Identifying source apportionment of atmospheric particulate matter and gaseous pollutants using receptor models : A case study of Bengaluru, India

Abstract

The data of Particulate matter PMs (PM_2.5, PM₁₀) and Gaseous Pollutants such as carbon monoxide (CO), methane (CH₄), oxides of nitrogen (NOx: NO and NO₂), non-methane hydrocarbons (NMHCs), sulfur dioxide (SO₂), along with ammonia (NH₃) at five different locations across Bengaluru from 1^st January, 2017 to 20^th March, 2018 were collected. The primary objective of this research work is to identify the sources of atmospheric particulate matter and gaseous pollutants using receptor models in Bengaluru, India. To execute this, receptor models, namely Conditional Bivariate Probability Function (CBPF) and Concentrated Weighted Trajectory (CWT) Analysis, are applied. Conditional Bivariate Probability Function (CBPF) shows that, annually, the maximum concentrations of PMs over receptor sites were detected during low wind speed (< 2 knots) along the north-east direction specifying that the long-range transport does not play an essential role in the transportation of higher concentrations of PM and their primary source region may be localized. Concentrated Weighted Trajectory (CWT) analysis shows that, seasonally, the highest air mass contribution of about 37% was noticed in summer, whereas the lowest was in the post-monsoon season (13%). The significant contribution of PM_2.5 transported from long distances was during monsoon, and in the case of PM₁₀, it was in summer. The study suggests that the long-range transport of PMs and gaseous Pollutants was not vital and was observed to be localized.