Tailings deposits from gold and uranium (U) mining in the Witwatersrand basin often contain elevated levels of radioactive and chemo-toxic heavy metals. Through seepage, dissolved U and other metals migrate from tailings deposits via groundwater into adjacent fluvial systems. The subsequent transport through flowing surface water is one of the most effective pathways of distributing contaminant...

Anthropologic activities have transformed global biogeochemical cycling of heavy metals by emitting considerable quantities of these metals into the atmosphere from diverse sources. In spite of substantial and progressive developments in industrial processes and techniques to reduce environmental emissions, atmospheric contamination by toxic heavy metals and associated ecological and health ris...

The humic substances including humic acid (HA) and fulvic acids (FAs) extracted from a refuse compost were investigated the average conditional concentration quotients of the complexes formed by the reaction of heavy metals with the humic substances. The characteristics of these humic substances were previously investigated by a related study. The concentrations of the free ions of Pb, Cu, Cd, ...

Distribution and availability of heavy metals to plants is important when assessing the environmental quality of an area. The objectives of this study conducted in 2002 were: a) determine the levels of the heavy metals cadmium (Cd), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni) and zinc (Zn) in the agricultural soils of the Bursa plain so that the degree of pollution could be ascertained,...

Not all heavy metals are toxic. Some at lower concentrations are essential to the physiological status of the organism. Under certain conditions, induced toxicity occurs when the heavy metals are in the form of cations which tends to bind to certain biomolecules, thus becoming toxic to organisms. In many industries, toxic heavy metals such as As, Cd, Cr, Cu, Hg, Pb and Zn, are released mainly i...

Heavy metals affect the biochemical reactions that take place during anaerobic digestion processes of organic matter. In this review, the different effects observed in anaerobic digestion processes and during the production of biomethane and biohydrogen from several substrates contaminated with and/or inheriting heavy metals from the substrates themselves were discussed. It has been found that ...

Removal of heavy metals from wastewater needs advance chemical technology and is more expensive too. The cheaper alternative for this is the bioremediation using heavy metals resistant microorganisms. In this study, 10 heavy metal resistant bacteria were isolated from oxidation ditch of wastewater treatment plant of Bagmati Area Sewerage Project. These include chromium resistant Staphylococcus ...

It is obvious that heavy metals toxicity to humans is as a result of long term or extreme level exposure to pollutants common in the environment including the air, water, food and many consumer products like the cosmetics and toiletries .In this study, we measured the levels of toxic metals in different hair dye products sold at local shops in Baghdad, Iraq. The hair dyes included twelve sample...

Overlying water, sediment, rhizosphere sediment and mangrove seedlings in the Futian mangrove forest were analyzed for heavy metals. The results showed that mangrove plant acidified sediment and increased organic matter contents. Except for chromium (Cr), nickel (Ni) and copper (Cu) in Aegiceras corniculatum sediment, heavy metals in all sediments were higher than in overlying water, rhizospher...

This study aimed to evaluate the concentration of heavy metals in liquid effluents and to quantify the mercury content in dental amalgam waste generated by dental clinics. Three neighbouring cities in Northeast Algeria were considered in this study (Constantine, Skikda, and Annaba). Heavy metals, such as Hg, Cu, Zn, Fe, Ni, Mn, Cr, Cd, and Pb, were analysed in wastewater and then compared with ...