Major joining methods of dental casting metal include brazing and laser welding. However, brazing cannot be applied for electroformed metals since heat treatment could affect the fit, and, therefore, laser welding is used for such metals. New methods of joining metals that do not impair the characteristics of electroformed metals should be developed. When new coating is performed on the surface...

Our study was based on the recent increase in wastewater pollution and its deleterious effects to the marine ecosystem. Using numerical simulation (DESCAR3.2 software program), we investigated the orientation and quantification of trace metals in wastewater discharges from permanent and semi-permanent drain outfalls constructed along the Kuwait Coastline encompassing six Kuwait Governorates (GI...

Industrial effluent containing heavy metals discharged into streams may pose high toxicity risks to aquatic organisms and to human health. Therefore, it is important to understand how to change the amount of effluent with heavy metals discharged from industries into open aquatic ecosystems both for effective management of heavy metals and to foster sustainable ecosystems. This study was conduct...

The process of etching is the most crucial part of the work of manufacturing printed circuit boards (PCB). In the etching process by nitric acid, a spent etching waste solution of composition 250 g/L HNO3, 30-40 g/L Cu, 30-40 g/L Sn, 30-40 g/L Pb and 20-25 g/L Fe is produced. High metal concentrations in the spent etching waste solution make it a viable candidate for the recovery of metals. Rec...

The toxicity of all atomically stable metals in the periodic table, excluding Na, Mg, K, and Ca, was measured in one-week exposures using the freshwater amphipod Hyalella azteca in both Lake Ontario, Canada, and soft water (10% Lake Ontario). Metals were added as atomic absorption standards (63 metals), and also as anion salts for 10 metals. Lethal concentrations resulting in 50% mortality (LC5...

The concentrations of Cd, Pb, Ni, Cr, Cu, Co, Fe, Mn, Zn, Mg, Ca, K, and Na were determined in some traditional alcoholic beverages (oil palm wine, raphia palm wine, burukutu, pito, ogogoro) consumed in southern Nigeria, with a view to providing information on the dietary intakes of essential metals and exposure of humans to toxic metals. The concentrations of these 13 elements were determined ...

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 ...

BACKGROUND This study was conducted to estimate the level of heavy metals accumulate in vegetables irrigated with contaminated water compared with those irrigated with fresh water in Hamadan, west of Iran in 2012. METHODS Sixty samples of different vegetables i.e., parsley, tarragon, sweat basil and leek irrigated with contaminated water and thirty six samples from three different adjacent ar...

Metals make up the bulk of the periodic table and range from the very light (e.g., beryllium) to the very heavy (e.g., the actinides). Metals are important constituents of life, drive economic activity and industry, but can also be a hazard to human health. The metals can be roughly divided into three groups. The first being those metals, such as iron and zinc, that are essential to human life ...