文蛤养殖水体中重金属Cu的安全限量值研究

摘要

The biological enrichment experiment of the metal Cu in Meretrix meretrix exposed to sediment was simulated using the semi-static two-compartment kinetic model under an established water-sediment-organism system by introducing the sediment factor.The kinetic parameters in the process of accumulation and elimination were obtained by nonlinear curve fitting.The uptake rate constant (k1),elimination rate constant (k2)and bioconcentration factors (BCF) were 71.18,0.03 and 4 283.86,respectively.It was found that the metal Cu concentration in M.meretrix exposed to sediment fit well with the two-compartment kinetic model.According to the two-compartment kinetic model,safety levels of Cu in M.meretrix farming water was 0.017 mg·L-1.The experimental results indicated that the semi-static two-compartment kinetic model was suitable for estimating the bioconcentration of the metal Cu in M.meretrix.Compared BCF obtained from test with that got from local surveys in M.meretrix fanning water,safety levels of Cu in M.meretrix in this study is higher than standards.%通过引入沉积物因子,构建海水-底泥-生物体体系,应用半静态双箱动力学模型在室内模拟了沉积物暴露条件下文蛤(Meretrix meretrix)对重金属Cu的生物富集实验.通过对富集与排出过程中文蛤体内重金属Cu的动态监测和监测结果的非线性拟合,得到了文蛤富集Cu的动力学参数:吸收速率常数k1为71.18、排出速率常数k2为0.03,生物富集系数(bioconc entrationfactors,BCF)平均值为4 283.86.对模型的拟合优度检验结果显示,沉积物暴露条件下文蛤对重金属Cu的生物富集数据符合双箱模型.根据双箱动力学模型推算出来的文蛤养殖水体中Cu的安全限量值为0.017 mg· L-1.实验结果表明,沉积物暴露条件下双箱动力学模型在一定条件下是可以应用于文蛤富集动力学研究的.通过对比室内模拟实验与实地调查所得BCF发现本研究得出的Cu的安全限量值略高于现有标准.