Air pollution modeling for petrochemical industries in coastal areas

Air dispersion modeling is the mathematical estimation of pollutants from the emissions sources within a study area. This research focuses on how to rank air toxics from petrochemical industries in Yanbu industrial city in Saudi Arabia and assess their concentration levels at various receptor locations with time. To accomplish this objective, various processing involved in petrochemical industries were reviewed and for selected industries, emission inventory was developed using two sets of emission factor database (USEPA & WHO) and process involved, considering major pollutants simulation runs were made using AERMOD model. To estimate concentration levels at various receptors ambient air quality and meteorological data for three years were collected from petrochemical complex in Yanbu. Upper air and surface meteorological data were processed for use in the dispersion model AERMOD. A critical evaluation on mixing height estimation in urban area from radiosonde is presented; MH method from Sodar is also discussed briefly. A comparative evaluation is presented for the three years data of model in the region considering meteorological data gaps and uncertainties in the emission inventory compilation. Results shows pollution decreases uniformly from 2006 to 2008 and values are reasonable as per standards of Saudi Arabia. Most of the cases pollutants go towards the sea and from Yanbu to Jeddah directions. MH from radiosonde balloon gives non uniform values due to missing data; Comparing of AERMET processing MH and eight diagnostic models show Ayra [1981] correlates better. This study will help in determining long-term impact of pollutants on human health in the vicinity of the industrial complex and also in identifying mitigation measures and pollution control technologies for current operation and future expansion plan.