广西珍珠湾红树林湿地沉积物烃类物质的分布及来源解析

Distribution and source analysis of hydrocarbons in sediments of Zhenzhu Bay Mangrove Wetland in Guangxi

为研究广西珍珠湾红树林湿地表层沉积物有机质中烃类化合物的分布特征及来源,于2021年9月采集珍珠湾红树林湿地表层沉积物样品13件,对沉积物中的正构烷烃和多环芳烃(PAHs)进行测试分析。分析结果表明:珍珠湾红树林湿地表层沉积物中正构烷烃的含量(干重)为362.17~10 390.72 ng/g,PAHs含量(干重)为7.76~28.06 ng/g,总体处于含量较低的水平;特征参数比值法分析结果显示,正构烷烃主要来源于陆源非浮水草本植物,未受石油及其衍生品的污染;PAHs具有大分子化合物占优势的特征,同分异构体比值法分析结果表明PAHs的潜在来源有石油、石油燃烧和煤炭草木燃烧,主成分分析-多元线性回归分析结果表明,其来源主要为混合燃烧源(>52%),其次为石油污染源;应用效应区间低/中值法对PAHs进行生态风险评价,结果表明PAHs生态风险处于较低水平。

To study the distribution characteristics and sources of hydrocarbons in the surface sediments of Zhen-zhu Bay Mangrove Wetland in Guangxi,South China,13 surface sediments of the wetland were collected in September 2021 to test and analyze the normal alkanes and polycyclic aromatic hydrocarbons(PAHs)in the sedi-ments.Results show that the content of n-alkanes(dry weight)in the surface sediments of the area was 362.17~10390.72 ng/g,and the content of PAHs(dry weight)was 7.76~28.06 ng/g,which was generally at a low level.The n-alkanes were mainly come from terrestrial non-floating herbs and were not polluted by petroleum and its derivatives;PAHs were characteristic of dominant macromolecular compounds as shown in the characteristic parameter ratio method.The potential sources of PAHs were pertroleum,pertroleum combustion,and coal vegeta-tion combustion as indicated in the isomer ratio method.In addition,the main source of PAHs was mixed combus-tion source(>52%),followed by oil pollution source,as revealed by the principal component analysis/linear re-gression analysis model(PCA-MLR).At last,the ecological risk of PAHs was at a low level as determined in the ecological risk evaluation of PAHs by the effect interval low/median method.