Chemistry of water and sediment from the benthic boundary layer at a site in the Northwest Atlantic Ocean

• Main Author: Schmidt, R.L.
• Language: unknown
• Published: 2011
• Subjects: 37 INORGANIC; ORGANIC; PHYSICAL AND ANALYTICAL CHEMISTRY; 54 ENVIRONMENTAL SCIENCES; SEAWATER; CHEMICAL PROPERTIES; SEDIMENTS; WATER CHEMISTRY; ALLOYS; ATLANTIC OCEAN; BACTERIA; BOUNDARY LAYERS; CALCITE; CALCIUM; CARBON; CHEMICAL COMPOSITION; CHEMICAL REACTION KINETICS; CHEMISTRY; CORROSION; DATA COMPILATION; GRAPHS; MAGNESIUM; MINERALOGY; ORGANIC COMPOUNDS; PARTICLE SIZE; PH VALUE; PRESSURE DEPENDENCE; REDOX POTENTIAL; SALINITY; SCALING; SEA BED; STANDARDS; STRONTIUM; SULFATES; SULFIDES; SUSPENSIONS; TABLES; TRACE AMOUNTS; ALKALINE EARTH METAL COMPOUNDS; ALKALINE EARTH METALS; CALCIUM CARBONATES; CALCIUM COMPOUNDS; CARBON COMPOUNDS; CARBONATES; CHALCOGENIDES; CHEMICAL REACTIONS; DATA; DATA FORMS; DISPERSIONS; ELEMENTS; Northwest Atlantic
• Online Access: http://www.osti.gov/servlets/purl/5794497; https://www.osti.gov/biblio/5794497; https://doi.org/10.2172/5794497

A primary objective of this study was to characterize the corrosive potential of the benthic boundary layer at a site where selected metal alloys were being exposed. Those properties of sea water and sediment likely to affect the corrosion of alloys that were measured in this study include salinity, pH, scale-forming cations, redox potential, dissolved gases, heavy metal ions, abrasive particulates, and microorganisms. The chemical properties of water from the benthic boundary layer do not appear to differ substantially from those of surface sea water. Salinity, pH and major ion content of this water appear to be representative of well-oxygenated, unpolluted oceanic water. On the basis of the properties examined, it is expected that corrosion of metals exposed in the deep sea would not differ greatly from that in surface waters having similar properties. However, the effect of pressure on corrosion rates and chemical forms of corrosion products may be an unknown factor of major importance. Increased calcite solubility at depth has been well-documented and the resulting inhibited formation of protective scale may be indicative of the effects of pressure on corrosion. The presence of sulfate-reducing bacteria in the bottom sediments at this site indicates that, if diffusion of O/sub 2/ into the sediment was inhibited, stainless steels buried in the mud would lose passivity and corrosion rates would increase. The eventual fate of corrosion products is dependent on their properties and the properties of their environment. In benthic boundary layer sea water it might be expected that corrosion products would be released as metal oxides. (JGB)