Chemical characteristics of water-soluble ions in particulate matter in three metropolitan areas in the North China Plain

Xu Dao; Zhen Wang; Yibing Lv; Enjiang Teng; Linlin Zhang; Chao Wang

doi:10.1371/journal.pone.0113831

Chemical characteristics of water-soluble ions in particulate matter in three metropolitan areas in the North China Plain

PLoS One. 2014 Dec 1;9(12):e113831. doi: 10.1371/journal.pone.0113831. eCollection 2014.

Authors

Xu Dao¹, Zhen Wang², Yibing Lv¹, Enjiang Teng¹, Linlin Zhang¹, Chao Wang¹

Affiliations

¹ China National Environmental Monitoring Centre, Beijing, China.
² School of Resource and Environmental Sciences, Wuhan University, Wuhan, Hubei, China; Department of Geography, University of California Santa Barbara, Santa Barbara, California, United States of America.

Abstract

PM2.5 and PM10 samples were collected simultaneously in each season in Beijing, Tianjin and Shijiazhuang to identify the characteristics of water-soluble ion compositions in the North China Plain. The water-soluble ions displayed significant seasonal variation. The dominant ions were NO3(-), SO4(2-), NH4(+) and Cl(-), accounting for more than 90% and 86% to the mass of total water-soluble ions in PM2.5 and PM10, respectively. The anion/cation ratio indicated that the ion acidity of each city varied both between sites and seasonally. Over 50% of the ion species were enriched in small particles ≤1 µm in diameter. The [NO3(-)]/[SO4(2-)] ratio indicated that vehicles accounted for the majority of the particulate pollution in Beijing. Shijiazhuang, a city highly reliant on coal combustion, had a higher SO4(2-) concentration.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants / analysis*
China
Cities*
Environmental Monitoring*
Ions / analysis*
Particle Size
Particulate Matter / analysis*
Seasons
Water / chemistry*

Substances

Air Pollutants
Ions
Particulate Matter
Water

Grants and funding

This work was supported by National Natural Science Foundation of China (Grant No. 41101567) to ZW. The authors also thank the financial award from State Scholarship Fund of China Scholarship Council (File No. 201308420277) to support the research at UCSB (to ZW). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.