Author: Chem / Mohammed Gamal-el-Din Tayel
It is known that the exposure to Sulfur dioxide and hydrogen sulfide irritates the respiratory system, which can cause bronchial restrictions leading to symptoms such as coughing, wheezing or shortness of breath. This is why these specific pollutants needed to be monitored in urban and industrial areas. The available data for sulfur dioxide (SO2) and hydrogen sulfide (H2S) concentrations which exist in ambient air of the city of Alexandria has been displayed in this study in order to assess the actual levels of sulfur dioxide and hydrogen sulfide and make recommendations for future monitoring. Globally, the main emission sources for sulfur dioxide are volcanoes and fossil fuels. In Alexandria, the main emission sources are motor vehicles, energy production, shipping as well as other fuel combustion and petroleum refining. The main emission areas of hydrogen sulfide are Lake Mareotis, petroleum refineries with recovery plants and sanitary (waste water). Monitoring locations and instrument The monitoring locations are: the industrial Area (Wady Elkamar – El Max) – Urban area (Horrya Avenue) – Residential area (Sidi Beshr Bahary ) – Background area (Faculty of Science, Anfoushi – Alexandria ). The concentration levels of sulfur dioxide (SO2) were determined by Pulsed fluorescence SO2/H2S/CS analyzer Results: Diurnal variations: The present study shows that maximum concentrations of sulfur dioxide are in the urban and industrial areas which may be due to the presence of pollutants emission sources. The increase in sulfur dioxide concentrations in urban areas was detected during the rush hours, while relatively high sulfur dioxide concentrations in the industrial area were detected throughout the day. Seasonal variations: The highest values of sulfur dioxide concentration were obtained during winter. This may be due to the low wind speed which leads to the accumulation of pollutants in the monitored locations. Next are the levels of sulfur dioxide concentration during summer which may be due to the circumstances following the 25th January revolution and the absence of the security role which leads to the increase in illegal activities of construction and demolition of houses within Alexandria which consequently leads to the increase of heavy trucks to transfer the building materials and demolition waste. Another factor which enhances sulfur dioxide emission is the increase in population during summer holidays. Meteorological parameter effects: The study of the effect of meteorological parameters such as: wind velocity, temperature and relative humidity on sulfur dioxide concentrations shows an inverse relationship between sulfur dioxide concentrations and wind speed during winter in all monitoring sites. The main recommendations: (1) More trees need to be planted, especially in industrial and urban area. (2) Low sulfur fuel should be used. (3) Different vehicles need to apply exhaust treatment (three way catalytic converters).