罗纳河中悬浮物质的痕量元素的研究

于1989年5月－1990年4月间，在罗纳河下游近河口处进行每月一次为期间个月的样品采集工作，并且样品用HNO3－HF－HCIO4湿法消化后，用原子吸收分光光度法测定了悬浮颗粒物中的Co，Cr，Cu，Mn和Pb含量。结果表明，在不同月份之间悬浮物中的痕量元素组成具有显著地差别，其中一些元素的浓度随流量的增加而减少，而另外一些似乎与流量之间没有显著的关联。在稳定体系的假设下，所估计的人文活动对痕量元素的贡献可占观测浓度的10％－50％。当与其它河流对比时，发现罗纳河中的颗粒态痕量元素的浓度明显高于那些受人文活动影响较小的体系，而与北美的河流系统接近，表明罗纳河流域的人文活动对河流中颗粒态痕量元素的影响是显著的。

CHEMICAL ANALYSES OF PARTICULATE TRACE ELEMENTS FROM THE RHONE RIVER

Suspended sediment samples from the Rhone River were collected monthly over the lower reaches (30km inland from the river mouth) from May, 1989 to April, 1990. The samples were digested with HNO₃-HF-HClO₄ and analyzed to determine concentrations of Co, Cu, Cr, Mn and Pb by atomic absorption spectrophotometry against international standards. The results show that the concentrations of the particulate trace metals are highly variable during the ?eld observation period, depending upon the water discharge, suspended sediment concentration and element of interest. Some of the metals (Cu, Pb and Mn) illustrated a concentration decrease in response to high water discharges, but others (Co and Cr) did not show any apparent relation with water flow. Using a steady state model, the contribution from anthropogenic activities was estimated to account for up to 50% or even higher for the particulate trace elements concentrations in the river, with the rest coming from the weathering and erosion over the drainage basin. During the ?eld observation of this study, the Rhone River suffered a serious drought period: water discharges in 1989-1990 represented only ca 70% for that of long tern average. The observed particulate trace elements concentrations may not necessarily account for a steady state and could be brased toward higher levels as a consequence of reduced water discharge and sediment load as well as extensive anthropogenic perturbations. A comparison with Chinese and other world large rivers such as the Zhujiang, Changjiang, Huanghe, St. Lawrence River and Lena etc. suggests that the particulate trace elements concentrations from the Rhone River are higher than those from larger and less disturbed systems, but similar to other European and North American rivers. However, the estimated background levels of particulate trace elements from the Rhone River are rather close to those suffering from weak human perturbations, indicating the signi?cant in?uence of human society in developed countries on riverine sediments composition and hence the elevated pollution discharge of the Rhone River into the Northwest Mediterranean Sea in the late 1980s and early 1990s.