深圳茅洲河下游沉积物中多环芳烃来源分析与生态风险

Source identification and ecological risk assessment of polycyclic aromatic hydrocarbons in sediments in the downstream Maozhou River, Shenzhen, China

为研究茅洲河沉积物中多环芳烃的来源与生态风险,于2016年8月采集茅洲河柱状沉积物9根,使用GC-MS分析了16种多环芳烃(PAHs)。结果表明,沉积物中ΣPAHs范围为:453.7～998.1 ng·g-1,平均含量为708.3 ng·g-1,呈入海口与上游浓度较高、中下游浓度相对较低的分布特征。0～0.5 m层、0.5～1.0 m层和1.0～1.5 m层16种多环芳烃浓度分别为(855.4±81.3)、(739.7±70.3)ng·g-1和(570.3±54.2)ng·g-1。多环芳烃环数呈4环>5环>6环>3环>2环变化趋势。茅洲河0～0.5 m沉积物中多环芳烃主要来自于草、木和煤等燃烧源的不完全燃烧,0.5～1.0 m层主要来源于不完全燃烧和混合来源,1.0～1.5 m层主要来源于混合源,其次为燃烧源,且出现了石油源。研究区内沉积物中苯并(b)荧蒽(BbF)、苯并(k)荧蒽(BkF)、茚并(1,2,3～cd)芘(IcdP)和苯并(g,h,i)芘(BghiP)在各点位均有检出,因而可能会对生物产生毒害作用,其余组分在各采样点的含量均低于有效应区间低值(ERL),对生物几乎无毒副作用或毒副作用不明显,生物有害效应概率<10%。

To identify the sources and conduct ecological risk assessment of polycyclic aromatic hydrocarbons(PAHs)in sediment cores from the Maozhou River,nine columnar sediment samples were collected in August2016.Sixteen kinds of PAHs were identified using gas chromatography-mass spectrometry.The results demonstrated that the range ofΣPAHs in the sediments were453.7~998.1ng·g^-1,and the average content was708.3ng·g^-1.The concentration was highly distributed upstream and in the estuary,but low in the middle and downstream.The concentrations ofΣPAHs content of0~0.5,0.5~1.0m,and1.0~1.5m were(855.4±81.3),(739.7±70.3)ng·g^-1,and(570.3±54.2)ng·g^-1,respectively.The number of PAH rings were in the order of4-ring>5-ring>6-ring>3-ring>2-ring.Source identification showed that the PAHs in0~0.5m of sediments came from the incomplete combustion of grass,wood,and coal;those in0.5~1.0m of sediments came from incomplete combustion and mixed sources;and those in1.0~1.5m of sediments were mainly from mixed sources,followed by those arising from fossil fuels/petroleum product combustion.BbF,BkF,IcdP,and BghiP,detected at all sample sites,could have toxic effects on living organisms.The concentrations of other components from all sample sites were lower than the ERL value;hence,these were rarely toxic or are non-toxic.The probability of harmful biological effects was less than10%.