论文部分内容阅读
本文的主要目的为，通过对具不同ＡＶＳ含量的沉积物的金属加标实验和膜渗透平衡交换孔隙水采样技术，探讨孔隙水中二价有毒金属浓度对不同沉积物ＡＶＳ含量的化学响应关系和沉积物－孔隙水系统中二价有毒金属在固、液两相间的地球化学分配机制，并以此揭示在ＡＶＳ作用下，沉积物中二价微量金属的化学活动牲和生物可获得性。研究结果表明，用于加标实验的具不同硫化物含量的沉积物基质中，固相沉积物对镉、锌的吸收容量依ＡＶＳ含量而异，如按摩尔浓度计，固相沉积物对铺或锌的吸收容量与ＡＶＳ大致相等。当沉积物中与酸解硫化物同步被提取的金属铺或锌对ＡＶＳ的摩尔比，［ＳＥＭ］／［ＡＶＳ］小于１时，孔隙水中辐或锌难于被检出；而［ＳＥＭ］／［ＡＶＳ］大于１时，沉积物中镉或锌开始表现出强烈的化学活动性，它们在孔隙水中的浓度开始跟随总量浓度变化而变化。［ＳＥＭ］／［ＡＶＳ］＝１，似乎是判断缺氧海洋沉积物中二价有毒金属是否具有化学活动性的临界点。因此，ＡＶＳ归一化沉积物中的二价有毒金属（［ＳＥＭ］／［ＡＶＳ］摩尔比）被证明是一种方便直观地反映沉积物中二价有毒金属化学活动性的浓度表达方式，进而可被直接应用于金属沾污沉积物毒性或沉积物环境质量的评价。
The main purpose of this paper is to investigate the chemical response relationship and deposition of AVS in different sediments by metal spike test and membrane osmotic balance exchange pore water sampling with different concentrations of AVS in pore water Geochemical distribution mechanism of bivalent toxic metals in solid-liquid two-phase in pore-water systems, and to reveal the chemical activity and bioavailability of bivalent trace metals in sediments under the action of AVS. The results show that the adsorption capacity of Cd and Zn in sediment matrix with different sulfide content used for spiking experiment varies with AVS content, such as molar concentration, Or zinc absorption capacity and AVS roughly equal. When [SEM] / [AVS] is less than 1, the molar ratio of metal or zinc to AVS in the sediment extracted simultaneously with acid-desulfurization is less than 1 in the pore water, and the [SEM] / [ AVS] is greater than 1, cadmium or zinc in sediments begin to show strong chemical activity, their pore water concentration began to follow the total concentration changes. [SEM] / [AVS] = 1 seems to be a critical point to judge whether the bivalent toxic metals in the anoxic marine sediments have chemical activity. Therefore, the bivalent toxic metals ([SEM] / [AVS] molar ratios) in AVS normalized sediments proved to be a concentration expression that is convenient and intuitive to reflect the chemical activity of divalent toxic metals in sediments and thus It can be directly applied to the evaluation of the toxicity of metal-contaminated sediments or the environmental quality of sediments.