Study On Pollution Characteristics And Potential Ecological Risk Of Heavy Metals In Urban Surface Water Sediments In Yongkang City

Urban surface sediment of surface water as to constitute an important part of the urban environment,sediment is an important part of the water,heavy metal pollution of water has double function of the library and the source of secondary pollution accumulation,plays an important role in the research of water heavy metal pollution.Therefore,it is significant to study the degree of heavy metal pollution in the surface sediments,which is important to understand the risk of heavy metals in the water environment,Yongkang,as the “hardware city” of china,the hardware technology park is the largest professional hardware market in china,including mechanical hardware,decoration hardware and tools hardware etc.Therefore,it is important to study the heavy metal pollution of surface water in Yongkang city.In order to understand the pollution characteristics of heavy metals in surface water sediments of Yongkang,we analyzed the concentrations of 10 heavy metals including Ti,Cr,Mn,Co,Ni,Cu,Zn,As,Pb and Fe in 122 sediment samples,explored the underlying source of heavy metals and then assessed the potential ecological risks of those metals by methods of the index of geo-accumulation and the potential ecological risk.The study results showed that:(1)10 heavy metal contents followed the order: Fe > Ti > Mn> Zn > Cr > Cu > Pb > Ni > As > Co,all heavy metals except for Ti were 1.17 to 3.78 times higher than those of Zhejiang Jinhua-Quzhou basin natural soils background values;The concentrations of all heavy metals had a significantly correlation between each other,indicating that those heavy metals had similar sources of pollution,and it mainly came from industrial and vehicle pollutions;(2)Analyzed the single factor level of surface water sediments of Yongkang by using single factor pollution,the results shows that average single factor of of 10 heavy metal followed the order: Cr >Ni >Zn >Cu >Fe >As >Mn >Ti >Co.All heavy metals except for Cr、Ni、Cu and Zn were low pollution,indicating that the area should pay close attention to Cr、Ni、Cu and Zn.The contamination level of heavy metals in Yongkang was slight in total,but was heavy in local areas.(3)89.34% of the potential ecological risk indexes(RI)were low and 10.66% were higher.The potential ecological risk of 9 heavy metals in sediments were in the following order: Cu > As > Ni > Cr > Pb > Co > Zn > Mn > Ti,Cu and As contributed the most to the total potential ecological risk,accounting for 22.84% and 21.62%,others had a total of 55.54%.(4)Pollution extent of heavy metals in sediments was evaluated on the basis of the index of geoaccumulation,pollution degree of heavy metal followed the order: Cr >Zn >Ni>Cu >Fe >As >Pb >Mn>Ti,thereinto,Cr,Zn,Cu and Ni were moderately polluted or heavily polluted at some sampling sites.Based on the above analysis,with Zhejiang Province,“a total of five water” treatment efforts to increase,water pollution is no longer the most serious pollution of surface water in Yongkang City,and residual heavy metal elements in the surface sediments is a potential risk,this study can be drawn,Yongkang City,surface water heavy metal pollution in the sediments is slight,the local pollution serious.