Morphologic and chemical composition of particulate matter in motorcycle engine exhaust.

V.V Chernyshev,Ya O Mezhuev,L.H Hai,A.M Tsatsakis,A.M Zakharenko,A.S Kholodov,T.T Hien,A.K Stratidakis,K.S Golokhvast,T.I Burykina,S.M Ugay

doi:10.1016/j.toxrep.2018.01.003

Abstract

Despite the fact that environmental pollution due to motorcycle exhaust gases reports a great increase, motorcycle production exhibits a great increase through the last years. Countries of Asia and Africa are reported to be the major regions where two-wheeled vehicles are a major transportation mode, with tens of millions of units sold per year. Motorcycle exhaust particles are considered to be the major contributor to environmental pollution due to their airborne dispersion, containing great amount of polycyclic aromatic hydrocarbons (PAHs). This study aims at reporting an objective analysis of the main sources of the ambient air pollution as also particle size distribution and chemical composition analysis of particulate matter originated from the exhausts of two-wheeled vehicles used in the territory of Vladivostok, Russia. Various types of two-wheeled vehicles were examined (motorcycles, ATVs, scooters and wet bikes) using different types of engine and fuel system. Experimental results showed that there was no clear relation to the particle size distribution with the engine displacement of motorcycle and the number of strokes and the fuel system. Instead, there were reported two clear assumptions. The first one is that regarding to the motorcycle brand, a few samples did not exhibit a great percentage of PM10 fraction. The second one is that more modern vehicles, that have a harmful gas afterburning system, are usually the source of an increased percentage of PM10 emitted particles. At last, it should be mentioned that the laser particle size analysis method is capable of determining the particle sizes after their agglomeration whereas the optical morphometry method allows to determine the real particle size of emissions. In conclusion, it can be pointed out that the agglomeration of particles can lead to the reduction in the toxicity of particles emissions originated from two wheeled-vehicles.

Highlights

Polycyclic aromatic hydrocarbons (PAHs) are a group of hazardous chemicals, toxic to human health [1,2,3] while considered as potent atmospheric pollutants when found in the environment, as many of their compounds have been identified as carcinogenic, mutagenic, and teratogenic to microorganisms [4,5,6,7]
According to the results obtained by laser particle size analysis for sample 1, it was found that particle size distribution exhibits an increase in the percentages of particles sized over the particles with a diameter between 2 (PM10) fraction (Fig. 1)
According to the results from optical morphometry it is shown that the percentage of particles sized under the PM10 fraction is 68,69%

Summary

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are a group of hazardous chemicals, toxic to human health [1,2,3] while considered as potent atmospheric pollutants when found in the environment, as many of their compounds have been identified as carcinogenic, mutagenic, and teratogenic to microorganisms [4,5,6,7]. PAHs are mainly anthropogenic, originated from incomplete combustion of fuels in the engines of transportation means. Various types of vehicles have been examined concerning their pollutant emissions [9,10,11,12] where motorcycles and diesel powered cars have proved to be the main sources of maximum emissions of particulate matter, while in many countries it is reported that the major polluting factor of ambient air comes from the emissions of motorcycles, comparing to all transportation modes [13]. Despite the small engine displacement of two-wheeled vehicles, comparing to automobiles, the particulate matter originated from motorcycles’ exhaust gases is reported to be greater in amount than PM originated from automobiles while exhibited stronger PAH-related.

Objectives

Results

Discussion

Conclusion