scholarly journals Gas-phase chemiluminescence of reactive negative ions evolved through corona discharge in air and O2 atmospheres

RSC Advances ◽  
2017 ◽  
Vol 7 (26) ◽  
pp. 15926-15930 ◽  
Author(s):  
Dingkun Zhang ◽  
Yongzan Zheng ◽  
Xiangnan Dou ◽  
Syed Niaz Ali Shah ◽  
Jin-Ming Lin

The reactive performance of negative ions evolved in air and O2 atmospheres through a gas-phase chemiluminescence method was investigated.

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 549
Author(s):  
Maarja Kask ◽  
Marina Krichevskaya ◽  
Sergei Preis ◽  
Juri Bolobajev

The treatment of wastewaters containing hazardous volatile organic compounds (VOCs) requires the simultaneous treatment of both water and air. Refractory toluene, extensively studied for its removal, provides a basis for the comparison of its abatement methods. The oxidation of aqueous toluene by gas-phase pulsed corona discharge (PCD) in combination with the subsequent photocatalytic treatment of exhaust air was studied. The PCD treatment showed unequalled energy efficiencies in aqueous and gaseous toluene oxidation, reaching, respectively, up to 10.5 and 29.6 g·kW−1·h−1. The PCD exhaust air contained toluene residues and ozone in concentrations not exceeding 0.1 and 0.6 mg·L−1, respectively. As a result of the subsequent photocatalytic treatment, both airborne residues were eliminated within a contact time with TiO2 as short as 12 s. The results contribute to the possible application of the studied approach in closed-loop energy-saving ventilation systems.


1995 ◽  
Vol 73 (12) ◽  
pp. 2263-2271 ◽  
Author(s):  
Christine C.Y. Chow ◽  
John M. Goodings

A pair of laminar, premixed, CH4–O2 flames above 2000 K at atmospheric pressure, one fuel-rich (FR) and the other fuel-lean (FL), were doped with ~10−6 mol fraction of the second-row transition metals Y, Zr, Nb, and Mo. Since these hydrocarbon flames contain natural ionization, metallic ions were produced in the flames by the chemical ionization (CI) of metallic neutral species, primarily by H3O+ and OH− as CI sources. Both positive and negative ions of the metals were observed as profiles of ion concentration versus distance along the flame axis by sampling the flames through a nozzle into a mass spectrometer. For yttrium, the observed ions include the YO+•nH2O (n = 0–3) series, and Y(OH)4−. With zirconium, they include the ZrO(OH)+•nH2O (n = 0–2) series, and ZrO(OH)3−. Those observed with niobium were the cations Nb(OH)3+ and Nb(OH)4+, and the single anion NbO2(OH)2−. For molybdenum, they include the cations MoO(OH)2+ and MoO(OH)3+, and the anions MoO3− and MoO3(OH)−. Not every ion was observed in each flame; the FL flame tended to favour the ions in higher oxidation states. Also, flame ions in higher oxidation states were emphasized for these second-row transition metals compared with their first-row counterparts. Some ions written as members of hydrate series may have structures different from those of simple hydrates; e.g., YO+•H2O = Y(OH)2+ and ZrO(OH)+•H2O = Zr(OH)3+, etc. The ion chemistry for the production of these ions by CI in flames is discussed in detail. Keywords: transition metals, ions, flame, gas phase, negative ions.


Author(s):  
Iakov Kornev ◽  
Sergei Preis

AbstractWastewaters polluted with non-biodegradable volatile organic compounds (VOCs), such as aromatic substances, present a growing problem meeting no adequately affordable technological response. Low-temperature plasma generated in the gas-phase pulsed corona discharge (PCD) presents competitive advanced oxidation technology in abatement of various classes of pollutants, although the process parameters, the pulse repetition frequency and the liquid spray rate, require optimization. The experimental research into aqueous benzene oxidation with PCD was undertaken to establish the impact of the parameters to the energy efficiency. The oxidation reaction was found under the experimental conditions to mostly proceed in the gas phase showing little influence of the pulse repetition frequency and the gas-liquid contact surface. Oxidation of benzene and, presumably, other volatile pollutants in the volume of PCD reactor compartment presents an effective strategy of aqueous VOCs abatement.


1991 ◽  
Vol 56 (2) ◽  
pp. 607-612 ◽  
Author(s):  
Steen Ingemann ◽  
Roel H. Fokkens ◽  
Nico M. M. Nibbering

1983 ◽  
Vol 49 (2) ◽  
pp. 113-122 ◽  
Author(s):  
R.N. Compton ◽  
P.W. Reinhardt ◽  
H.C. Schweinler

1990 ◽  
Vol 43 (9) ◽  
pp. 1479 ◽  
Author(s):  
PCH Eichinger ◽  
JH Bowie

Allyl vinyl ether is reported to undergo a facile Wittig rearrangement to yield penta-1,4-dien-3-ol under base- catalysed conditions in the condensed phase. In marked contrast, the Wittig rearrangement is not a major reaction in the gas phase. Instead, initial rearrangement occurs by a Claisen process and subsequent fragmentations involve some of the most complex interconversions yet proposed for negative ions.


2013 ◽  
Vol 418 ◽  
pp. 012128 ◽  
Author(s):  
Hua Ren ◽  
Na Lu ◽  
Kefeng Shang ◽  
Jie Li ◽  
Yan Wu

2017 ◽  
Vol 23 (49) ◽  
pp. 11752-11756 ◽  
Author(s):  
Anna Troiani ◽  
Marzio Rosi ◽  
Stefania Garzoli ◽  
Chiara Salvitti ◽  
Giulia de Petris

Sign in / Sign up

Export Citation Format

Share Document