Trace metal

About: Trace metal is a research topic. Over the lifetime, 5125 publications have been published within this topic receiving 181046 citations.

Assessment of Zn, Cu, Pb and Ni contamination in wetland soils and plants in the Lake Victoria basin

Abstract: The impact of waste disposal on trace metal contamination was investigated in eleven wetlands in the Lake Victoria Basin. Samples of soil, water and plants were analysed for total Zn, Cu, Pb and Ni concentrations using flame atomic absorption spectrophotometry. The trace metal concentrations in soil were the highest in Katanga wetland with the highest mean concentrations of 387.5±86.5 mg/kg Zn, 171.5±36.2 mg/kg Pb, 51.20±6.69 mg/kg Cu and 21.33±2.23 mg/kg Ni compared to the lowest levels observed at Butabika (30.7±3.2 mg/kg Zn, 15.3±1.7 mg/kg Pb, 12.77±1.35 mg/kg Cu and 6.97±1.49 mg/kg Ni). Katanga receives waste from multiple industrial sources including a major referral city hospital while Butabika is a former solid waste dumpsite. Wetland soil near a copper smelter had a Cu concentration of 5936.3±56.2 mg/kg. Trace metal concentrations in industrial effluents were above international limits for irrigation water with the highest concentrations of 357,000 µg/L Cu and 1480 µg/L Zn at a Cu smelter and 5600 µg/L Pb at a battery assembling facility compared to the lowest of 50 µg/L Cu and 50 µg/L Zn in water discharged from Wakaliga dumpsite. Uptake of trace metals from soil differed from plant to plant and site to site. Higher levels of trace metals accumulated in the root rather than in the rhizome and the least amount was in the leaf. The study identifies industry as a potential source of trace metal contamination of water and the environment pent-up need for policy intervention in industrial waste management .

Macronutrient and trace-metal geochemistry of an in situ iron-induced Southern Ocean bloom

Abstract: We have investigated the effect of iron supply and increased phytoplankton growth on the cycling of the macronutrients phosphate, nitrate and silicic acid as well as the micronutrients copper (Cu), nickel (Ni), zinc (Zn) and cadmium (Cd). Nutrient levels were measured in situ in an iron-induced phytoplankton bloom at 61°S 140°E in the Southern Ocean Iron Release experiment (SOIREE). Nutrient ratios upon arrival at the study site indicate that much of the seasonal phytoplankton productivity was by iron-limited diatoms growing at low mean light levels. The addition of iron (Fe) induced a bloom that led to a draw-down in the macronutrients in ratios consistent with the growth of diatoms under iron-replete conditions. None of the bioutilised trace metals Cu, Ni, Zn or Cd showed any indication of co-limitation, with Fe, of phytoplankton growth. Zn concentrations did not decrease by algal uptake as expected. Cd was partitioned to the particulate phase indicating consumption by the algae. Cd was preferentially utilised with respect to P with a α Cd/P =5.8. Interpretation of the Cd/Ca data from the sedimentary record using this higher induced α Cd/P value would imply even higher Southern Ocean surface water P during the last glacial maximum.