桂林水系沉积物中重金属的生物有效性研究  

Bioavailability of heavy metals in sediments in Guilin

作　　者：李振平[1] 张秦安 

机构地区：[1]桂林空军学院训练部,广西桂林541003

出　　处：《生态环境》2007年第3期744-747,共4页Ecology and Environmnet

基　　金：国家863项目(2003AA601060-02-04)

摘　　要：沉积物中重金属污染物对生态系统潜在危害的影响,已经引起研究者的极大关注,但对沉积物中重金属的生物有效性的研究还很少。首次以桂林水系沉积物为研究对象,通过酸化-吹气-吸收装置,用对氨基二甲基苯胺光度法测定沉积物中AVS含量,用原子吸收分光光度法测定SEM和间隙水中Cu、Pb、Zn、Cd、Ni含量,用原子荧光法测定Hg、As含量。以中华圆田螺(Cipangopaludian cathayensis)为受试物种,通过沉积物加标和长期暴露实验,分析田螺生长发育情况和体内重金属积累浓度。结果表明:[SEM]/[AVS]>1时,间隙水中七种元素总浓度大于3.0000μmol·L-1,重金属对田螺表现出毒性作用,且田螺的死亡率和体内重金属积累浓度随该比值的增大而增大;当[SEM]/[AVS]<1时,重金属对田螺无明显影响。[SEM]/[AVS]是判定沉积物重金属生物有效性的有效判据。该研究填补了桂林水系沉积物重金属数据的空白,为判定沉积物重金属污染程度提供了一种简便准确的方法。所研究水域沉积物重金属污染最严重的是桃花江,漓江次之,青狮潭水库污染最轻。Though researchers have paid much attention to the heavy metal pollutants in sediments that have potential harm to eco-system, they have seldom researched on bioavailability of heavy metals in sediments. In order to provide some scientific data for judging biological toxicity and bioavailability caused by heavy metals in sediments in Guilin, China, for the first time, the authors sampled sediments in different water areas in Guilin, and determined AVS by P-Amino dimethyl aniline dihydro chloride photometry through a set of acidification-ventilation-absorption AVS reaction unit, determined copper, lead, zinc, cadmium and nickel with tomic absorption spectrophotometry, mercury and arsenium with atomic fluorescence, and cipangopaludina cathayensis was selected as the tested species for bioavailability experiment. After long-term bioassay with micro-ecosystem, the growth and reproduction of cipangopaludina cathayensis and the bioaccumulation of heavy metals in their body were analyzed. The results showed that when the molar ratio of [SEM]/[AVS] is more than 1, the concentration of heavy metals in interstitial water was higher than 3.000 0 μmol·L^-1, so it cause biological toxicity to cipangopaludina cathayensis, both the death rate and the bioaccumulation of heavy metals increase with [SEM]/[AVS]; When [SEM]/[AVS] is less than 1, heavy metals have no obviously effect on cipangopaludina cathayensis; [SEM]/[AVS] can act as a criterion for judging the bioavailability of heavy metals in sediments. Our study supplied a gap of heavy metals data in Guilin, also provided a sort of convenient and accurate method for judging the degree of pollution caused by heavy metals. This study also revealed that Taohua River is the most severely contaminated river; Qingshitan Reservoir has the slightest pollution, and Lijiang River falls between them.

关 键 词：酸可挥发硫 同步提取金属 沉积物 间隙水 生物有效性 

分 类 号：X171.5[环境科学与工程—环境科学]