Fig. 4. (A) The effect of equilibration time on sediment arsenic partitioning. Comparison is made between initial sediment partitioning and partitioning in sediment shaken for 24 h. (B) Iron concentrations of selected fractions before and after resuspension. Initial partitioning was determined using the average of results from three soil samples, partitioning in resuspended sediment is from the average of two. The error bars represent the standard deviation.