Behavior of Ambient Ozone on Different Land Use

Abstract

               The research study of ambient ozone behaviour on difference land use activities in different time period. This study scopes on 24 hours periods, 3 days consecutive in three different areas: 1) Maptaphut, Rayoung, one of Thailand major industrial districts; 2) Phahonyothin, Bangkok, which represent as an urban area; and 3) a rural area in Laem Phak Bia research station, Petchaburi. The result of this project shows a distinctive result where Ozone (O₃) concentration were found in highest volume at an average of 22.20±9.66 ppb in Laem Phak Bia, followed by 16.71±5.21 ppb in Maptaphut industrial zone, and 5.54±3.25  ppb in downtown Phahonyothin. Results of ozone concentration were also studied and explained in diurnal variations concentration values, where the highest ozone concentration volume in both industrial and urban zones were found at 02:00 PM, whereas the rural zone was found at 04:00 PM. Opposition to the lowest ozone volumes data, where the lowest concentration in industrial zone was found at 07:00 AM, whereas both of urban and rural zones were found at 06:00 AM. This result could be explained as the ozone concentration volume is related directly to the photochemical reaction from solar radiation. Other interest is the concentration data of ambient Nitrogen elements (NO_x) in the study areas, where rural area shows a lowest volume at an average of Nitrogen elements 2.15±0.98 ppb, followed by industrial district 11.08±3.99 ppb, while the urban area shows a highest volume at an average of 90.03±43.45 ppb. The difference of Nitrogen elements is directly related to difference of land use, and human activities in these three different areas. In summary, Ozone concentration can be varied due to land use activities, time periods in which solar radiation and its photochemical reaction played a main role, and photochemical reaction on oxides of Nitrogen elements in area.

Keywords: ozone, air pollution, micrometeorology