Study On Variation Regularity Of Rare Earth In Five Water Systems Of Beijing

Understanding the content,distribution,and sources of rare earth elements(REEs)in regional water bodies is crucial for effective water resource management,water quality assessment,and ecological environment development.A study was conducted to examine the rare earth content in the five major water systems in Beijing:Yongding River,Chaobai River,Beiyun River,Jiyun River,and Daqing River.The study aimed to explore the variation patterns of rare earth content and compare it with the content found in the water bodies of the Baotou section of the Yellow River,revealing the geographical zoning pattern of rare earths in China.The main findings are as follows:The content of each rare earth element in the water bodies of Yongding River,Chaobai River,Beiyun River,Jiyun River,and Daqing River was measured,and the variation patterns of rare earth content in different rivers were studied.Using N,N,N’,N’-tetraoctyl-3-oxapentanediamide(TODGA)as an extractant,the samples were extracted and analyzed using X-ray fluorescence spectroscopy.The Beiyun River had the highest total REEs concentration,ranging from 35.95 to 59.78 μg/mL.The light rare earth elements were dominant,with a total concentration of 23.50μg/mL for La to Nd,while the heavy rare earth elements had a total concentration of 2.89 μg/mL for Sm to Lu.These results indicate that the Beiyun River has high light rare earth elements to heavy rare earth elements ratio of 7.90.The study revealed significant differences in the concentration and distribution patterns of rare earth elements compared to the Baotou section of the Yellow River.Industrial emissions from Baotou City significantly affected the rare earth element concentration in the Yellow River,leading to an increase in the proportion of light rare earth elements.In contrast,the concentration of rare earth elements in the Beijing water system was lower,with the Daqing River having a concentration ranging from 15.79 μg/mL to 17.48 μg/mL.The study unveiled a distinct geographical zoning of REEs distribution,with higher abundances of light rare earth elements(LREEs)in northern China and a more widespread presence of heavy rare earth elements(HREEs)in the southern region.In river systems,the sequence distribution of REEs is Ce>La>Nd>Pr>Sm>Gd>Dy>Er>Yb>Eu>Lu>Ho>Tb>Tm,while in lakes,it is Ce>La>Nd>Pr>Sm>Gd>Dy>Er>Yb>Eu>Ho>Tb>Tm>Lu.