Although electrodeposition of chromium has heen practiced for 75 years, the mechanism is still open to conjecture. Par t of the reason is the complexity of the chemistry ofchromic acidand its existencetnaqueoussolutionin the form of coordinated octahedral complexes. These complexes vary both structurally and kinetically a t different CrO, concentrations. Thechemistryoftriand hexavalent Chromium...

Metal-on-metal bearings for total hip replacements have been introduced as an alternative to polyethylene in young and more active patients. These have, however, been shown to be prone to implant malpositioning and have been limited by some specific design features. In that context, coatings present an option to increase wear resistance by keeping the high fracture strength of the metal substra...

During the past several years, waste produced by the electroplating industry has attracted attention due to the level of pollutants found in the waste stream, the difficulty associated with treatment, and the cost of waste disposal. EPA has enacted regulations to control the discharge from plating facilities and estimates that 140 million lb of metal pollutants will be prevented from being disc...

As a main part of hydraulic cylinder, the piston rod is used in tough surrounding and corrosive condition; consequently a high quality protecting layer is essential. Currently EHC, electroplating hard chromium (hard chrome) is a widespread method for piston rod due to powerful performance and low cost. Unfortunately the plating process contains hexavalent chromium (Cr) which is toxic and carcin...

Chromium-rich electroplating sludge (CRES) is a hazardous solid waste with high content of moisture requiring efficient drying before subsequent treatment. In this study, the microwave kinetics CRES were examined. The results showed that had good absorptivity, contributing to much shorter time and better performance compared conventional drying. comparison at 105 °C, 600 W for total removal was...

Potential human exposure to airborne metals occurs in a broad number of government and civilian operations and processes. Included among these are hard chromium plating, firing ranges, metallurgy and metals processing, lead paint abatement, and decontamination and decommissioning activities at hazardous waste sites. Effective control of these fugitive emissions requires sensitive real time moni...

Chromium, especially the hexavalent form, is toxic to humans. Industries like chrome plating, textile, electroplating discharge Cr(VI) in their effiuents. Wastes containing chromium are environmentally persistent and toxic, and cannot be degraded or detoxified biologically. Various techniques developed for the removal of heavy metals include chemical precipitation, ion exchange and adsorption. ...

This work reports a study of the extraction and recovery of chromium from the wastes (class I dangerous) generated by a galvanic manufacturer. Commercial HCl at room temperature was employed, and the conditions of the extraction process were optimized according to a sequential experimental design, which also included the acid concentration and contact time as variables. The best extraction cond...