摘要
The sedimentation of metals can preserve the historical record of contaminant input from local and regional sources and provide information on the historical changes in regionalwater and sediment quality. We report the 210Pb activities and the heavy metal （Cd, Cr, Cu, Mn, Pb and Zn）depth profiles from sediment cores retrieved in 2010. The mean sedimentation rates of 0.85-1.5 cm/yr aredetermined by 210 Pbdating. The sediments in the tidal flat have recorded heavy metaldeposition and thus allow the establishment of a connection between the temporal evolution of the heavy metal pollution and the historical changes in the economicdevelopment of Lianyungang. The enrichment factors （EF） are calculated to estimate the level of contamination stored in these sediments. The results show that in the studied sites, Cr and Cudisplay low EF values and are mainly from lithogenic origin. For the other studied trace metals, a great variability in the sedimentary record is observed. Significant anthropogenic enrichment over the last 50 years is revealed at the tidal flat that receives fluvial inputs. Zinc is the elementwith the highest EF values, followed by the order of Pb 〉 Cd 〉 Mn 〉 Cu and Cr. The temporal variations of the heavy metals peakduring the late 1980s to the early2000s and show adecreasing trend afterward. The pollution intensity of the tidal flat isdetermined by using EF and thegeo-accumulation index （Igeo ）,which show that, based on the Igeo scale, the tidal flat of Haizhou Bay is unpolluted to moderately polluted.
The sedimentation of metals can preserve the historical record of contaminant input from local and regional sources and provide information on the historical changes in regionalwater and sediment quality. We report the 210Pb activities and the heavy metal （Cd, Cr, Cu, Mn, Pb and Zn）depth profiles from sediment cores retrieved in 2010. The mean sedimentation rates of 0.85-1.5 cm/yr aredetermined by 210 Pbdating. The sediments in the tidal flat have recorded heavy metaldeposition and thus allow the establishment of a connection between the temporal evolution of the heavy metal pollution and the historical changes in the economicdevelopment of Lianyungang. The enrichment factors （EF） are calculated to estimate the level of contamination stored in these sediments. The results show that in the studied sites, Cr and Cudisplay low EF values and are mainly from lithogenic origin. For the other studied trace metals, a great variability in the sedimentary record is observed. Significant anthropogenic enrichment over the last 50 years is revealed at the tidal flat that receives fluvial inputs. Zinc is the elementwith the highest EF values, followed by the order of Pb 〉 Cd 〉 Mn 〉 Cu and Cr. The temporal variations of the heavy metals peakduring the late 1980s to the early2000s and show adecreasing trend afterward. The pollution intensity of the tidal flat isdetermined by using EF and thegeo-accumulation index （Igeo ）,which show that, based on the Igeo scale, the tidal flat of Haizhou Bay is unpolluted to moderately polluted.
基金
supported by the Open Fund of State Key Laboratory of Pollution Control and Resources Reuse(No.PCRRF11024)
the Fostering Project of Major Research Plan of National Natural Sciences Foundation of China(No.91025022)
the Natural Science Foundation of Huaihai Institute of Technology(No.Z2011001)
the Priming Scientific Research Foundation for the Junior Teachersin Huaihai Institute of Technology(No.KQ09041)
the Project of Innovation from Undergraduate in Jiangsu Province(No.SY201311641107001)
the project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
