Nutrients and Heavy Metal Concentration and its Ecological Risk Assessment in The Sediments of Yueya River in Tianjin
In order to master the environmental risk level of regional sediments and provide technical basis for environmental risk management,Yueya River in Jinnan District was taken as the research object.A total of 22 surface and under layer sediment samples were collected and their contents of organic matter,total nitrogen,total phosphorus,arsenic,copper,nickel,mercury,lead,cadmium,chromium,zinc and other indicators were determined.The single factor pollution index,Nemerow pollution index,ecological risk index and organic pollution index were used to analyze the risk levels of nutrients and heavy metals.The results showed that the spatial difference of each index was obvious.Single factor evaluation results showed that the surface samples were zinc>total phosphorus>total nitrogen = copper = nickel = lead = cadmium = lead>arsenic.In the lower samples,all the indexes were clean except that the total phosphorus and zinc reached the slightly polluted level.Nemerow's comprehensive evaluation results showed that the pollution levels of each index in the surface samples were different,total nitrogen = total phosphorus = copper = nickel = cadmium = zinc>chromium>arsenic = lead.The RI of each index belonged to low risk,but the surface sample had significant spatial difference,while the bottom sample had little difference.The organic pollution index was much lower than the evaluation standard 0.5％,belonging to the"clean"level.
NETL
NSTL
万方数据
