An assessment of heavy metal contamination sources in sediments from Hongfeng Lake
红枫湖沉积物中重金属元素溯源分析的初步探讨

Abstract: Concentrations of heavy metals and organic matter in sediments from Hongfeng Lake were determined and the average enrichment factors (AEFs) were used to evaluate the degree of heavy metals accumulation. The results showed that heavy metals contamination in the lake could be divided into three groups: negligible to low contamination (AEFs < 2), which is the case of Cd, Pb, Zn, Cr, As, Fe and Mn; moderate contamination (AEF = 2-3), which is the case of Cu; certain to severe contamination (AEFs > 3), which is the case of Ni and Hg. Principal component analysis (PCA) was also applied to estimate the sources of heavy metals contamination. Prior to the statistical analysis, Al was used to normalize the concentrations of heavy metals, which eliminates the effect of granularity of the sediments on the distribution of heavy metals. Its results demonstrated that the principal components from the first to the three accounted for 48.7%, 20.5%, 12.6% of the total variance, respectively, implicating that discharge of industrial wastewater and effect of Fe and Mn, organic matter, erosion of rocks (background value) were possible sources of this contamination. In addition, hierarchical cluster analysis (HCA) indicated that the 14 stations could be divided into four groups according to the pollution degree. The results from this analysis reflect that pollution of some heavy metals is relatively heavy in sediments from Hongfeng Lake and that industrial discharge should be the main source of that contamination.