ATMOSPHERIC MERCURY MEASUREMENTS IN GUIYANG, P. R. CHINA

Xinbin Feng*, Jonas Sommar, Oliver Lindqvist (Department of Inorganic Chemistry, Göteborg University, S 412 96 Göteborg, Sweden)

Yetang Hong, Yongxuan Zhu (State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, P. R. China)

* Correspondence should be addressed, e-mail address: feng@inoc.chalmers.se, Telephone: +46-31-7722866, Fax: +46-31-7722853

Guiyang is a large city in southwest of China, where acid deposition occurs frequently due to coal combustion emissions. Currently about 4 Mt/a of coal are combusted for both industrial and domestic purposes in Guiyang. From July till November 1996, every single event of precipitation was gathered by a Teflon funnel that is connected to a 1 l Teflon bottle. The total and reactive mercury concentration of each sample was analyzed by using two stage amalgamation coupled with cold vapor atomic absorption spectrometry method (CVAAS). Two campaigns were carried out for measurements both total gaseous mercury (TGM) and gaseous divalent mercury (DGM). The first campaign was from 18 to 30 December, 1996, and the second one was from 13 to 29 October 1999. Total gaseous mercury was sampled and analyzed by an automated mercury analyzer-Gardis 1A with a time resolution of 10 min. Daily average gaseous divalent mercury was sampled by KCl coated denuders and analyzed by thermal desorption and AAS detection method. The average total mercury concentration of rain in Guiyang is 29.6 ng l-1 and the wet deposition rate is 34.6 mg m-2 a-1. The average TGM concentration in air in 1996 was 11.0 ng m-3 and in 1999 was 13.0 ng m-3. The increase rate of TGM in the air from 1996 to 1999 is 5.7% each year that is the same as the increase rate of coal consumption in Guiyang, which implies that coal combustion emission is the major source of mercury in the air in Guiyang. The average DGM concentration in the air in Guiyang is 454 pg m-3, which is much higher that background area.