Heavy Metal

Abstract: Regional modeling of subsurface cadmium and zinc transport in a diffusely polluted area in the south of the Netherlands is the subject of this study. The atmospheric deposition of cadmium and zinc was caused by three zinc-ore smelters (point sources of emission). ...

Swelling mica exhibits unique characteristics for purification of drinking water contaminated by heavy metals and for selective removal of Sr2+ and Ba2+ ions from nuclear waste solution. As a new approach to recycle fly ash, conversion of fly ash to swelling mica has been attempted and ion-exchange properties of fly ash-derived swelling mica (referred to hereinafter as FA-swelling mica) were

Abstract: As a group, heavy metals include both those essential for normal biological functioning (e.g., Cu and Zn), and nonessential metals (e.g., Cd, Hg, and Pb). Both essential and nonessential metals can be present at concentrations that disturb normal biological functions, and which evoke cellular stress responses. The cellular targets for metal toxicity include tissues of the kidney, liver, heart, and the immune response and nervous systems. Intriguingly, manipulations of specific metals, their reservoirs, and the cellular stress response can have therapeutic effects on certain diseases. In this minireview, we will consider both the biological responses to stressful levels of heavy metal cations, and experimental and clinical manipulations of these cations as a means to improve human health parameters.

In this work, a brewer’s yeast strain was used to remove heavy metals from a synthetic effluent. The solid–liquid separation process was carried out using the flocculation ability of the strain. The yeast strain was able to sediment in the presence of Cu2+, Ni2+, Zn2+, Cd2+ and Cr3+, which evidences that the flocculation can be used as a cheap and natural separation process for an enlarged range of industrial effluents. For a biomass concentration higher than 0.5 g/l, more than 95% of the cells were settled after 5 min; this fact shows that the auto-aggregation of yeast biomass is a rapid and efficient separation process. Cells inactivated at 45 °C maintain the sedimentation characteristics, while cells inactivated at 80 °C lose partially (40%) the flocculation.The passage of metal-loaded effluent through a series of sequential batches allowed, after the second batch, the reduction of the Ni2+concentration in solution for values below the legal limit of discharge of wastewater in natural waters (2 mg/l); this procedure corresponds to a removal of 91%. A subsequent batch had a marginal effect on Ni2+ removal (96%).Together, the results obtained suggest that the use of brewing flocculent biomass looks a promising alternative in the bioremediation of metal-loaded industrial effluents since the removal of the heavy metals and cell separation are simultaneously achieved.

Two high performance flow atomic absorption (HPF-AAS) related techniques were chosen to assess their suitability for the determination of several trace elements in complex environmental and biological samples. The technique selected were the Hydraulic High Pressure Nebulization Atomic Absorption Spectrometry (HHPN-AAS), and the Hydraulic High Pressure Nebulization Flame Furnace Atomic Absorption Spectrometry (HHPN-FF-AAS), which were applied directly, or after using off line liquid-liquid separation-preconcentration-back extraction procedures. Analytical methodologies were developed for Be, Sr, Ba, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Cd, Ag, Al, Tl, Pb, and Bi, for a variety of samples such as river and seawater, river and marine sediments, soft tissue of mussels, tunicate siphons, aquatic plants, and human samples of clinical interest such as placentas, umbilical cords, and cardiovascular tissues from surgical procedures. The analytical efficiency of the techniques was also proved in a proposed trace metal fractionation approach for river and seawater samples. All samples collected in this work were obtained from the North of Chile, where the most important economic activity is the mining industry.

Aluminium sulfate (alum), polyaluminium chloride (PACl) and magnesium chloride (MgCl2) have been used as coagulants with Koaret PA 3230 as the polyelectrolyte to determine the effectiveness of coagulation method for the removal of heavy metals (Pb, Zn and Fe). The maximum removal of Pb(II) was observed in different distinctive pH ranges: 6.2–7.8 for alum, 8.0–9.3 for PACl and 8.7–10.9 for