...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The Science of the Total Environment >Modeling metal bioaccumulation in a deposit-feeding polychaete from labile sediment fractions and from pore water
【24h】

Modeling metal bioaccumulation in a deposit-feeding polychaete from labile sediment fractions and from pore water

机译：从不稳定的沉积物部分和孔隙水中模拟沉积生物中的金属生物富集

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Estuarine sediments are often highly enriched in particle-reactive metal contaminants and because aquatic animals have often been shown to acquire metals predominantly from their diet, benthic animals feeding on deposited or resuspended sediments may also accumulate metals through this uptake pathway. Laboratory experiments were performed in which the surface deposit-feeding polychaete, Nereis succinea, was exposed to As( + 5), Cd, and Cr( + 3) in pore water or in estuarine sediments with and without enrichment with algal debris. These experiments generated metal uptake parameters (assimilation efficiency of ingested metal [AE], uptake rate constant of dissolved metal, efflux rate constants following dietary or aqueous metal exposures) used in a kinetic model of metal bioaccumulation. The model showed that >97% of the body burden of these metals is accumulated through ingested sediment. The kinetic model was further modified to consider the geochemical fractionation of the metals in the sediments because metals bound to some fractions were shown to be unavailable to these polychaetes. The modified model substituted the AE term for each metal by the percentage of metal extracted in neutral and weak acid exchangeable fractions (termed "carbonex" fraction) multiplied by the slope of the regression between the metal AE and its fractionation in carbonex. The modified model generated predictions of As, Cd, and Cr body burdens in polychaetes at three different estuarine sites that matched independent field observations at these sites (r~2 = 0.84 for sediments without organic enrichment, r~2 = 0.87 with organic enrichment). Model predictions that relied on total metal concentrations showed weaker relationships (r~2 = 0.11-0.50). This study adds to the evidence for the dominance of dietary uptake of metals in aquatic animals and identifies a key sedimentary fraction of metals that can account for bioavailability of sediment-bound metals.
机译：河口沉积物通常富含与颗粒反应的金属污染物，而且由于经常显示水生动物主要从其饮食中获取金属，因此以沉积或重悬沉积物为食的底栖动物也可能通过这种吸收途径积聚金属。进行了实验室实验，其中，在有或没有藻类碎片富集的情况下，将表面沉积物喂食的多毛沙棘（Nereis succinea）暴露于孔隙水或河口沉积物中的As（+5），Cd和Cr（+3）。这些实验产生了用于金属生物累积动力学模型的金属吸收参数（摄入金属的吸收效率[AE]，溶解金属的吸收速率常数，饮食或含水金属暴露后的流出速率常数）。该模型显示，这些金属中> 97％的人体负担是通过摄入的沉积物积累的。进一步修改了动力学模型，以考虑沉积物中金属的地球化学分馏，因为与某些馏分结合的金属被证明对这些多壳动物是不可用的。修改后的模型用每种在中性和弱酸可交换馏分（称为“ carbonex”馏分）中提取的金属的百分比乘以金属AE及其在carbonex中的馏分之间的回归斜率来代替每种金属的AE项。修改后的模型生成了对三个不同河口站点多壳动物中As，Cd和Cr体负荷的预测，与这些站点的独立现场观测结果相匹配（对于没有有机富集的沉积物，r〜2 = 0.84；对于有机富​​集，r〜2 = 0.87） 。依赖于总金属浓度的模型预测显示出较弱的关系（r〜2 = 0.11-0.50）。这项研究为在水生动物中饮食摄取金属的优势提供了证据，并确定了可以解释与沉积物结合的金属的生物利用度的金属的关键沉积部分。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号