Assessment of Source Profile of Nonmethane Hydrocarbon in the Ambient Air of Metro City Delhi, India

Abstract

In this paper presents the assessment of source profile of nonmethane hydrocarbons (NMHCs) in the ambient air of Delhi. The samples were collected from five different urban sites using tedlar bags for aliphatic NMHCs and activated adsorption charcoal tubes for aromatic NMHCs during October 2014 to September 2015. Eleven aliphatic NMHCs propane, n-butane i-butene, i-butane, 1,3-butadiene, trans-2-butene, cis-2-pentene, n-pentane, n-hexane, heptane and four aromatic NMHCs benzene, toluene, o-xylene, p/m-xylene were identified in 112 urban ambient air samples. Samples were analysed using gas chromatography which is coupled with flame ionization detector (GC-FID). Pearson correlation coefficient (r) found to be = 0.5±0.2, shows significance level to have moderate among the NMHCs, indicates NMHCs in the urban ambient air have many sources profile mentioned in PCA result. Factor analysis(FA) and receptor model, i.e., Principal Component Analysis(PCA)/Absolute Principal Component Score (APCS) was used for identification of source profile distribution. PCA analysis after the varimax rotation have identified six possible source profile and explained about 70 % of the total dataset. The average % contribution of NMHCs emitted from vehicles was found to be 23%, whereas polymer manufacturing industries contributes 19% and from refinery operation/ gas station contribute 14%, and 13%, emitted from flare emissions and 10% from natural gas emissions. The secondary industrial process, including paints, body soaps and metal fabricator and processing was contributing 8%. Out of these remaining 13% was estimated as unidentified sources. These findings may be used by government authorities to formulate policies and strategies for improvement of urban air quality that can improve the health of urban communities.

Elemental Characteristics of Respirable Particulate Matter in the Urban Atmosphere of Dehradun, Uttrakhand, India

“…The components having eigen value greater than 1.0 were chosen for the identification of the possible sources. 4,25 Table 2 shows the rotated component matrix for the collected PM 10 across the city of Dehradun for all the seasons. Three principle components were identified, explaining a cumulative variance of 81.75%.…”

A Review on the Atmospheric Non Methane Hydrocarbons (Nmhcs) Study in India

“…On the global scale about 17-27 TgC/yr of NMHCs emission is released into the atmosphere due to industrial usage of solvents and household products such as paints, adhesives, coating and varnishes 10,11 shown in Table 2. NMHCs such as ethane, ethylene, acetylene, propane, propylene, n-butane, 1,3-butadiene, i-butane, cis-2-butene, trans-2-butene, pentane, i-pentane, cis-2-pentene, n-hexane, n-heptanes, benzene, toluene, m/p-xylene, o-xylene are major compounds in the atmosphere emitted from the mobile sources 10,11,15 . NMHCs emissions from landfilling are relatively low and in the environment their contributions have accounted less than 1 %.…”

“…They also calculated the annual mixing ratios of ethane (1.8±1.0), ethene(0.7±0.9),propane (0.6±0.8),propene(0.6±0.7),i-butane (0.6±0.7),nbutane(0.5±0.6), acetylene(1.0±0.8), and i-pentane (0.5±0.6) ppbv at the Nainital, India. Kumar et al, 15 studied on the source profile of NMHCs using Principal Component Analysis (PCA) in the Metro city of Delhi. They found most of the NMHC in the urban environment of Delhi, was emitted from vehicular exhaust (23%), polymer manufacturing industries (19%), refinery operation/ gas station(14%), flare emissions(13%), natural gas emissions (10%), secondary industrial process, including paints, body soaps and metal fabricator and processing (8%) and remaining 13% from an unidentified source.…”