Carrying Capacity Based Air Quality Management at an Industrial area

India is witnessing a rapid industrial and urban development. Over the last two decades the number of critically polluted industrial areas was radically expanded and pollutant concentrations were reported several folds higher than the recommended standards. In this regard, an effective air quality management is highly useful to abate air pollution. In the present study, a different approach of quantification of carrying capacity (i.e. upper limit of emissions a region can take without infringing permitted pollutant standards) was utilized for air quality management at Manali industrial area (Chennai, Tamil Nadu). Manali is a severely polluted industrial cluster dominated by refineries and petrochemical industries. Carrying capacity was quantified by 3 approaches namely i) qualitative approach utilizing micro meteorological parameters, ii) atmospheric flow conditions utilizing stagnation, ventilation and recirculation events and iii) quantitative approach using AERMOD dispersion model utilizing emissions and meteorological parameters. In order to know the most preferable conditions of industrial operations, temporal carrying capacity analysis was performed that corresponded to critical, high, medium and low pollution levels. Bottom up approach was utilized to prepare the inventory of sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and particulate matter (PM₁₀) emissions at a fine resolution in Manali. Results showed the amount of SO₂, NO₂and PM₁₀emitted to the environment was 22, 7.8 and 7.1 tonnes/day respectively. The carrying capacity of the region with respect to SO₂was estimated to be 16.05 tonnes/day, NO₂was 17.36 tonnes/day, and PM₁₀was 19.78 tonnes/day. Temporal analysis of carrying capacity showed post-monsoon had the lowest emission carrying limit, trailed by winter, summer, and monsoon seasons. The carrying capacity of SO₂during post-monsoon and winter seasons was estimated to be 35% and 26% lower, when compared to the monsoon season. Further, qualitative approach of carrying capacity indicated low carrying capacity at Manali during winter and post monsoon seasons.