-O in oxides through the standard enthalpy ΔH°f of oxide. Catalyst with lower ΔH°f value has higher N2 selectivity and the order is the following: Co3O4 (ΔH°f of 60 kcal (mole O)) > Fe2O3 (ΔH°f of 70 kcal (mole O)) > MgO (ΔH°f of 170 kcal (mole O)). Moreover, high reduction ability of Fe2O3-Co3O4 modified dolomite could improve the N2 selectivity by the reduction of NO3- to N2 gas.

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“…Break-point chlorination causes the formation of chloramines, leading to secondary pollution [8]. Heterogeneous catalytic ozonation, where NH 4 + can be removed as gaseous nitrogen by utilizing a catalyst to decompose ozone and produce hydroxyl radicals, has aroused considerable interest as a promising method [9,10]. Therefore, the key to heterogeneous catalytic ozonation technology is to find a kind of suitable catalyst.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Surfactant-Enhanced Metal Oxides Catalyst for Catalytic Ozonation Ammonia in Water

Chen

Lin

2018

IJERPH

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The new surfactant-enhanced metal oxides composite catalysts have been prepared using solid state method and characterized by the N2-adsorption-desorption, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), and X-ray diffraction (XRD) techniques. Catalytic activity of the synthesized powders has been investigated in the liquid-phase catalytic ozonation ammonia nitrogen (NH4+) (50 mg/L). Especially, the effect of parameters such as optimum molar ratio for metal salt, NaOH and surfactants, temperature, and time of calcinations was also considered. Leveraging both high catalytic activity in NH4+ degradation and more harmless selectivity for gaseous nitrogen, the CTAB/NiO catalyst is the best among 24 tested catalysts, which was generated by calcining NiCl2·6H2O, NaOH, and CTAB under the molar ratio 1:2.1:0.155 at 300 °C for 2 h. With CTAB/NiO, NH4+ removal rate was 95.93% and gaseous nitrogen selectivity was 80.98%, under the conditions of a pH of 9, ozone flow of 12 mg/min, dosage of catalyst 1.0 g/L, reaction time 120 min, and magnetic stirring speed 600 r/min in room temperature.

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Low-temperature conversion of ammonia to nitrogen in water with ozone over composite metal oxide catalyst

Cited by 40 publications

References 23 publications

Oxidation of Ammonia Nitrogen with Ozone in Water: A Mini Review

Oxidation of Ammonia Nitrogen with Ozone in Water: A Mini Review

Novel Nano-Fe₂O₃-Co₃O₄ Modified Dolomite and Its Use as Highly Efficient Catalyst in the Ozonation of Ammonium Solution

Fabrication of Surfactant-Enhanced Metal Oxides Catalyst for Catalytic Ozonation Ammonia in Water

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Low-temperature conversion of ammonia to nitrogen in water with ozone over composite metal oxide catalyst

Cited by 40 publications

References 23 publications

Oxidation of Ammonia Nitrogen with Ozone in Water: A Mini Review

Oxidation of Ammonia Nitrogen with Ozone in Water: A Mini Review

Novel Nano-Fe2O3-Co3O4 Modified Dolomite and Its Use as Highly Efficient Catalyst in the Ozonation of Ammonium Solution

Fabrication of Surfactant-Enhanced Metal Oxides Catalyst for Catalytic Ozonation Ammonia in Water

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Product

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About

Novel Nano-Fe₂O₃-Co₃O₄ Modified Dolomite and Its Use as Highly Efficient Catalyst in the Ozonation of Ammonium Solution