天津潮间带泥螺（Bullacta exarata）对重金属镉的累积与释放特征

生物对重金属的累积与释放实验对研究生物修复、污染物生态毒性和环境风险评价有着十分重要的意义。通过对天津潮间带底栖生物泥螺进行室内镉累积与释放实验,研究了泥螺体和肝脏对镉的累积与释放特征。整个实验过程分为累积和释放两个阶段,实验样品经冷冻、干燥、研磨、混匀和称量后,采用原子吸收分光光度法进行测定。结果表明,泥螺对镉的累积周期为14 d,其身体和肝脏中镉的质量分数均呈现先升高后降低的趋势,在第7 d达到最大值,其中肝脏的累积能力要大于身体;泥螺对镉的释放周期为12 d,在第9 d趋于稳定。泥螺对镉的累积与释放不仅与其自身的生活习性有关,还与其栖息环境密切相关。在自然环境中,应当严格控制镉的人为输入,尤其是含镉工业废水的排放。

Accumulation and Elimination Characteristics of Heavy Metal Cadmium in Bullacta exarata from Intertidal Zone of Tianjin,China

Cadmium accumulation and elimination of organism have important influence on bioremediation,pollutant ecological toxicity and environment risk assessment.The characteristics of cadmium accumulation and elimination in Bullacta exarata＇ body and liver,which were from the intertidal zone of Tianjin,were studied in our laboratory.The entire experiment included two parts,accumulation and elimination.The samples were frozen,dried,grinded,blended and weighed,then measured by Atomic Absorption Spectrometry（AAS）.The result showed that the accumulation period was 14 d.The mass fractions of cadmium in body and liver were from high to low,the maximum was at 7 d.The accumulation in liver was greater than that in body.And,the depuration period was 12 d,the stable point was at 9 d.The accumulation of cadmium in Bullacta exarata related not only with their life behaviour but also with their habitats.In the natural environment,the human in-put of cadmium should be strictly controlled,particularly the discharge of the cadmium industrial waste water.