Analysis Of Characteristic And Source Of Sulfur Isotope From Tributary Of The Yangtze River In Guizhou Province

The harmfulness of excess sulfate have prompted us to study the source of sulfate urgently.Comparing rivers sulfur isotope with water chemical means,we can find that the method of sulfur isotope can trace the different sources of sulfate in the river more clear.Studying the composition characteristics of sulfur isotope in rivers can help us to calculate the proportion of sulfate from different sources,meantime we can understand the relationship between river ecological environment and human activities.As the water resources of the Yangtze River tributary accounts for 65% of the surface water resources in Guizhou province.The Yangtze River tributary area accounts for the Guizhou province's land area of 66%.Wujiang River of the Yangtze River tributary is the first river in Guizhou Province followed by Qingshui River.Chishui River of the Yangtze River tributary has a good ecological and economic significance.Sancha River of the Yangtze River tributary is affected by human activities more than the others.Meanwhile the strata of four watersheds are complete.Therefore,Wujiang River,Chishui River,Qingshui River and Sancha River of the Yangtze River tributary was selected as the object of this study.Utilizing the water chemistry characteristics of rivers and sulfur isotopic composition analyze the source of sulfate in the river and then calculate the contribution of different sources to reflect the impact of nature and human activities on Yangtze River tributary.And then reflect the tributary of the Yangtze River on the global environmental changes in a certain period of time.In this article,using the sulfur isotopes of four rivers in the dry and rainy season analyzes and discusses its characteristics then concludes the following conclusions:(1)These tributaries of the Yangtze River are generally weakly alkaline inGuizhou area(pH=8.05).The sulfate content of the river(SO42-=0.595mmol/L)is higher than the world's bigger rivers,the Yangtze River and the Jialing River,however it is lower than the Yellow River.The sulfate content of the river have strong regional differentiation characteristics.(2)Comparing with other large rivers in China,the ?34S value(?34S=-1.09‰)of the Yangtze River tributary is higher than the tributary of the Lake Hongfeng while is lower than that of the Jialing River,the Yellow River,the annual surface water of Beijing,the Urumqi river,the Yangtze River and the Wuyang River.Their frequency range are basically distributed between the Mackenzie river and the Amazon river.(3)The sulfate of Yangtze River tributary has 31% from sulfide oxidation,29%from atmospheric precipitation,20% from coal,17% from human activities and 3%from evaporate dissolved.(4)Sulfate is mainly derived from the oxidation of sulfide,followed by input of atmospheric precipitation and then there is human activity and coal input while individual rivers has the dissolution of evaporation in the Yangtze River tributary in Guizhou area.Volatile rock,coal,pyrite and other sulfur-containing minerals,human activities,the degree of sulfate inputting,acid content of atmospheric precipitation,other inputting of soil sulfate and other are closely related to the proportion of different sources.