Atmospheric ammonia and particulate ammonium from agricultural sources in the North China Plain

Publication Type

Journal contribution (peer reviewed)

Authors

Shen, J., Liu, X., Zhang, Y., Fangmeier, A., Goulding, K., Zhang, F.

Year of publication

2011

Published in

Atmospheric Environment

Band/Volume

45/

DOI

10.1016/j.atmosenv.2011.02.031

Page (from - to)

5033-5041

Atmospheric ammonia (NH₃) and particulate ammonium (NH₄⁺) were measured using passive samplers and particulate samplers at four rural and two suburban sites in the North China Plain (NCP) from August 2006 to September 2009. The annual mean concentrations of NH₃ and NH₄⁺ in PM₁₀ across the sites were 15.6 and 12.4 μg m^-3, respectively. Higher concentrations of NH₃ and NH₄⁺ were found at the rural sites compared with the suburban sites. NH₃ concentrations were highest in summer and lowest in winter, showing positive correlations with N fertilizer application rates and temperature in each season. Particulate NH₄⁺ showed significant positive correlations with particulate SO₄^2- and NO₃^- at the six sites. The annual mean concentrations of secondary inorganic particles (sum of NH₄⁺, SO₄^2- and NO₃^-) accounted for 26.1-41.3% of the PM₁₀ concentration across all sites. The formation of inorganic NH₄⁺ particles was limited mainly by the availability of H₂SO₄ and HNO₃ and partly by NH₃. The total NH_x deposition in the NCP averaged 43.5 kg N ha^-1 yr^-1, accounting for 84.1% of the mean NH₃ emission intensity. The serious particulate NH₄⁺ pollution and high NH_x deposition suggest the urgency of reducing NH₃ emission from agricultural sources in the NCP. © 2011 Elsevier Ltd. All rights reserved.