| dc.description.abstract | The emission of Hydrogen sulphide (H2S) gas during the development of geothermal resource is
a significant environmental aspect of concern that must be considered in any environmental
management plan. Hydrogen sulphide gas is an extremely toxic and irritating gas. This research
work sought to investigate the transport and dispersion of Hydrogen sulphide gas over the
Greater Olkaria Geothermal area on a diurnal scale.
The transport and dispersion of Hydrogen sulphide gas over the Greater Olkaria Geothermal area
was investigated using temporal analysis, correlation analysis, spatial analysis. Temporal
analysis shows that the highest concentrations of Hydrogen sulphide were obtained when winds
are calm and atmospheric temperatures are low. In Olkaria geothermal area, these weather
conditions exist between 2000hrs and 0600hrs local time. The study suggests that if these
weather conditions persist over prolonged period, Hydrogen sulphide gas concentrations around
the power plants may rise to unsafe levels with respect to human health. There is need for a
continuous monitoring of H2S gas particularly when weather conditions point towards building
up of H2S gas concentration around the power plant.
Spatial and temporal analysis affirms that fairly high concentration of H2S gas occurred close to
the source points. In all the three averaging times (1-hourly, 8-hourly and 24-hourly) considered
during the modeling of transport and dispersion of Hydrogen sulphide gas, high gas
concentration were noted close to emission points and disperses away with distance. It can be
concluded that the transport and dispersion of H2S gas at Olkaria geothermal field is dependent
on the prevailing weather conditions.
Early recognition and detection of the concentration of H2S gas in the atmosphere is crucial in
protecting employees and people living around geothermal power plants or any active
geothermal area from deadly exposures. Employees working in areas that contain or have the
potential to contain H2S gas, should learn to recognize the signs and symptoms of H2S gas
exposure, monitor and take measures to protect themselves. Information on the concentration of
H2S gas, transport and dispersion is so critical hence it should be disseminated to the public to
ensure their health and safety. | en_US |
