Characterization of water-soluble ions in PM10 over an industrial area in northern Colombia: Temporal variations and correlation with satellite data

Abstract

This study was designed to assess the concentrations of nine water-soluble ions in PM10 mass at two sites of an open-pit coal mine and to analyze the correlation and variation of the spatial distribution of sulfate ions with the PM10 sulfate aerosol optical depth at 550 nm (suaod550) in two (North and South) stations of the study area. The daily average of PM10 concentrations ranged from 20.48 to 53.10 μg/m3 and thus did not exceed the daily average maximum permissible level of PM10 (100 μg/m3) established in the Colombia standard at any station. The concentrations of nine water-soluble ions in PM10 (Cl−, NO3−, PO43−, SO42– Na+, NH4+, K+, Mg2+, and Ca2+) were determined. The ions under analysis, SO42−, Na+, and NH4+ had the highest concentrations. Combined, they accounted for 75% of the mass of water-soluble ions in a total of 210 samples. The SO42− concentrations in PM10 significantly correlated with suaod550 (r ranging from 0.57 to 0.66), emphasizing the strong effect of suaod550 from Venezuela (Lake Maracaibo) on central and northern Colombia. These results demonstrate that the effects of local sulfate emissions near monitoring sites can be predicted and assessed using satellite data.

Keywords

• PM10
• Water-soluble ions
• Sulfate-aerosol
• Correlation
• Marine-aerosols