摘要
制备了一种能够选择性识别Cd^(2+)的平面传感膜;该膜具有响应速度快(<20 s)、准确性高及稳定性好等特点。利用该传感膜制备的Cd^(2+)平面光极系统,应用于生物扰动存在的水/沉积物体系中,根据体系垂直剖面Cd^(2+)的分布及迁移情况,研究颤蚓生物扰动对上覆水中Cd^(2+)向沉积物迁移的影响。研究发现:制备的Cd^(2+)平面光极系统可以反映出上覆水中Cd^(2+)向沉积物迁移的过程。无生物扰动时,沉积物仅表层及水/沉积物界面下2 cm深度范围内第1~3 d的Cd^(2+)浓度略有升高,随后趋于稳定;深度超过2 cm的沉积物Cd^(2+)浓度几乎不变(同背景浓度)。有生物扰动时,深度约5 cm范围内的沉积物中Cd^(2+)浓度显著增加,深度越浅的沉积物中的Cd^(2+)浓度增加越快,深度超过5 cm的沉积物中Cd^(2+)浓度基本不变。与无生物相比,颤蚓扰动可以显著促进Cd^(2+)由上覆水中向沉积物的迁移。
A Cd^2＋ plane sensing membrane has been developed, and the membrane has advantages including a short response time （ 〈20 s） , precise and good stability. With the help of camera, the sensor can directly show the variability in the distribution and migration of Cd^2＋ vertical profile in water/sediment system. The research indi-cates that the planar optode applied to a simulated water/sediment microcosm can reflect the migration of Cd^2＋ from water to Sediment. In addition, in the absence of bioturbation, the concentration of Cd^2＋distributed in the interface and the district within the depth of 2 cm from the interface of water/sediment was slightly increased in the first three days, and then tended to be stable. The concentration of Cd^2＋distributed in the district deeper than 2 cm from the interface of water/sediment remained constantly. Under the bioturbation, the concentration of Cd^2＋ distributed in the district deeper than 5 cm from the interface of water/sediment was increased dramatically. The amount of the Cd^2＋ increased was inversely proportional with the depth, the concentration of Cd^2＋ distributed in the district deeper than 5 cm from the interface of water/sediment was remained constantly. Compared with the absence of bioturba-tion, tubificid biological disturbance can significantly promote the migration of Cd^2＋ from water to sediment.
出处
《科学技术与工程》
北大核心
2016年第21期125-129,165,共6页
Science Technology and Engineering
