4种海洋贝类对水体中Pb的富集规律

The research of lead bioaccumulation in four species of seashell

为了研究泥蚶、菲律宾蛤、缢蛏和单齿螺等海洋贝类对海水中Pb的富集规律,本文在设置Pb质量浓度分别为0.001 0,0.003 5,0.006 0,0.011 0,0.026 0和0.051 0mg/L 6个试验组中,采用半静水法进行泥蚶、菲律宾蛤、缢蛏和单齿螺对海水中Pb的富集试验,分别在0,1,3,5,10,15,20,25和30d时取出部分贝类用微波消解-原子吸收光谱法测定Pb含量,并探讨了贝类对Pb的富集机制,比较了不同贝类对Pb的富集能力。实验结果表明:4种贝类均表现出了对Pb有一定的富集效应。水体中Pb质量浓度达到0.003 5mg/L时,泥蚶对Pb富集明显;水体中Pb质量浓度达到0.006 0mg/L时,菲律宾蛤对Pb富集明显。水体中Pb质量浓度达到0.011 0mg/L时,缢蛏和单齿螺对Pb富集明显。总体上,贝类体内重金属含量随着水体中Pb质量浓度和富集时间的增加而增加。在Pb质量浓度低于0.051mg/L的所有试验组中,时间越长,贝类体内富集的Pb含量越高,但在3d左右时,贝类体内富集的Pb含量却出现低值。

In the present study, the bioaccumulation of lead in four species of seashell including Tegillarca granos , Ruditapes philippinarum , Sinonovacula constricat canarck and Monodonta labio were investigated in a semi-static system. The seashell were cultivated in seawater contaminated with different lead concentrations （0.001 0,0.003 5,0. 006 0,0.0110,0.026 0,0.0510 mg/L, respectively）. The content of Pb was analyzed in muscle tissue using atomic absorption spectrometry with microwave digestion in 0, 1, 3, 5, 10, 15, 20, 25 and 30 d, respectively. The results indicated that the four species of seashell could accumulate lead from aquatic environment. The bioaccumulation of Tegillarca granosa was obvious while the concentration of lead in seawater was higher than 0. 003 5 mg/L. The lead concentration in Monodonta labio increased significantly while the concentration of lead in seawater was higher than 0. 006 mg/L. Similarly, the lead content in Ruditapes philippinarum and Sinonovacula constricat canarck exhibited significant increases while the concentration of lead in seawater was higher than 0. 011 mg/L. As a whole, the levels of Pb in seashell increased with the increase of those in seawater and the enrichment time. While the coneentraion of lead in seawater was lower than 0. 051 mg/L, the levels of lead in seashell showed significant decrease in 3 d and continued to increase after 5~10 d. Finally, the mechanisms of seashell response to lead enrichment were also investigated.