Annually, a large amount of effluents is discharged from an industrial zone dedicated to leather industries into a dried seasonal waterway bed in Mashhad plain, Northeast of Iran. These soils are high in pH, CaCO contents and have no naturally occurring chromium detectable in mg/kg range. Considering high 3 concentration of chromium in the discharged leather industries effluents and their direc...

Quantitative electron microscopy was used to evaluate interactive effects of chromium additions and phosphate nutrient status on the diatom Cyclotella meneghiniana. Cells of differing phosphate status were exposed to hexavalent chromium for 7 days and morphological changes in both phosphate alone and phosphate and chromium treatments were observed. Changes in chloroplast relative volume and num...

Microstructural features of sputtered chromium and chromium-50 wt. % platinum thin films on carbon substrates are presented. Films produced by rf sputtering and dc magnetron sputtering are compared using analytical electron microscopy techniques. All rf-sputtered films are uniform in chemistry and thickness and are amorphous. The chromium film became crystalline with a grain size ofless than 10...

We report the growth of high density silicon Oxide (SiOx) nanowires at an elevated temperature. The nanowires density is enhanced by inserting a thin layer of chromium metal in gold/Si catalyst system. The SiOx nanowires were grown with gold/chromium catalysts stack layer on the Si substrate at different temperatures ranging from 1050oC to 1150oC. Under the catalysis reaction of the gold/chromi...

Several low cost biomaterials such as rice husk, sugar cane bagasse, Tulsi Leaf &branches, coconut shell & coir and fly ash were tested for removal of chromium. All the experiments were carried out in batch process. The adsorbent, which had highest chromium (VI) removal, was coconut shell. An influence of chromium concentration, contact time on removal of chromium from effluent was investigated...

Joint effect of chromium and titanium on structure and properties of hard castings is investigated in present work. It is determined that titanium neutralizes carbide-forming effect of chromium in the investigated concentration intervals. In the presence of titanium, the effect of chromium on hardness of samples is lower as compared to its individual effect. Therefore, addition of only chromium...

Estimation of water soluble hexavalent chromium and total chromium has been devised. For the complete extraction of water soluble hexavalent chromium, leaching period of five days is done. It was ascertained that complete extraction was achieved in five days; the total chromium determination in these samples was done by fusing sample with sodium carbonate up to 1050 C in muffle furnace. Chromiu...

Chromic oxide is an important basic chemical and finds many applications including metallurgical materials, green pigments, construction materials, refractory materials and catalysts. Presently, the industrial production of chromic oxide generally employs two processes (Ding, 2003): one is the reduction of sodium dichromate with ammonia sulfate; the other is the thermal decomposition of chromic...

Absorptive characteristics of polyaniline synthesized in mixture of water and acetonitrile in 50/50 volume ratio was studied. Synthesized polyaniline in powder shape is used as an adsorbent to remove toxic hexavalent chromium from aqueous solutions. Experiments were conducted in batch mode with different variables such as agitation time, solution pH and initial concentration of hexavalent chrom...

The removal of the chromium (VI) ion from aqueous solutions with the Lewatit FO36 ion-exchange resin is described at different conditions. The effects of adsorbent dose, initial metal concentration, contact time and pH on the removal of chromium (VI) were investigated. The batch ion exchange process was relatively fast and it reached equilibrium after about 90 min of contact. The ion exchange p...