da Rosa, MB; Behnke, W; Zetzsch, C: Study of the heterogeneous reaction of O3 with CH3SCH3 using the wetted-wall flowtube technique, Atmospheric Chemistry and Physics, 3, 1665-1673 (2003)
This work presents the heterogeneous kinetics of the reaction of CH3SCH3 (di-Me sulfide, DMS) with O3 (ozone) in aq. solns. of different ionic strengths (0, 0.1 and 1.0M NaCl) using the wetted-wall flowtube (WWFT) technique. Henry's law coeffs. of DMS on pure water and on different concns. of NaCl (0.1M - 4.0M) in the WWFT from UV spectrophotometric measurements of DMS in the gas phase, using a numerical transport model of phase exchange, were detd. to be H (M atm-1) = 2.160.5 at 274.4 K, 1.470.3 at 283.4 K, 0.720.2 at 291 K, 0.570.1 at 303.4 K and 0.330.1 at 313.4 K on water, on 1.0M NaCl to be H = 1.570.4 at 275.7 K, 0.80.2 at 291 K and on 4.0M NaCl to be H = 0.440.1 at 275.7 K and 0.160.04 at 291 K, showing a significant effect of ionic strength, , on the soly. of DMS according to the equation In(H/M atm-1)=4061 T-1 -0.0522-50.9 T-1 - 14.0. At concns. of DMS(liq) above 50M, UV spectrophotometry of both O3(gas) and DMS(gas) enables us to observe simultaneously the reactive uptake of O3 on DMS soln. and the gas-liq. equilibration of DMS along the WWFT. The uptake coeff.,  (gamma), of O3 on aq. solns. of DMS, varying between 1 and 15  10-6, showed a square root-dependence on the aq. DMS concn. (as expected for diffusive penetration into the surface film, where the reaction takes place in aq. soln.). The uptake coeff. was smaller on NaCl soln. in accord with the lower soly. of O3. The heterogeneous reaction of O3(gas) with DMS(liq) was evaluated from the observations of the second order rate const. (kII) for the homogeneous aq. reaction O3(liq) + DMS(liq) using a numerical model of radial diffusion and reactive penetration, leading to kII  kII (in units of 108 M-1 s-1) = 4.1  1.2 at 291.0 K, 2.150.65 at 283.4 K and 1.80.5 at 274.4 K. Aside from the expected influence on soly. and aq.-phase diffusion coeff. of both gases there was no significant effect of ionic strength on kII, that was detd. for 0.1M NaCl, leading to kII  kII (108 M-1 s-1) = 3.2  1.0 at 288 K, 1.70.5 at 282 K and 1.30.4 at 276 K, and for 1.0M NaCl, leading to 3.21.0 at 288 K, 1.30.4 at 282 K and 1.20.4 at 276 K, where the error limits are estd. from the output of the model calcns., taking the variability of individual runs at various DMS levels into account.
Upcoming ...

Fr. 2020-07-10 now
12th BayCEER Workshop 2020: "Call for Abstracts" is open
BayCEER Colloquium:
Th. 2020-11-05
Signaling of rhizosphere microbiome: key for plant health, development and nutrition
Ecological-Botanical Garden:
Su. 2020-10-04
Führung nach Anmeldung: Pflanzen für ein gesundes Herz
Su. 2020-11-01
Führung nach Anmeldung: Palmen und Proteen: Pflanzen für Grabgestecke
Th. 2020-10-29
BayCEER Workshop 2020
BayCEER Blog
Why Science Communication?
Stoichiometric controls of C and N cycling
Flying halfway across the globe to dig in the dirt – a research stay in Bloomington, USA
Picky carnivorous plants?
RSS Blog as RSS Feed
Weather research site
Luftdruck (356m): 962.6 hPa
Lufttemperatur: 19.8 °C
Niederschlag: 0.3 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 17m): 8.4 km/h
Wind (Max.): 14.4 km/h
Windrichtung: SW

Globalstrahlung: 273 W/m²
Wind (Höhe 32m): 0.0 km/h

This site makes use of cookies More information