presence of heavy metals in the aquatic systems has become a serious problem. as a result, therehas been a great deal of attention given to new technologies for removal of heavy metal ions from contaminated waters. adsorption is one of the effective methods for removal of toxic heavy metal such as chromium (vi). in the present study, adsorbent is prepared from rice husk, a low cost by product f...

A compact nucleated precipitation technology using two fluidised sand columns in series was developed to pretreat model metal-plating wastewater containing high concentrations of Cu(II) and Cr(VI). Since either Cu(II) precipitation or Cr(VI) co-removal with Cu(II) precipitation was found to be highly pH dependent in batch tests, the continuous-flow studies were conducted under different pHs. Ex...

The objective of this study is to investigate the removal efficiency of Cr(VI) by Bacillus subtilis, Pseudomonas aeruginosa and Enterobacter cloacae from aqueous solution under different process conditions. Batch mode experiments were carried out as a function of solution pH, biosorbent dosage, Cr(VI) concentration and contact time. The FT-IR spectra and SEM analysis of the biosorbent were reco...

Removal of Cr(VI) from aqueous solution was studied using charred pomegranate fruit waste [CPW] as a new low cost biosorbent under batch method at room temperature. Its efficiency for removal of Cr(VI) was compared with raw pomegranate fruit waste[RPW]. Various sorption parameters such as contact time, initial concentration of Cr(VI) ion and effect of pH on the adsorption capacity of the biosor...

Chromium in its toxic Cr(VI) valence state is a common contaminant particularly associated with alkaline environments. A well-publicized case of this occurred in Glasgow, United Kingdom, where poorly controlled disposal of a cementitious industrial by-product, chromite ore processing residue (COPR), has resulted in extensive contamination by Cr(VI)-contaminated alkaline leachates. In the search...

Low cost activated carbon, prepared from saw dust of Ziziphus jujube by chemical activation with phosphoric acid (H3PO4) was characterized and utilized for the removal of Cr (VI) ions from aqueous solutions under different conditions of solution pH, contact time, initial concentration, carbon dose and temperature. Adsorption of Cr (VI) ions was found highly pH dependent that increased with decr...

To improve the removal efficiency of heavy metals from wastewater, the surface of a fungal biomass was modified to obtain a high-capacity biosorbent for Cr(VI) in wastewater. The effects of pH, initial concentration, and sorption time on Cr(VI) removal by polyethylenimine (PEI)-modified Phanerochaete chrysosporium were investigated. The biomass adsorption capacity was significantly dependent on...

Chromium through natural processes and human activities enters the air, soil and water. Chromium-resistant bacteria are capable of reducing toxic Cr(VI) to less toxic Cr(III). In this work, batch studies were conducted to evaluate the effect of environmental factors on the rate of Cr(VI) reduction from synthetic wastewater of metal plating industry by Bacillus cereus under aerobic conditions. T...

A Bacillus sp. strain (JH2-2), isolated from soil at an abandoned mine site, reduced Cr(VI) to Cr(III) under aerobic conditions. At pH 7, the strain reduced essentially all of the Cr(VI) in M9 minimal medium to Cr(III) at initial concentrations ≤50 mg Cr(VI) L−1 within 100 h. The X-ray diffraction pattern of the Cr(III) precipitate matched chromium (III) hydrogen phosphate (CrH2P3O10∙2H2O). The...

This study describes a simple, rapid method for sensing Cr(vi) using 5-thio-(2-nitrobenzoic acid) modified gold nanoparticles (TNBA-AuNPs) as a remover for Cr(iii) and as a sensor for Cr(vi). We discovered that TNBA-AuNPs were dispersed in the presence of Cr(vi), whereas Cr(iii) induced the aggregation of TNBA-AuNPs. Due to this phenomenon, TNBA-AuNPs can be used as a sorbent material for the r...