Application of micro-morphology in the physical characterization of urban road dust--颗粒学报PARTICUOLOGY

Jose, J., & Srimuruganandam, B. (2021). Application of micro-morphology in the physical characterization of urban road dust. Particuology, 54, 146-155. https://doi.org/10.1016/j.partic.2020.05.002

Application of micro-morphology in the physical characterization of urban road dust

Jithin Jose, B. Srimuruganandam ^*

School of Civil Engineering, Vellore Institute of Technology, Vellore 632 014, Tamil Nadu, India

10.1016/j.partic.2020.05.002

Volume 54, February 2021, Pages 146-155

Received 27 December 2019, Revised 7 May 2020, Accepted 9 May 2020, Available online 20 June 2020, Version of Record 28 January 2021.

E-mail: bsrimuruganandam@vit.ac.in

Highlights

• Urban road silt load was studied using scanning electron microscopy.

• Equivalent spherical diameter of most particles was between 10 μm and 30 μm.

• Fine particles had a higher concentration at locations with high-traffic volume.

• Combustion was identified as the major source of spherical particles.

• The major source of mineral particles was crustal material.

Abstract

Urban road dust was collected from Vellore City, Tamil Nadu, India, and analyzed. Scanning electron microscopy (SEM) was used to examine road dust from nine sampling locations in the study region. SEM image analysis was used to identify various shape factors of collected dust particles. The equivalent spherical diameter of most particles was between 10 μm and 30 μm. Fine particles had greater concentrations at locations with higher traffic flow. Particles were categorized into four classes based on their shape factors, viz., spherical, mineral, elongated, or irregular. Spherical particles had the smallest mean equivalent diameter (1.95 μm) and mineral particles had the largest diameter (33.3 μm). Spherical particles made up the smallest portion of road dust (0–12%) in the study region and mineral particles made up the largest (45–65%). Elongated and irregular particles, each made up 23–30% of road dust. Electron dispersive X-ray spectroscopy analysis was used to identify the elemental composition of dust particles. Spherical particles were mostly from combustion sources and mineral particles were largely of crustal origin. No individual source was found for irregular and elongated particles. Biological debris was the major source of irregular particles.

Graphical abstract

Keywords

Road dust; Scanning electron microscopy; Shape factorsSilt load; Size distribution; Particle shapes

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