The main sources of H2S to the atmosphere are geothermal and biogenic. The anthropogenic sources are: · Petroleum refineries · Fish processing industry · Waste treatment plants· Catalysators of motor vehicles The passive sampler for hydrogen sulfide is based on the principle of the diffusion of H2S molecules onto an absorbant medium, in this case Cadmium sulphate. To reduce wind disturbance a glass fibre membrane is attached, supported by a wire net.
Figure left: Determination of sampling rate under various laboratory conditions such as concentration range, humidity and exposure time
Figure right: H2S measurements in the vicinity of fish processing plants over time. Site 1 and 2 are near the fence line of different production plants and site 3 is in aremote residential are in a distance of 8 km. The measurements mirrors the production intensity in a plausible way.
Samplingrate: 10.9 ml/min at 20oC
Working range: 1 - 50 µg/m3
Sampling time: 2 - 4 weeks
Detection limit: 0.1 µg/m3 for a sampling time of 2 weeks
wind speed: influence of wind speed < 10% up to 6.0 m/sec using protection shelters
temperature: no information
humidity: ± 10 % between 20 to 80%
before use: 12 months
after exposure: 3 months
Cross sensitivity: Selective method
Expanded uncertainty*: 15.5 % at concentration level of 5 µg/m3