山东省南四湖表层水和沉积物中SCCPs赋存特征及风险评价

Characterization and Risk Assessment of SCCPs in Surface Water and Sediments of Nansi Lake,Shandong Province,China

短链氯化石蜡(SCCPs)具有良好的化学稳定性和热稳定性,被我国广泛用作金属加工中的润滑剂、密封剂,纺织品中的阻燃剂以及塑料中的增塑剂。但SCCPs的持久性、高毒性、长距离迁移特性和生物蓄积性会对生物体的肝脏、新陈代谢以及发育产生影响,对人类的健康具有潜在危害。目前SCCPs已广泛存在于环境中,然而对其在湖泊淡水环境中的赋存特征及风险评价仍缺乏系统的研究。本文采用GC-MS分析了南四湖表层水和表层沉积物中SCCPs的含量水平、组成特征,探讨了污染物的主要来源及潜在风险。结果表明:①表层水中SCCPs总浓度为53.9~1287.7 ng/L,沉积物中SCCPs总含量为609.9~113761.7 ng/g(以干质量计,下同)。南四湖表层水中SCCPs浓度的空间分布呈现北部较高、南部较低的特征,沉积物中SCCPs含量的空间分布呈现两端高、中间较低的特征。结合南四湖周边环境因素分析,这可能与周边码头船只使用的燃料排放、湖泊水动力、大坝工程以及工业农业生产有关。②C_(10)SCCPs和C_(13)SCCPs是南四湖表层水和沉积物中主要的碳链基团,表层水中Cl_(6)SCCPs、Cl7SCCPs和Cl_(9)SCCPs是主要氯同类物,沉积物中Cl_(6)SCCPs是主要氯同类物。③主成分分析结果表明,南四湖表层水和沉积物中SCCPs的来源关联性较弱,可能与环境条件、人类活动及周边地区生产使用不同种类的氯化石蜡产品等多种因素有关。④熵值法初步风险评估表明,南四湖表层水大部分取样点处于中风险,部分取样点处于高风险,RQ平均值为0.85,整体处于中风险等级。沉积物取样点大部分处于高风险,部分取样点处于中风险,RQ平均值为21.07,整体处于高风险等级。研究显示,南四湖SCCPs污染日益加重,表层水中SCCPs浓度处于中风险等级,沉积物中SCCPs含量总体上已处于高风险等级,需要引起特别的关注。

Short-chain chlorinated paraffins(SCCPs)have good chemical and thermal stability and are widely used in China as lubricants and sealants in metalworking,flame retardants in textiles and plasticizers in plastics.However,SCCPs are potentially hazardous to human health due to their persistence,high toxicity,long-range transport and bioaccumulation.They can affect the liver,metabolism and development of living organisms.Currenly,SCCPs are widely present in the environment.However,there is still a lack of systematic research on the characterization and risk assessment of SCCPs in lake freshwater environments.In this paper,GC-MS was used to analyze the content levels and compositional characteristics of SCCPs in the surface water and surface sediments of Nansi Lake,and to explore the main sources of pollutants and potential risks.The results showed that:(1)The total concentration of SCCPs in surface water ranged from 53.9 ng/L to 1,287.7 ng/L,and the total content of SCCPs in sediment ranged from 609.9 ng/g to 113,761.7 ng/g(on a dry mass basis,same below).The spatial distribution of SCCPs concentration in the surface water of Nansi Lake was high in the north and low in the south,and the spatial distribution of SCCPs concentration in sediments was high at both ends and low in the middle.In addition,combined with the analysis of the surrounding environmental factors,the main cause of SCCPS pollution in Nansi Lake may be related to the fuel emissions used by ships in the surrounding wharves,lake hydrodynamics,dam engineering,and industrial agricultural production.(2)C_(10)SCCPs and C_(13)SCCPs were the main carbon chain groups in surface water and sediments of Nansi Lake,Cl_(6)SCCPs,Cl7SCCPs and Cl_(9)SCCPs were the main chlorine analogs in surface water,and Cl_(6)SCCPs were the main chlorine analogs in sediments.(3)Principal component analysis results showed that the correlation between the sources of SCCPs in the surface water and sediments of Nansi Lake was weak,which might be related to a variety of factors,such as environmental conditions,human activities,and the production and use of different types of SCCPs products in the surrounding areas.(4)The preliminary risk assessment using the entropy value method shows that most of the surface water sampling points in South Lake Four are at medium risk,and some sampling points are at high risk.The average RQ is 0.85,and the risk is at medium level.Most of the sediment sampling sites are at high risk,some sampling sites are at medium risk.The average RQ value is 21.07,and the overall risk is high.The study shows that SCCPs pollution in Nansi Lake is increasing,the SCCPs concentration in the surface water is at a medium-risk level,and the content of SCCPs in the sediments is at a high-risk level overall,requiring special attention to be taken.