Spatial variation of metals and acid volatile sulfide in floodplain lake sediment

• Published in: Environmental toxicology and chemistry 2003-03, Vol.22 (3), p.457-465
• Main Authors: van Griethuysena, Corine, Meijboom, Erwin W., Koelmans, Albert A.
• Format: Article
• Language: English
• Subjects: Acid volatile sulfide; Acids - chemistry; Analysis of Variance; Applied sciences; avs; bioavailability; bodemchemie; cadmium; Chemical Precipitation; contaminated sediments; diffusion method; Exact sciences and technology; Floodplain sediment; floodplains; Fresh Water - chemistry; fresh-water sediments; Freshwater; gelderland; Geologic Sediments - chemistry; Geostatistics; geostatistiek; heavy metals; lakes; meren; Metals, Heavy - chemistry; nederland; Netherlands; Oxidation-Reduction; Pollution; Pollution sources. Measurement results; ruimtelijke variatie; sediment; simultaneously extracted metals; Soil and sediments pollution; soil chemistry; spatial variation; stroomvlakten; Sulfides - chemistry; sulfur; toxicity; Trace metals; Volatilization; water bottoms; Water Pollutants, Chemical; Water Pollution; waterbodems; Waterverontreiniging; zware metalen; zwavel
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.5620220301

In risk assessment of aquatic sediments, much attention is paid to the immobilizing effect of acid volatile sulfide (AVS) on trace metals. The difference of AVS and simultaneously extracted metals (SEM) gives an indication of metal availability. In floodplain sediments, where changing redox conditions occur. AVS may play a major role in determining variation in metal availability. The importance of spatial heterogeneity has been recognized in risk assessment of trace‐metal‐polluted sediments. However, little is known about spatial variation of available metal fractions. We studied spatial variability of sediment, environmental conditions, total contaminant concentrations, and available metals (as SEM‐AVS or SEM‐AVS/fOC) in a floodplain lake. The top 5 cm of sediment was sampled at 43 locations. Data were analyzed with correlation and principal component analysis as well as with geostatistical methods. Trace metal and SEM concentrations and most sediment characteristics were more or less constant within 10%. In contrast, AVS concentrations were much more variable and showed a strong spatial dependence due to differences in lake depth, total sulfur pools, and redox potential (Eh), which resulted in crucial differences in trace‐metal availability within the lake. The spatial pattern of SEM‐AVS deviates from total or normalized trace‐metal patterns. This particularly has implications for risk assessment of sediments prone to dynamic hydrological conditions, where AVS concentrations are also variable in time.