Atmospheric Particulates and Ionic Pollutants Study at Wu-Chi, Central Taiwan

Abstract

This study characterizes ambient air particulate mass and ionic species near industrial zones and the Taiwan Strait in central Taiwan. Analysis results indicated that average particulate mass concentration at the sampling site for fine particulate matter (PM_2.5) and coarse (PM_{2.5 − 10}) particles were 40.1 ± 21.1 (μ g/m³) and 26.7 ± 14.3 (μ g/m³), respectively. Analysis of the average component percentage of various kinds of ionic species showed that the major components of PM_2.5 were SO₄ ^{2 −}, NO_3, ⁻ and NH₄ ⁺. Their possible origin is from the combustion of fossil fuels for power and transportation, as well as from manufacturing processes. Furthermore, the major components of PM_{2.5 − 10} were NO₃ ⁻, Na⁺, Ca^{2 +}, SO₄ ²⁻ and Cl⁻. Their possible origin is from vehicle emissions, crustal materials, secondary aerosols, biomass burning, industrial emissions, and marine spray. Nevertheless, the emission source for the SO₄ ^{2 −}, NO₃ ⁻, and NH₄ ⁺ was situated close to a roadway (approximately 10 m away). And the emission source for the Cl⁻, Na⁺ and Ca^{2 +} was situated close to seaboard (approximately 2 km away). Moreover, the emission source for SO₄ ^{2 −} had originated from the Taichung power plant, which was approximately 2 km away from the sampling site. As presented in a previous study, the Taichung power plant was responsible for the high concentration of SO₄ ²⁻ in this region (Fang et al., 1999; Fang et al., 2006).

Keywords:

• PM_2.5
• PM_{2.5 − 10}
• ionic species
• ion chromatography
• meteorology

Acknowledgements

The authors gratefully acknowledge the National Science Council of the ROC (Taiwan) for financial support under project No. NSC 95-2221-E-241-012-MY3 (NSC95).