Hydrogen sulfide emission from the Ardiyah sewage treatment plant in Kuwait Original Research Article

Many complaints were received from citizens living around the Ardiyah sewage treatment plant (ASTP) about the presence of an odor that might be harmful to their health or property. Others working near the plant complained of various diseases that took longer than normal to be cured. Therefore, emission of hydrogen sulfide (H2S) was selected to be studied. A survey of the standard limits and health effects and a visual inspection of the ASTP to specify any source of emission were made. The formation process of H2S was investigated, specifying the source of emission; the locations of these sources as a function of x and y directions with respect to a reference point or origin of computation were specified, the location of about 15 discrete receptors measuring real concentration of H2S around the ASTP were also specified referring to the reference point. The rate of emission of hydrogen sulfide in the atmosphere, as a result of the total sulfide dissolved in the inlet wastewater flow, was calculated. Meteorological data (wind speed, direction, etc.) were collected. The concentration of H2S as measured by sensors around the plant was reported. Then a model was applied to the ASTP, and the contour lines according to the dispersion model were illustrated. The data from the dispersion model and the real values from sensors around the ASTP were compared, and the locations of the maximum and minimum concentrations with the measured values were specified. Results from the dispersion model showed that the main problem exists inside the ASTP, where 6 ppm of H2S concentration was reported by the simulator model, whereas outside the ASTP, there was no serious problem. The maximum concentration reported outside the ASTP at a distance in the x-direction — x being greater than 700 m — was 0.053 ppm, which decreased as x increased. None of the concentrations predicted by the model exceeded the standard value as specified by the Occupational Safety and Health Administration (10 ppm), whereas some real sensor measurements at the ASTP exceeded the standard, reaching a value of 37 ppm. Recommendations are suggested according to the model and the real values of HZS concentrations in emissions to solve the odor problem at the ASTP in Kuwait.