摘要
本文提出了东海沉积物间隙水中溶解硅酸盐和硫酸盐的“扩散-平流-反应”模式。研究结果表明,由于间隙水受到硅酸盐溶解、吸附和沉淀不同体系的控制,因而间隙水中的硅酸盐具有三种不同形式的垂直分布,并从模式中得到了上述反应的反应常数,其中E柱硅溶解的一级动力学反应常数为0.00l 42a^(-1)。首次发现了东海沉积物间隙水中硅酸盐指数下降的垂直分布规律,并从数学模式上进行了处理。本文还研完了由于有机质还原sO_4^(2-)而产生的硫酸盐指数下降垂直分布,提出其模式,结果表明,SO_4^(2-)还原最大速率发生在沉积物-水界面附近,每年可达lmmo1/dm^3。
The models of 'diffusion-advection-reaction' of dissolved silicate and sulfate in sediment interstitial waters of the East China Sea are given in this paper. The maximum profiles of dissolved silicate in interstitial water were found. The main diagenetic reactions are dissolution of silicate, adsorption of clay mineral and precipitation of authigenic mineral. The reaction rate constants obtained from the models for silica dissolution is 0,001 42 a-1 at site E (Fig. 4). Dissolution of silica take place in surface sediment (above 10cm). The exponential decrease of vertical distribution of dissolved silicate was found for the first time in sediment interstitial water of the East China Sea (Fig.5), so adsorption and' precipitation of dissolved silicate are the controlling reactions of removal. Equilibrium concentration of dissolved silicate precipitation is 235 μmol/L at site B. This paper also gives the model of sulfate exponential decrese of vertical distribution because of the sulfate reduction by organic matter degradation. The rate constants for reaction are found to be 0.00123 a-1 and 0.000 93 a-1 at site C and F, respectively (Fig.6), the maximum rate constants being 1 μmol/ L·a near the surface sediment (0-10cm).This paper has expounded for the first time the process of chemical element early dia-genesis in kinetic principle in the East China Sea and some special distribution rules of dissolved silicate.
出处
《海洋科学》
CAS
CSCD
北大核心
1991年第1期27-34,共8页
Marine Sciences
基金
国家自然科学基金
编号:4870284
关键词
东海
沉积物
间隙水
硫酸盐
硅酸盐
Models of 'diffusion-advection-reaction', Silicate, Sulfate, Interstitial water, East China Sea