南京有机污染风险区农田土壤多环芳烃污染状况研究

Polycyclic Aromatic Hydrocarbons in Farmland Soil around Risky Organic Contamination Areas in Nanjing

采集南京地区不同有机污染风险区农田表层土壤,用超快速液相色谱仪检测样品中15种EPA优控的多环芳烃(PAHs)含量。结果表明,被检农田土壤多环芳烃总量分布于306.0~1251.3μg kg^(-1)之间,均值682.0μg kg^(-1),四环以上高环多环芳烃占较大比例(>80%)。根据欧洲土壤质量标准,所检土壤样本已达污染水平。不同风险污染区农田土壤PAHs的含量由高至低为:钢铁工业区、有机垃圾处理区、化工工业区及炼油工业区。钢铁工业区附近主要的污染物为荧蒽、芘、屈和苯并[a]蒽,分别占到污染物总量的16%、13%、10%和10%。采用荧蒽/(荧蒽+芘)与茚并[1,2,3-cd]芘/(茚并[1,2,3-cd]芘+苯并[g,h,i]苝)比值对各地污染物来源进行分析,结果发现调查区域的PAHs污染物以燃烧源为主,生物质燃料为主要污染物,部分地区同时有石油燃烧污染。

Topsoil samples were collected from farmland around different risky organic contamination areas in Nanjing. Concentrations of 15 priority polycyclie aromatic hydrocarbons （PAHs） controlled by US Environmental Protection Agency （EPA） were analyzed using ultra fast liquid chromatography. Results showed that the sum of 15 PAHs from different sites ranged from 306.0 ·g kg-1 to 1251.3 ·g kg-1 with the average value of 682.0 μg kg-1. Over 80% of PAHs belonged to the high molecular weight group. According to Europe proposed classes of soil contamination, all samples in this study were contaminated by PAHs. Besides, the concentration of PAHs in soil around steel industrial zone was higher than that around refuse disposal area, chemical industrial and oil refining zone. The main compounds in soil around steel industrial area were fluoranthene, pyrene, chrysene and benz [a] anthracene, accounting for 16%, 13%, 10% and 10%, respectively. The numerical ratio of fluoranthene / （fluoranthene ＋ pyrene） and ideno （1,2,3-cd） pyrene / （Benzo [ghi]perylene＋ideno （1,2,3-ed） pyrene） was used as a tool for identifying and assessing pollution emission sources. It also indicated that biomass combustion study, and petroleum combustion was another main source in products contributed most to PAHs contamination in this some districts.