Showing papers on "Trace metal published in 1968"

Trace Metal Accumulation by Estuarine Mollusks

Abstract: In view of the relative paucity of information on trace metal distribution in marine animals, a series of studies were Initiated in order to investigate the mechanics of concentration of these materials. Data were obtained on a number of mollusk species. There is a wide variation in species ability to take up and concentrate zinc, lead, nickel, cobalt, iron, manganese, copper, cadmium, and chromium within their natural (estuarine) environment. Uptake rates in a controlled, simulated-environment system using various concentrations of lead, copper, cadmium, and zinc indicate that all of the species studied varied in their selectivity for the particular metal taken up. The rate of uptake, and the tissue level attained, were found to vary with time, and the particular metal concentration used. Using various lead concentrations it was observed that of the various anatomical areas, the muscle, mantle edge, mantle, remainder, gill, gonad, and digestive gland accumulated increasing tissue levels in the order given. Depletion is a relatively slow process in most cases; it varies from species to species as to rate and final tissue concentration.

Soil and grass filtration of domestic sewage effluent for the removal of trace elements.

Abstract: Soil and grass filtration of a domestic sewage effluent for trace element removal was investigated by applying oxidation-pondtreated waste water to twelve 2.44-meter-long, 30.5-cm-diameter, lysimeter columns and to a half-acre plot planted to common bermudagrass. Bermudagrass was also planted on the soil columns to aid in the removal of accumulated metals, thus prolonging the filtering capacity of the soil system. Four irrigation patterns, continuous flooding, alternate day flooding, one day wet-three days dry cycles and two days wet-five days dry cycles, were employed during the eleven week lysimeter test. Water samples were extracted from the soil columns at eight sampling depths to determine the soil depth at which the various trace metals were removed from the filtrate by the processes of adsorption, absorption and biological assimilation. Atomic absorption spectrophotometric techniques were used to determine the concentrations of iron, manganese, hexavalent chromium, nickel, copper, zinc, lead, cadmium, cobalt and strontium in the applied effluent, filtrate, soil and grass clippings. Filtrate samples for trace metal analysis were also extracted at shallow depths and from two groundwater zones at 9.1 and 15.2 meters depth under the grass plot. In the lysimeter study, iron, manganese, nickel, copper, zinc, lead and cadmium were removed from the filtrate at, or near, the soil surface. Some copper, zinc and cobalt were found in the deeper

Contamination problems in the trace analysis for protein bound metals

Abstract: From the results reported above it is evident that in most cases metal contamination, which is accidentally collected during the sampling of blood and the preparation of the serum, will be found in isolated protein fractions. The distribution of the trace metal contamination between protein and low molecular weight fractions appears to vary considerably from element to element. It will also depend on the total amount of the contaminant in relation to the size of the serum sample. Inspecting the metal elution peaks the conclusion might be reached that nearly symmetric peaks (Cu, Fe, Cr, Zn, Ga) indicate the formation of metal protein complexes. On the other hand, the distorted lanthanum peak suggests the presence of a different type of compound, possibly colloidal lanthanum hydroxide. Of the seven elements tested only manganese was not detected in the protein fraction. This is in agreement with the finding ofHoleysovska.4 This fact should simplify the determination of transmanganin.