Chemical characteristics and Pb isotopic compositions of PM2.5 in Nanchang, China--颗粒学报PARTICUOLOGY

Zhao, Y., Yu, R., Hu, G., Lin, X., & Liu, X. (2017). Chemical characteristics and Pb isotopic compositions of PM2.5 in Nanchang, China. Particuology, 32, 95-102. https://doi.org/10.1016/j.partic.2016.07.009

Chemical characteristics and Pb isotopic compositions of PM_2.5 in Nanchang, China

Yang Zhao ^{a b}, Ruilian Yu^a *, Gongren Hu ^a *, Xiaohui Lin ^a, Xianrong Liu ^a

a College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
b Environmental Protection Agency of Nanchang City, Nanchang 330038, China

10.1016/j.partic.2016.07.009

Volume 32, June 2017, Pages 95-102

Received 13 April 2016, Revised 17 July 2016, Accepted 22 July 2016, Available online 11 January 2017, Version of Record 20 April 2017.

E-mail: ruiliany@hqu.edu.cn; grhu@hqu.edu.cn

Highlights

• In autumn 2013, PM_2.5 samples were collected at six sites in Nanchang, China.

• Results of water-soluble ions indicated obvious anthropogenic sources in PM_2.5.

• Coal combustion and vehicle exhaust were both contributors to PM_2.5 based on the NO₃⁻/SO₄²⁻.

• The main sources of 29 trace elements were coal-burning, vehicle exhaust and metal smelting.

• Coal combustion and construction activities were the main Pb sources based on Pb isotope tracing.

Abstract

In mid-September 2013, PM_2.5samples were collected at six sites in Nanchang, Jiangxi Province, China, to quantify nine water-soluble ions (Ca²⁺, Mg²⁺, K⁺, Na⁺, NH₄⁺, SO₄²⁻, Cl⁻, F⁻, NO₃⁻), 29 trace elements (Ba, Zn, Pb, Ni, Mo, Cr, Cu, Sr, Sb, Rb, Cd, Bi, Zr, V, Ga, Li, Y, Nb, W, Cs, Tl, Sc, Co, U, Hf, In, Re, Be, and Ta), and to characterize Pb isotopic ratios (²⁰⁷Pb/²⁰⁶Pb, ²⁰⁸Pb/²⁰⁶Pb, and ²⁰⁷Pb/²⁰⁴Pb) for identifying the main source(s) of Pb. The results showed that the average daily PM_2.5 concentration (53.16 ± 24.17) μg/m³ was within the secondary level of the Chinese ambient air quality standard. The combined concentrations of SO₄²⁻, NH₄⁺, and NO₃⁻ to total measured water-soluble ion concentrations in PM_2.5 ranged from 79.40% to 95.18%, indicating that anthropogenic sources were significant. Coal combustion and vehicle emissions were both contributors to PM_2.5 based on the NO₃⁻/SO₄²⁻ ratios. Wushu School experienced the lowest concentrations of PM_2.5 and most trace elements among the six sampling sites. Enrichment factor results showed that Tl, Cr, In, Cu, Zn, Pb, Bi, Ni, Sb, and Cd in PM_2.5 were affected by anthropogenic activities. Cluster analysis suggested that Cd, Sb, Pb, Re, Zn, Bi, Cs, Tl, Ga, and In were possibly related to coal combustion and vehicle exhaust, while Ni, Nb, Cr, and Mo may have originated from metal smelting. Pb isotopic tracing showed that coal dust, cement dust, road dust and construction dust were the major Pb sources in PM_2.5 in Nanchang. Combined, these sources contributed an average of 72.51% of the Pb measured, while vehicle exhaust accounted for 27.49% of Pb based on results from a binary Pb isotope mixed model.

Graphical abstract

Keywords

PM_2.5; Water-soluble ions; Trace elements; Pb isotopic composition; Nanchang

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