A comparison of soot emitted from school buses and shared auto-rickshaws in Indian tier-II city

Abstract

The soot emitted from diesel vehicles has been identified as a significant source of air pollution. The characteristics of the soot indicate its ability to alter the air quality of the area. This study compared the characteristics of soot particles emitted from two commonly used public transport; diesel-driven school bus (SB) and the shared auto-rickshaw (AR). The differences were found in the soot particles from the SB and AR. The FESEM (field emission scanning electron microscope) reveals that the morphology of the soot particles from both vehicles were spherical. The average size of soot was 207.30 nm (AR) and 251.65 nm (SB). This extreme small-size soot is dangerous to human health. The ratio of oxygen and carbon (O/C) was found as 0.51 and 0.26 in soot samples of AR and SB, respectively. The sharper peaks in FTIR (Fourier transform infrared spectroscopy) show that the functional groups in AR soot were in higher quantity compared to soot of SB. The concentration of total trace metals (TM) (Cu, Cr, Cd, Fe, Ni, Pb, and Zn) was 1.08 times less in soot collected from AR than SB. The study signifies that the characteristics of soot emitting from AR and SB can be utilized as a fingerprint of ambient pollution and it will be helpful in controlling PM emissions.

Keywords:

• Soot
• characterization
• diesel vehicles
• trace metals
• school bus
• share auto-rickshaws

Acknowledgment

We express our gratitude to CRF (central research facility), Department of Applied Geology, and Department of Environmental Science and Engineering, IIT(ISM), Dhanbad for providing research facilities.

Conflicts of interest

The authors declare that they have no conflict of interest.

Funding

This research did not receive any funding.