W6 PM Environmental Changes in Response to China's Economic Expansion
Wednesday, 16 November 2005: 1:50 PM - 5:30 PM in 324-326

(PEN-1117-819209) Organic chlorinate pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in the Xijiang River, China.

Peng, Ping'an¹, Deng, Hongmei ^{1, 2}, Song, Jianzhong¹, ¹ State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, Guangdong, P.R.China² Graduate School of Chinese Academy of Sciences, Beijing, P.R.China

ABSTRACT- Xijiang River is the major branch of the Pearl River, covering an area of 353,120 km2 , which takes 77.8% of area of Pearl River. The rapidly developing in industry and agriculture and massive use of chemicals in last two decades had caused serious pollution problems, which have adversely influenced the air and water quality in this area. It is important to quantify the flux and the particle-water distributions of organic chlorinate pesticides (OCPs) and PAHs in Xijiang River that may help us to estimate the trend of pollution and thereby to provide the effective methods to control the POPs pollution in this area. In this study,we seasonally collected the upper, middle and lower part of water column samples at Gaoyao hydrological station of the Xijiang River. The Upper, middle and lower Samples were separated into particulate (Cp) and dissolved (Cw) phase using 0.7um glass fiber filters. Liquid and particular phase were both analyzed for OCPs and PAHs. Total OCPs concentration varies seasonally from 0.24 to 3.81 ng/l for particular (Cp), from 1.31to13.68 ng/l for liquid (Cw), while total PAHs concentration varies from 101.7 to 499.1 ng/l (Cp), from 3.74 to 110.3 ng/l (Cw). It is clear that the total OCPs and PAHs concentration in high flow season, summer, was higher than in low flow, winter. The results also showed that the concentration of these selected pollutants in the particle phase was higher than those in dissolved phase. Among HCHs (HCHs=a-HCH+b-HCH+g-HCH+d-HCH), the predominance of b-HCH of total HCHs was clearly observed both in the particle and dissolved phase. The ratios of DDT/(DDE+DDD) for the Gaoyao water column samples demonstrate that such chemicals were polluted in this region in recent times. The predominant PAHs in the particle phase and dissolved phase are all 3-4 ring PAHs originate from combustion of fossil fuels. Take HCHs and DDTs as an example, the flux of these OCPs were 92.3 and 71.1kg/annual respectively. It showed the OCPs concentration was not high in comparison with other places in the world. However, the flux of anthracene(three ring of PAHs) ,benzo[a]pyrene (four ring of PAHs) and benzo[g,h,i]perylene (six ring of PAHs) were 4091.1,5104.2 and 1390.4kg/annual respectively, it was much higher than it reported in the Mississippi River.

Key words: OCPs, PAHs, Flux, Xijiang River