Evaluation Of Heavy Metal Pollution In Water And Sediment Of The Red River Mainstream(Yuanjiang Section)

There are many environmental problems in the Red River Basin,such as soil erosion,heavy metal pollution in water and so on.These problems have been widely concerned by the downstream countries.In this study,the spatial distribution of heavy metals in the main strean of Yuanjiang River and its tributaries and sediments was revealed by the study of the contents of heavy metals in the water bodies and sediments of the mainstream(Yuanjiang section)of the Red River basin.The basic situation of heavy metals in water bodies and sediments To evaluate.The main conclusions are as follows:(1)Yuanjiang River in the water in addition to As,the other heavy metals fluctuations in the larger.The content of Cu,Cr,Cd and Pb in the upper reaches of the Xila River in the upper reaches of the Small River,The content of heavy metal in the estuary and the dam is significantly lower than that in the dam.To a certain extent,the Red River(Yuanjiang section)downstream of the Nansha River,Ma plugging the power station of heavy metal interception.The tributaries of Lvzhi River,Kunlong River and the Paisha River have a great influence on the content of heavy metals in the main stream.(2)Yuanjiang main stream of sediment,in addition to As,the other heavy metal content fluctuations.The contents of Cu,Cd,Hg and Cr in the Dangshan River were significantly increased after the flooding of the Yuanjiang River,indicating that the mining of the Dahongshan copper mine had an important effect on the enrichment of heavy metals in the Yuanjiang main stream.Since then,the heavy metals in the middle reaches of the river have shown varying degrees of volatility,to the downstream river estuary exit in addition to Hg and Cr,the other significant increase in the content of heavy metals.(3)In addition to Hg and As,the contents of Cu,Cd,Pb and Cr in the main body of the Yuanjiang River were positively correlated with each other.But there was a significant negative correlation between the contents of Hg and As in the sediments.There was a significant correlation between the contents of Cu,Cd,Pb and As in the sediment,and there was a significant positive correlation between Cd,Hg and Cr,Hg and As content were significantly negatively correlated.The content of Hg and As in the water body is negatively correlated with the contents of Hg and As in the sediments,and the Hg and As in the sediments of Yuanjiang main stream will cause the second pollution of the water body to a certain extent.There is a significant positive correlation between the content of Cd in the main stream of Yuanjiang and the sampling point,and there is a tendency to accumulate with the increase of distance.The distance of Cu,Cd,Pb and As in the sediment of Yuanjiang main stream is Significant positive correlation relationships also show a tendency to accumulate with distance increases.(4)Based on the results of heavy metal pollution evaluation of water body and sediment,the water quality of Yuanjiang is better,and the water quality of the upper reaches of the main stream(Sanjiangkou-Mosha)is better than that of the middle and lower reaches(Mosha-estuary).The water quality of the tributaries is generally better than that of the mainstream Water quality.The results showed that the six kinds of heavy metals in the Yuanjiang River and the tributary sediment were Cd>Hg>Cu>Cr>As>Pb according to the pollution degree,and the potential ecological risk index method indicated that the flooding from the tributary Menglong River And the comprehensive ecological risk index of heavy metals is of moderate hazard.The ecological risk of six heavy metals is Cd>Hg>Cu>As>Pb>Cr,and the two evaluation methods are consistent.Sex,both show Cd and Hg as the main risk element,estuary sediment in a more serious state of pollution.