Phosphate rock (PR) and phosphoric acid (PA) are an effective combination of P sources for immobilizing Pb in contaminated soils. This column experiment examined the effectiveness of different application methods on Pb immobilization in a contaminated soil. Phosphate was applied at a P/Pb molar ratio of 4 with half as PR and half PA. While PR was mixed with the soil or placed as a layer, aqueou...

Aims The aim of the present study was to compare lead accumulation and tolerance among heavy metal hyperaccumulating and non-hyperaccumulating metallophytes. Methods To this purpose, we compared Pb tolerance and accumulation in hydroponics among calamine and non-calamine populations of Silene vulgaris, Noccaea caerulescens, and Matthiola flavida. We established the effects of Ca on Pb tolerance...

We examined the anthropogenic lead (Pb) burden that accumulated in sediment of lakes in the southeastern USA during the last *150 years. Mining, smelting, agriculture, and fossil-fuel combustion are known to have contributed to Pb pollution in lakes of other regions. Few studies, however, have examined Pb sequestered in lakes of the southeastern USA, particulary peninsular Florida, which is sub...

Two cores collected in 2001 and 2004 from Flanders Moss ombrotrophic peat bog in central Scotland were dated (14C, 210Pb) and analysed (ICP-OES, ICP-MS) to derive and compare the historical atmospheric deposition records of Sb and Pb over the past 2500 years. After correction, via Sc, for contributions from soil dust, depositional fluxes of Sb and Pb peaked from ca. 1920-1960 A.D., with >95% of...

Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to ~3500-3200 cal.yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We ha...

Lead contamination is of great concern because of its adverse effects on human health, especially children. This research evaluated the effects of phosphate rock on chemical associations of Pb in eight Pb-contaminated soils using a sequential extraction procedure. The chemical fractions are operationally defined by an extraction sequence in the order of increasing ability to dissolve Pb of lowe...

Using molecular dynamics simulation, the effect of Pb surfactant for the thin film growth of Co atoms on Cu 111 substrate was investigated. Specifically, the behavior of Co atoms being deposited on Cu 111 substrate with predeposited Pb layer was extensively investigated and compared with the case of without Pb layer to explain the effect of Pb surfactant. It was observed that Pb layer was float...

Pb inhibits plant growth. To study Pb tolerance in rice (Oryza sativa), we screened 229 varieties for Pb tolerance or sensitivity. Three-day-old seedlings were treated for 12 d with 20 microM Pb solution. Based on the dry weight of the root, three Pb-tolerant (var CH-55, var KH-2J, var Kumnung) and three Pb-sensitive (var Aixueru, var C-9491, var Milyang23) rice varieties were selected. The roo...

A spectroscopic investigation of the complexes formed between the Pb(II) ion and D-penicillamine (H2Pen), a chelating agent used in the treatment of lead poisoning, was carried out on two sets of alkaline aqueous solutions with CPb(II) ≈ 10 and 100 mM, varying the H2Pen/Pb(II) molar ratio (2.0, 3.0, 4.0, 10.0). Ultraviolet-visible (UV-vis) spectra of the 10 mM Pb(II) solutions consistently show...

Neodymium model ages for fine-grained formations of the Paleoproterozoic Huronian Supergroup (McKim, Pecors, Gowganda, Gordon Lake) range from 3.00 to 2.55 Ga and indicate a provenance dominated by the Late Archean Superior Province to the north and west. The stratigraphically highest unit (Gordon Lake Formation) has a distinctive Nd-isotopic composition, with TDM being 100-400 Ma younger than ...