材料期刊网

为评估含有机污染物的湿沉降对区域水环境污染的贡献，在广州市3个采样点（海珠区、天河区和萝岗区）采集了2010年湿沉降样品（157个），并在天河点采集了12个干沉降、11个地表径流及10个气溶胶样品，并对其中指示化合物正构烷烃的浓度、来源和通量进行分析．正构烷烃（包括从C20—C34的15种同系物）总浓度范围为0．6—292μg·L－1；从季节上看，其在雨季（4—9月）的浓度低于旱季（1—3月和10—12月）．碳优势指数和主成分分析结果表明，广州市的正构烷烃主要来源于石油产品的消费（50％），暗示石油产品消耗是主要污染源；其次来自植物排放（38％）．此外，广州市在2010年有55±80 t（平均值±标准偏差）正构烷烃经干沉降和湿沉降至地表，其中湿沉降的贡献为39±80 t．同时，大约有224±296 t正构烷烃通过地表径流进入到珠江，反映了面源污染对区域水环境影响很大．因此，控制石油产品的消费和治理地表径流，是抑制面源污染、改善区域水环境的两个途径．

A total of 157 rainwater samples were collected from three locations ( Haizhu District, Tianhe District and Luogang District) in Guangzhou during the year of 2010. In addition, 12 dry deposition samples, 11 surface runoff samples and 10 aerosol samples were also collected at some of the sampling timepoints. The levels, sources and fluxes of n?alkanes were analyzed to evaluate the contribution of wet deposition containing organic pollutants to water quality. The concentrations of n?alkanes ( the sum of 15 congeners from C20 to C34 , labeled as ∑C20?34 ) ranged from 0. 6—292 μg·L-1 , with lower values during the wet weather season ( April?September ) than during the dry weather season ( January?March and October?December ) . Results from carbon preference index and principal components analysis showed n?alkanes in Guangzhou were mainly derived from residues of oil products ( 50%) . Emissions from plants were responsible for 38% of n?alkanes in wet deposition. In addition, the mean annual combined wet and dry deposition flux of n?alkanes in Guangzhou was 55 ± 80 t·a-1 with 39 ± 80 t·a-1 contributed by wet deposition. The mean annual surface runoff input of n?alkanes from Guangzhou to the Pearl River was estimated at 224±296 t·a-1, indicating the great impact of non?point sources on the aquatic environment. These findings suggested that reducing consumption of oil products and strengthening surface runoff treatment are two critical steps toward improving the regional water quality.