Emissions from Hot Mix Asphalt Plants and their Impact on Ambient Air Quality

摘要

Hot mix asphalt plants are characterized as air polluting industries. Their pollution potential and impact on the ambient air quality were assessed in the present work. The emission monitoring was conducted in respect of particulate matter and the gaseous pollutants at fifteen representative plants located in different zones of India. The stack emission monitoring results of batch mix plants had shown the concentration of particulate matter varying from 99 to 182 mg/Nm~3 with an average of 128 mg/Nm~3 In case of drum mix plants the average particulate matter concentration was observed as 282 mg/Nm~3. The sulphur dioxide emission results were observed as 114 to 257 mg/Nm~3 and 115 to 217 mg/Nm~3 for the batch mix plants and the drum mix plants, respectively. The nitrogen oxide emissions were noted as 77 to 209 mg/ Nm~3 for the batch mix plants and 79 to 215 mg/Nm~3 for the drum mix plants. The monitoring results had shown that the batch mix plants are less polluting than the drum mix plants in terms of particulate matter emissions. The impacts of emissions from the hot mix plants were assessed by measuring the ambient air quality at upwind and downwind locations in respect of PM_(10), PM_(25), SO_2, NO_2 and CO. Based on the air quality monitoring results, an air quality index was calculated using the linear segmented principle for a given location. It was observed that the emissions from the hot mix plants impact 2 to 94 deterioration in the ambient air quality. The deterioration in air quality is mainly attributed to the fugitive emissions.