广西主要贝类养殖区重金属含量分布特征及污染评价

Distribution Characteristics and Pollution Evaluation of Heavy Metals from Major Shellfish Culture Areas of Guangxi

为探究广西主要贝类养殖区重金属含量的分布状况及污染水平,依据2016-2018年广西主要贝类养殖区的海水、表层沉积物及生物体中重金属元素(Cu、Pb、Zn、Cd、Hg、As)的调查分析数据,分别采用单因子污染指数(P_i)法、地积累指数(I_(geo))法和生物富集系数(Bioconcentration Factors, BCF)对养殖区重金属进行污染评价。结果表明:海水中各重金属的含量分布为Zn>Cu>As>Pb>Cd>Hg,污染程度为Cu>Hg>Zn=Pb>Cd>As;沉积物中各重金属的含量分布为Zn>Cu>Pb>As>Cd>Hg,污染程度为As>Cd>Pb>Hg>Cu=Zn;近江牡蛎(Crassostrea rivularis)贝体中各重金属的含量分布为Zn>Cu>Cd>As>Pb>Hg,污染程度为Zn>Cu>Cd>Pb>Hg>As,生物富集能力为Zn>Cu>Cd>Hg>As>Pb。由此可知,广西主要贝类养殖区的海水水质较好,属于本底水平;沉积物环境属于较清洁水平,适合贝类养殖;生物体中重金属存在不同程度的污染,其中Zn、Cu和Cd的富集积累现象较显著,应引起重视。

In order to explore the distribution and pollution level of heavy metal content in major shellfish culture areas of Guangxi,based on the investigation and analysis data of heavy metal elements(Cu,Pb,Zn,Cd,Hg,As)in seawater,surface sediments and organisms of major shellfish culture areas of Guangxi during 2016-2018,the single factor index P i method,geo-accumulation index I geo method and Bioconcentration Factors(BCF)were used to evaluate the pollution of heavy metals in culture areas.The results show that the content distribution of all heavy metals in seawater is Zn>Cu>As>Pb>Cd>Hg,and the pollution degree is Cu>Hg>Zn=Pb>Cd>As.The content distribution of heavy metals in sediments is Zn>Cu>Pb>As>Cd>Hg,and the pollution degree is As>Cd>Pb>Hg>Cu=Zn.The contents of heavy metals in the shellfish of Crassostrea rivularis is Zn>Cu>Cd>As>Pb>Hg,the pollution degree is Zn>Cu>Cd>Pb>Hg>As,and the bioaccumulation ability was Zn>Cu>Cd>Hg>As>Pb.It can be seen that the seawater quality of the main shellfish culture areas in Guangxi is better,which belongs to the background level.The sediment environment belongs to relatively clean level and suitable for shellfish culture.There are different degrees of pollution of heavy metals in organisms,among which the accumulation of Zn,Cu and Cd is more significant,which should be paid attention to.