We investigate the single-cell reduction of toxic Cr(VI) by the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 (MR-1), an important bioremediation process, using Raman spectroscopy and scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX). Our experiments indicate that the toxic, highly soluble Cr(VI) can be efficiently reduced to less to...

In this study, Fe(III)-cross-linked chitosan beads (Fe(III)-CBs) were synthesized and employed to explore the characteristics and primary mechanism of their hexavalent chromium (Cr(VI)) adsorption under low concentration Cr(VI) (less than 20.0 mg l-1) and a pH range from 2.0 to 8.0. Batch tests were conducted to determine the Cr(VI) adsorption capacity and kinetics, and the effects of pH and te...

The removal of crystal violet from aqueous solution by NiFe2O4 magnetic nanoparticles treated with sodium dodecyl sulfate was investigated. The modified magnetic nanoparticles were prepared by chemical reaction of a mixture of Ni+2 and Fe+3 ions mixture in aqueous solution at the presence of ammonia and then sodium dodecyl sulfate was utilized as an ionic surfactant to modified the obtained mag...

Chromium is abundant in nature and has a dominant presence in most of the effluent streams as compared to other heavy metal ions. The presence of highly toxic and carcinogenic hexavalent chromium (Cr(VI)) in effluent streams is a major environmental issue. The electroplating and tannery industry effluents are the major source for the Cr(VI) production in wastewater streams. The present work dea...

Nickel (Ni) as a heavy metal due to its toxicity should be removed from wastewater and aquatic environments  using  efficient  technology.  The  aim  of this  study  was  to  remove  Ni  from  an aqueous  solution  using  palm  leaf  ash  produced  in  a  furnace.  To  do  so,  kinetic  and thermodynamic experiments were conducted on the adsorption process. Moreover, the effect of time, pH, ads...

The pollutant Cr(VI) is known to be very carcinogenic. In conditions of excess of Cr(VI), oxidation of D-galacturonic acid (Galur), the major metabolite of pectin, yields d-galactaric acid (Galar) and Cr(III). The redox reaction takes place through a multistep mechanism involving formation of intermediate Cr(II/IV) and Cr(V) species. The mechanism combines one- and two-electron pathways for the...

the potential of heat inactivated saccharomyces cerevisiae in the bioremoval and reduction ofcr (vi) ions from wastewaters was evaluated in terms of metal uptake in time and at equilibrium, andbiosorption efficiency, by varying ph, biosorbent doses, contact time and temperature, in batch mode. during the sorption process, the heat inactivated biomass of the yeast saccharomyces cerevisiae is cap...

A hierarchical porous carbon obtained from pig bone (HPC) was utilized as the adsorbent for removal of Cr(VI) from aqueous solution. The effects of solution pH value, concentration of Cr(VI), and adsorption temperature on the removal of Cr(VI) were investigated. The experimental data of the HPC fitted well with the Langmuir isotherm and its adsorption kinetic followed pseudo-second order model....