For the purpose of nondestructive measurements hazardous heavy-element-containing substances in soil samples, emerging technique, triple-exposure X-ray computed tomography (CT), is proposed. The use triple exposure (i.e. three different acceleration voltages for tube) improves accuracy identification atomic number a heavy element. With lead as target element, virtual microtomography simulations...

The Lemoine tailings of Chibougamau, Quebec, Canada, were deposited as a pH-neutral mineral conglomerate consisting of aluminum-silicates, iron-aluminum-silicates, pyrite, chalcopyrite, and sphalerite. These tailings are colonized by an active population of Thiobacillus ferrooxidans which is localized to an acid zone occupying 40% of the tailings' surface. This population peaked at 7 x 10 most ...

Processing of by-product heavy minerals (amang) from tin mining involves potential exposure to external and internal sources of radioactivity. The radioactivity arises through the presence of thorium and uranium series radionuclides in the various minerals. Monazite is the most radioactive mineral, containing 3% to 7% thorium by weight, while ilmenite is generally the least radioactive mineral ...

The Xihuashan granitic complex (southern China) is mainly composed of coarse-grained porphyritic biotite granite (G–a), medium-grained porphyritic biotite granite (G–b), and mediumto fine-grained porphyritic biotite granite (G–c). The G–a granite is characterized by monazite-(Ce) and xenotime-(Y), in addition to commonly observed zircon and uranoan thorite. In the G–b and G–c intrusive units, m...

The aqueous concentrations of heavy metals in soils, sediments, and aquatic environments frequently are controlled by the dissolution and precipitation of discrete mineral phases. Contaminant uptake by organisms as well as contaminant transport in natural systems typically occurs through the solution phase. Thus, the thermodynamic solubility of contaminant-containing minerals in these environme...

Co-contamination of the environment with toxic chlorinated organic and heavy metal pollutants is one of the major problems facing industrialized nations today. Heavy metals may inhibit biodegradation of chlorinated organics by interacting with enzymes directly involved in biodegradation or those involved in general metabolism. Predictions of metal toxicity effects on organic pollutant biodegrad...

Loveringite-davidite members of the crichtonite group were synthesized at high pressure and temperature (7.5 kbar, 1000-1050 ~ from a melt of TiO2 and rare earth element (REE) enriched basaltic andesite composition. Four sets of partition coefficients for La, Sin, Ho, Lu and Sr (analogue for Eu 2+) were obtained. These show that light and heavy REE are readily accommodated, but the intermediate...

Tire dust is a significant pollutant, especially as a source of zinc in the urban environment. This study characterizes the morphology and chemical composition of heavy metal particles embedded in tire dust and traffic-related materials (brake dust, yellow paint, and tire tread) as measured by a field emission scanning electron microscope equipped with an energy dispersive X-ray spectrometer (F...

The alunite supergroup consists of more than 50 representative minerals with the general formula A B 3 (XO 4) 2 (OH) 6 , where A may be occupied by Na, is the trivalent cation , Al 3+ or Fe 3+ , but also Cu 2+ or Zn 2+ and X is the tetrahedral anion, S, P or As [1, 2]. The minerals of this supergroup form numerous complex solid solutions which crystallize in a rhombohedral system, space group R...