珠江广州河段重污染沉积物中多环芳烃赋存状态初步研究  

Particle-scale distribution of polycyclic aromatic hydrocarbons in highly contaminated sediments of the Guangzhou channel of the Pearl River

作　　者：吴启航[1] 麦碧娴[1] 杨清书[1] 彭平安[1] 傅家谟[1] 

机构地区：[1]中国科学院广州地球化学研究所有机地球化学国家重点实验室

出　　处：《地球化学》2004年第1期37-45,共9页Geochimica

基　　金：国家自然科学基金(40272129);广东省自然科学基金(010504)

摘　　要：对珠江广州河段重污染沉积物进行粒度分级(>500μm、500～220μm、220～63μm、63～22μm和<22μm),每个粒级的样品进行重液分离,收集轻组分(有机质)和重组分(主要为无机矿物及无定型有机质)。在显微镜下对沉积物中不同粒径轻重组分的吸附剂进行鉴定,对其中的多环芳烃进行定量分析,结果表明,白鹅潭样品中有机质占总质量的9.10%,富集了81.55%的多环芳烃,无机矿物和无定型有机质占90.92%,富集了18.45%的多环芳烃;黄埔样品中有机质占总质量的8.95%,富集了56.50%的多环芳烃,无机矿物和无定型有机质占91.15%,富集了43.50%的多环芳烃。轻组分中的有机吸附剂对多环芳烃的富集能力比重组分无机矿物和无定型有机质高1～2个数量级,轻组分有机吸附剂中焦碳和碳黑富集能力较高,植物碎屑较低。总有机碳和碳黑的含量与多环芳烃的富集能力没有明显的相关性。Wet sieving is performed to separate the sediments into five size fr actions (>500 ìm, 500～220 ìm, 220～63 ìm, 63～22 ìm, and < 22 ìm) and furt her into low (< 1.8 g/cm3) and high (> 1.8 g/cm3) density fractions using a cesi um chloride solution with a specific gravity of 1.8 g/cm3. These geosorbents are characterized under microscope. Each of these size and density fractions is the n analyzed for polycyclic aromatic hydrocarbons (PAHs). The results show that th e organic geosorbents of sediments from Baietan constitute 9.10%of the sediment mass, but contain 81.55%of total PAHs; inorganic sorbents and amorphous organi c matter constitute 90.92%of the sediment mass, but contain only 18.45%of tota l PAHs. In Huangpu sample, organic sorbents constitute 8.95%of sediment mass, b ut contain 56.50%of total PAHs; inorganic sorbents and amorphous organic matter constitute 91.15%of sediment mass, but contain 43.50%of total PAHs. The capac ity of sorption of PAHs of organic sorbents are 1～2 orders of magnitude higher than inorganic sorbents and amorphous organic matter in the Guangzhou channel se diments. Carbon soot and coke particles have higher capacity of sorption for PAH s than vegetal debris. The results also show that the PAHs concentration in orga nic geosorbents is not significantly correlated with the content of total organi c carbon and black carbon.

关 键 词：沉积物 多环芳烃 吸附剂 无定型有机质 污染 珠江 

分 类 号：P593[天文地球—地球化学] P512.2[天文地球—地质学]