Changes in Cd and Zn bioavailability upon an experimental resuspension of highly contaminated coastal sediments from a tropical estuary

摘要: Bioavailability evaluations can be an important tool to determine the quality of dredging sediments. Sequential extractions are commonly used assess different chemical forms trace metals in coastal sediments; however, sometimes they expensive and time-consuming. Additionally, these analyses do not represent possible changes due resuspension during after activity. Newer, easier options evaluate bioavailability necessary understand preview resulting from disposal areas. This study aims Cd Zn sediment a highly contaminated area Sepetiba Bay, Brazil. Twelve surface samples this location were submitted experiment two time intervals (1 24 h). The extraction potentially bioavailable (1 mol L−1 HCl-extractable) fractions strongly bound (concentrated HNO3-extractable) sequentially carried out. More than 50 % concentrations fractions. change indexes proposed; estimated as relative percentage resuspension. However, stations presented increases HCl-extractable above effects range low medium National Oceanic Atmospheric Administration which same limits adopted for Brazilian environmental jurisdiction. Positive correlation with TOC evidenced importance organic matter binding preserve fraction. Fe Mn partitioning was major geochemical control on upon short-time periods.