摘要
于1988年6—7月在辽东湾进行了调查,对其沉积物间隙水中Fe^(2+),Mn^(2+)及有关参数的测定结果及相关分析表明,铁、锰平面与垂直分布类型的不同是由于Fe^(2+),Mn^(2+)氧化还原速率、扩散速度及控制体系不同的综合结果,得出Fe(Ⅱ,L)+S_2^(2-)→FeS_2(s)和Mn(Ⅳ,s)→Mn(Ⅱ,L)是控制辽东湾间隙水中Fe^(2+),Mn^(2+)浓度的主要体系,并用氧化还原界面层的一种简单模式讨论了铁、锰转移与其浓度-深度分布形状的关系。本文还应用Fick第一定律直接计算了沉积物-海水界面间铁、锰扩散转移通量。
This paper deals with the redox process and chemical diagenesis of iron and manganese in sediment interstitial waters of Liaodong Bay, Bohai Sea. Eight cores from this Bay were obtained in June and July 1988. The concentrations of Fe2+, Mn2+ and SO2-4 in interstitial waters and the parameters of sediments such as pH, Eh and Es*, were determined. The main results are as follows:1.Horizontal distributions of Fe2+ and Mn2+ appear to decrease and increase with the raising of latitude. The interstitial waters are apprently richer in Mn2+ than the overlying seawater. The preliminary result indicates that concentrations of Mn2+ are effected by the redox potential of sediment, but those of Fe2+ are not. The vertical profiles of Fe2+ show that there is a maximum of Fe2+ concentrations in 5-25cm depth of cores, but the maximum of Mn2+ concentrations is found on the interface of sediment-water. This demonstrates that the addition and removal of Fe2+ and Mn2+ in interstitial waters are different.2. From the concentration gradients of iron and manganese in interstitial water within the near-surface zone, the diffusion fluxes across the sediment-seawater interface were calculated by means of the Fick's first law modified for sediment. Fe2+ and Mn2+ are provided from sediment to overlying water. The fluxes of Fe2+ and Mn2+ are 62.6μg/(m2·d) and 994.3μg/(m2·d), respectively.3. Fe2+ vs. Mn2+ and Mn2+ vs. SO2-4 vary in positive correlation, but Fe2+ vs. SO2-4 and ∑ vs. Fe2+ in negative correlation. The studies on chemical diagenesis show that the reactions of Fe(Ⅱ,L) + S2-2→FeS2(s) and Mn(Ⅳ,s)→Mn(Ⅱ,L) are the controlling reactions of Fe2+ and Mn2+ in interstitial waters of Liaodong Bay.4. A simple model is proposed to describe the mass transfer of iron and manganese in the zone of redox boundary. The shapes of concentration-depth profiles of Fe2+ and Mn2+ in interstitial waters of Liaodong Bay are discussed in terms of the model modified. The shapes of vertical profiles of Fe2+ and Mn2+ are resulted from the comprehensive consequences of different rates of redox, diffusion and distinct controlling systems.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
1991年第5期451-457,共7页
Oceanologia Et Limnologia Sinica
基金
国家自然科学基金 编号:4870284
