816 resultados para SEA-WATER


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A device and a specific procedure for simultaneous concentration of trace ele¬ments from sea water by co-precipitating them in precipitate of magnesium hydroxide obtained by electrolytic alkalization of samples in a two-chamber electrolyzer are described. Analyses of sea water samples for zinc, iron, copper, nickel and lead demonstrate that the method produces a thousand-fold concentration and gives results that agree well with those obtained by extractive concentration using diethyldithiocarbamate and 8-hydroxyquinoline in chloroform. Extracts were analyzed by flame atomic absorption. Correlation coefficients of results obtained with use of these two methods of concentration were 0.76-0.87 for zinc, iron, and copper at confidence levels of 0.05-0.07. Average zinc and iron concentrations determined by the method differed by less than 10%.

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Surface and upper-layer pollution of seas and oceans by crude oil and refinery products is under study by investigators in many countries. The Intergovernmental Oceanographic Commission (IOC) and World Meteorological Organization (WMO) have prepared an international experimental project that is to be carried out within the framework of the Integrated Global Oceanic Station System (IGOSS). The purpose of the project is to prepare a picture of distribution and dynamics of oil pollution. Parameters to be observed include: oil patches (slicks), floating lumps of tar on the surface, and hydrocarbons emulsified and dissolved in water. Cruise 22 of R/V Akademik Kurchatov took the ship through regions being the most suitable for pollution studies. They were conducted from March through June 1976. On the cruise, oil slicks were observed visually by a procedure recommended by the international program. Areas of the slicks were determined from speed of the ship and time required to cross them. Surface samples were taken along the path of the ship for determination of concentrations of dissolved and emulsified hydrocarbons in water. In addition, samples were taken from deep water by a 7-liter vinyl water bottle at 17 stations. Hydrocarbons present in the samples were extracted immediately with carbon tetrachloride. Final determination of hydrocarbons was made by infrared spectrophotometry. This method is currently accepted in the Soviet Union in an arbitration capacity for determination of petroleum products dissolved and emulsified in sea water. Infrared spectrophotometry is used to determine hydrocarbons containing methyl and methylene groups, but they are not identified as to origin.

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ATP distribution in coastal waters off Peru was examined and was found to differ with hydrological conditions in this area; maximal values in the vicinity of an intense upwelling were the same in 1974 and 1978. ATP distribution was highly non-uniform in 1978, particularly in upper layers of the northern section, due to disruption of a community (dense patches of bloom), which began about 10-15 days before our observations, and also because of appearance of a red tide. Unusually intense microplankton metabolism was found in Peruvian waters, particularly in the lower layers of the northern section, where ATP concentration of 3.6 ?g/l were found. Values of live microplankton biomass presented.