Real World Emissions of Aerosol And Its Climate Relevant Properties from Light and Heavy-Duty Commercial Vehicles Operated On Road

Abstract

Emissions from road transport plays key role in local air pollution, climate change and human health risk. Diesel exhaust emissions are the primary source of carbonaceous aerosol including particulate matter (PM) and light absorbing carbon. Emissions of fine aerosol and gaseous pollutants from automobiles depend on technology, fuel type, road type and driving behavior which are expected to be different in India. Presents study reports the real-world tailpipe emission factors of pollutants from light-duty (goods) and heavy-duty vehicles during on-road operation for the first time in India. A sampler for mobile sources has been designed and evaluated and was used to collect the PM mass on filters and to measure aerosol absorption and scattering coefficients. The sampler comprises of an inlet system, portable dilution tunnel (PDT) with ejector, zero air generator, PM sampler with cyclone and filter holders, aethalometer, nephelometer and DC power unit. The particle losses inside PDT were found insignificant at 40 and 60 dilution ratios. The on-road emission measurements of trucks, tractors and light motor vehicle-goods (LMV-Goods) were conducted in Rajgir in Bihar, India. The PM2.5 mass collected on filters were utilized for gravimetric analysis, EC-OC analysis, and others chemical constituents. PM emission factors obtained in present study were 1.1 ± 3.1 and 1.7 ± 4.1 g/kg for LMV-goods and HDV-trucks which were found to be considerably different from those measured in the laboratory using standard driving cycle. These new on-road emission factors would be helpful in emission inventories improvement which has implications on climate change assessment. In present work particle loss and formation, emission factors (g/kg) and city-wise emissions of climate relevant aerosol constituents will be discussed.