Grain-Scale characterization of metals in New York/New Jersey harbor sediment

Characterization of metals in sediments from the New York/New Jersey Harbor is necessary as part of the basic information needed in work related to dredging and environmental effects and restoration efforts in the region. In response to this need, the National Institute of Standards and Technology (NIST) created Standard Reference Material (SRM 1944, New York/New Jersey Waterway Sediment). This reference material gives values for selected metals and chemical compounds on a bulk scale. In this experiment, analyses were made on grains from the SRM and on a smaller -sized grain fraction from the original material used in preparing the SRM that was not included in the SRM. We used scanning electron microscope/back-scattered electron detector (SEM/BSE), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD) and synchrotron computed microtomography (CMT) techniques to obtain metal concentration data on individual grains in these materials.