[Seasonal Variation and Source Apportionment of Water-Soluble Ions in PM in Quanzhou City].

In this study, the seasonal characteristics of water-soluble ions (WSIs) present in fine particulate matter (PM) in Quanzhou City were investigated. PM samples were collected at five different sites in the city from March 2014 to January 2015 and the concentrations of Na, NH, K, Ca, Mg, F, Cl, NO, and SO were determined by ion-exchange chromatography. In order to identify the sources of these WSIs, the positive matrix factorization (PMF) analysis was applied. The seasonal variations in total WSI concentrations were found to decrease in the order of spring > winter > summer > autumn. The ions SO, NO, and NH were the major WSIs found in PM, accounting for 90.3%±3.3%, 68.8%±11.7%, 78.9%±7.1%, and 74.0%±18.4% of the total amount of ions found in spring, summer, autumn, and winter, respectively. These results suggested that the level of secondary ions was relatively high in the spring season. The anion-to-cation ratio in each of the four seasons was less than one, which indicated that PM in Quanzhou City was slightly alkaline. Furthermore, NH ions in PM mostly existed in the form of (NH)SO, NHHSO, and NHNO during spring and winter, while they were primarily found as NHHSO and NHNO in the summer and autumn seasons. PMF analysis revealed that marine salt, secondary sources, fugitive dust from construction, municipal incineration, and biomass burning were the main potential sources of the ionic components of PM.