闽江福州段河岸带土壤重金属空间分布特征与污染风险评价OA

In this study,we investigated the concentrations and spatial distributions of six heavy metals(Cd,Cr,Cu,Ni,Pb,and Zn)in surface soils of the riparian zone of the Fuzhou section of Minjiang River.Single-factor analysis of variance(ANOVA)was applied to compare regional variations in soil heavy met-al content,multiple pollution indices were used to evaluate ecological risks,and principal component anal-ysis(PCA)combined with the absolute principal component score-multiple linear regression(APCS-MLR)model was employed to identify and quantify potential sources of heavy metal contamination.We aimed to elucidate the status of heavy metal pollution in riparian soils and provide scientific guidance for pollution prevention and mitigation in this ecologically sensitive area.Between May and June 2023,a total of 240 surface soil samples were collected from 12 sampling sites of the study area for determination of heavy metals.The sites were distributed across three river segments:M1-M6 in the Minhou reach,B7-B8 in the Beigang reach,and N9-N12 in the Nangang reach.At each site,four parallel sampling transects were established,with five sampling points spaced at 2 m,5 m,10 m,20 m,and 40 m from the water along each transect.Results show that:(1)The average concentrations of heavy metals in the riparian zone soils were as follows:Cd(0.36 mg/kg),Cr(57.85 mg/kg),Cu(27.32 mg/kg),Ni(25.65 mg/kg),Pb(60.76 mg/kg),and Zn(128.20 mg/kg).Notably,the average Pb content was below the soil background value of Fuzhou City,while the average concentrations of the other five heavy metals were 1.05 to 1.5 times those of the background value.(2)The soil content of Ni in the Beigang reach was significantly higher than that in the Minhou reach and Pb high than that in Nangang reach(P＜0.05),and the contents of Cu,Ni,and Pb in near-water soils were significantly higher than in soils farthest from the water(P＜0.05).(3)Both single-factor pollution assessment and Nemerow comprehensive pollution assessment indicate mild pollution by Cd,Cr,Cu,Ni,and Zn,and no Pb pollution.Single factor risk analysis shows that Cr,Cu,Ni,Pb,and Zn posed a slight potential risk,and Cd posed a moderate risk.The comprehensive potential risk of the six heavy metals was low.(4)The sources of heavy metals in the riparian soils of the study area ranked as follows:natural sources(36.08％)＞agriculture(24.55％)＞motor vehicles(15.72％)＞unidenti-fied(13.05％)＞industry(10.60％).Specifically,sources of Cu,Ni,and Pb were primarily natural,while Cd was mostly from agriculture,Zn mostly from motor vehicles,and Cr mostly from industry.These results provide a scientific basis for preventing and controlling heavy metal pollution of Minjiang River and its ri-parian soils