Determination of geochemical baseline and pollution of soil heavy metals in Suzhou, China

摘要

To investigate the enrichment of soil heavy metals, 50 soil samples were collected and the vanadium (V), chromium(Cr), zinc (Zn), lead (Pb), copper (Cu) and arsenic (As) contents were measured by using an X-ray fluorescencespectrometer. The environmental geochemical baseline values of heavy metals were determined by usingstandardised methods, and the pollution and enrichment degrees of heavy metals were evaluated based on thegeoaccumulation index method and enrichment factor method. The results show that the vanadium, chromium,copper, zinc, lead and arsenic contents vary widely, with mean values of 81.32, 65.54, 17.16, 49.28, 20.04 and11.68 mg/kg, respectively. Except for arsenic, the average values of the other five elements are lower than the soilbackground values of Anhui Province. The results of the standard reference method indicate that the six heavymetal elements have a strong correlation with iron (Fe), and the baseline values of heavy metals are 81.33, 65.56,17.18, 49.29, 20.04 and 11.67 mg/kg, respectively. The mean values of I_(geo) for the six heavy metals are less than 0,indicating that there is no pollution of heavy metals in the soil of Suzhou. The average enrichment factor is greaterthan 1, with slight enrichment, and the interference of human activities on soil heavy metals is not obvious.