摘要
利用一维简单模式讨论了黄河口水体中Cd的含量与氯度间的关系。结果表明,选用已有的某些常数,计算值与实(?)值间比较吻合,说明本模式是可用的;在利用Cd与Cl(或S)关系确定河流有效通量时,不仅要考虑某些物理化学参数,还应注意到水文参数的影响。
The distribution ot non-conservative element content in estuarine water can be expressed approximately with a simple one-dimensional model:Where R is the term ot variation for non-conservative element in mixing process, which can be written as:R=-Ks(C-θP/Kd) (2)in estuary for the adsorption and desorption of Cd from suspended matter. Here, K, is a rate constant, θmeans the amount of the suspended matter in sea water, P means the content of Cd in the suspended matter, and Kd, the distribution coefficient of Cd between suspended matter and water. Substituting R to eq. (1), with some assumption and boundary conditions of C = C0 at X - 0 and C = C m at X -Xm, associated with a conservative element C1 , we get the following solution:Based on the suspended matter content in the Huanghe River Estuary observed by Elbaz-Poulichet et al., combined with some other values, the calculated results show that the desorption process of Cd happens mainly in the area of low chlor-inity surrounding the river mouth, while in the area of higher chlorinity relatively low suspended matter content affects only slightly the desorption of Cd so the concentrations of Cd and Cl show almost a linear relation. The linear range changes with different Ks,Kx, and V, (Fig. 1- Fig. 4).With Ks = 1×10-4/s, Kx = 2×102m2/s and Vx = 0.1m/s for low water stage and Ks = 5×10-5/s, K, = 1×103m2/s and Vx = 0.5m/s for high water stage, the calculated values are in very good agreement with the measured values (Fig.5), which shows that the model is reliable. Meantime, it should be seen that when the effective flux of element in an estuary is estimated with the Cd-Cl (or S) relation, not only physico-chemical parameters, but also hydrologic parameters, should be considered.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
1992年第6期606-612,共7页
Oceanologia Et Limnologia Sinica
基金
自选课题
关键词
镉
黄河口
元素平衡
Cadmium, Huanghe River Estuary, Element balance in estuary.
