乌江渡沉积物磷的污染特征及其对河流筑坝的响应  

Characteristics of Phosphorus in Sediment of the Wujiangdu Reservoir and Its Responses to Damming

作　　者：胡鑫平 李庞义 王敬富[1] 杨海全[1] 郭建阳[1] HU Xinping;LI Pangyi;WANG Jingfu;YANG Haiquan;GUO Jianyang(State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Environmental Science&Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550081 [2]中国科学院大学,北京100049 [3]华中科技大学资源与环境学院,武汉430074

出　　处：《地球与环境》2022年第6期805-812,共8页Earth and Environment

基　　金：国家自然科学基金项目(41877406);国家自然科学基金-贵州省喀斯特科学研究中心联合项目(U1612441);贵州省湖泊水环境科技创新基地中央引导地方科技发展资金项目(黔科中引地[2021]4028)。

摘　　要：受息烽河输入的影响,乌江渡水库的磷污染问题一直备受关注,但水库上游水体磷的释放以及河流筑坝对水库磷污染的影响却没有引起太多的重视。本文通过对表层沉积物和沉积物柱芯中磷及其形态的分析,研究乌江渡沉积物磷的污染现状和历史变化趋势及其对河流筑坝的响应。结果表明:1)乌江渡水库沉积物磷污染现已非常严重,远高于国内其他湖库;2)乌江渡沉积物磷含量从上游至下游有递增的趋势,且主要由NaOH-P的增加所致;3)乌江渡沉积物磷的空间变化可能源于不同粒径颗粒物或藻类的沿程沉降,也可能源于水体中Fe^(2+)被氧化后引起磷的沿程沉降,但真实原因还需要进一步的证实。这说明上游水库滞留在沉积物中的磷部分可能重新释放出来,导致乌江渡水库中上游沉积物磷的污染也相当严重。Phosphorus pollution in the Wujiangdu Reservoir has been a matter of serious concern,due to the input of phosphorus from Xifeng River.However,the release of phosphorus from the upstream and the influence of damming on the phosphorus pollution in the Wujiangdu Reservoir have little concerned.Based on the analysis of phosphorus and its geochemical forms in surface sediments and sediment cores,the current situation and historical trend of phosphorus in Wujiangdu sediments,as well as its response to river damming,were investigated.The results showed that:1)the phosphorus pollution in sediments of the Wujiangdu Reservoir was highly serious,which is much more serious than that of other lakes or reservoirs in China;2)phosphorus contents in sediments of the Wujiangdu Reservoir increased from the upstream to the downstream,mainly caused by the increase in NaOH-P in the sediments;3)spatial variation of phosphorus in sediments may be caused by the settlement of particles or algae along the flow direction,or by the deposition of phosphorus caused by the oxidation of Fe^(2+) in water,but the real reason needs further confirmation.This study indicated that sedimentary phosphorus detained in the upper reservoir may be released again,leading to the serious sedimentary pollution of phosphorus in the upper and middle reaches of the Wujiangdu Reservoir.

关 键 词：磷 沉积记录 滞留效应 乌江渡水库 地球化学形态 

分 类 号：X52[环境科学与工程—环境工程]