Soil properties affecting metal extractability patterns in periurban calcareous agricultural soils in the mediterranean area

The potential risk of metal accumulation in periurban agricultural areas is a matter for concern. The climate characteristics and carbonate content of calcareous agricultural Mediterranean soils typical in these areas favour metal accumulation at the surface level; however there is also a risk of potential metal mobility. Our study focuses on the soil properties affecting metal mobility in these soils. Metal extractability patterns were assessed in soils after they were spiked with a mixture of Cd, Cu, Pb, and Zn and incubated up to 12 months, using one-step extraction methods [NaNO[3], a mixture of low molecular weight organic acids - LMWOA and diethylene triamine pentaacetic acid -DTPA-]. The concentration of extractable Cd was 50% lower in the soil with the highest carbonate content. LMWOA-extractable Cu was highest in soils with the lowest organic matter [OM] content at day 1 of the incubation experiment and in soils with the lowest carbonate and recalcitrant OM contents at 12 months. Fine mineral fractions determined the lowest DTPAextractable Cu. The highest Pb retention was in soils with the highest carbonate and clay contents. However, we were unable to establish any soil component affecting Pb extractability patterns. The Zn extractability pattern was related to particle-size distribution, which was highest in soils with a low proportion of fine mineral fractions. To summarise, carbonate, particle-size distribution and OM are relevant to potential metal mobility in these soils. The high DTPA-extractable metal values are evidence of a potential risk of metal mobility in the soils in the study

Procedimiento de colección y preservación de muestras de pelo humano para la determinación de metales / Procedure for collecting and preserving samples of human hair for the determination of metals

Se describe un procedimiento de colección y preservación de muestras de pelo humano para la determinación cuantitativa de metales. Su aplicación permite obtener entre 0,5 y 1,0 g de nuestra tomados de la región occipital (vértex posterior). En sy­u confección, se han tomado en consideración los procedimientos y recomendaciones elaborados por por la Agencia Internacional de la Energía Atómica y otras instituciones

Heavy metal pollution in drinking water and methods of removals

Water samples were collected from El-Abbasa Station of Drinking Water, Sharqia Governorate, before and after water treatments. The samples were examined for the presence of heavy metals using atomic absorption spectrophotometer. The effect of slaked lime and activated carbon on the removal of the present heavy metals was studied. The results obtained revealed the presence of cadmium, lead, mercury, copper and zinc in raw surface water [Ismailia Canal] before treatment with an average concentration of 20, 670, 850, 150, and 530 mug/L, respectively. The concentrations of cadmium, lead and mercury in raw surface water were above the permissible limit recommended by USEPA [1979]. After water treatment in El-Abbasa Station the concentrations of cadmium, lead, mercury, copper and zinc in purified drinking water was 10, 480, 540, 130, and 350 mug/L, respectively. Lead, mercury and copper were found in purified drinking water above the levels recommended by WHO [1971]. The reduction% of cadmium, lead, mercury, copper and zinc in raw surface water using slaked lime [300 ppm] was 100.00, 49.25, 48.23, 40.00, and 58.49, respectively, while using activated carbon filter in purified drinking water has a removal% of 100.00, 47.92, 90.74, 84.62, and 7.29, respectively. It can be concluded that slaked lime with alum treatment to raw surface water as well as activated carbon filtration of purified drinking water are effective processes in elimination of heavy metals from water