Using ground granulated blast-furnace slag (GGBS) under different alkaline conditions, we studied the mechanisms and extents of Cr(VI) reduction and sorption and compared them to reactions with Portland cement (PC). We also investigated the effects of mixing PC/GGBS ratios on Cr(VI) dissolution after carbonating the substrates. We observed a complete sorption and reduction of Cr(VI) to Cr(III) ...

background plasmid-mediated quinolone resistance genes (pmqr) have been shown to play not only an important role in quinolone resistance, but also resistance to other antibiotics, particularly β-lactams and aminoglycosides. these genes are mainly associated with clinical isolates of enterobacteriaceae. however, detection of pmqr genes in the community isolates can increase the dissemination rat...

A simple method using solid-phase extraction combined with metal furnace atomic absorption spectrometry was developed for the determination of Cr(III) and Cr(VI) at sub-ppb levels in water. A 500-ml water sample was adjusted to pH 3 with nitric acid and then passed through an iminodiacetate extraction disk placed on a cation-exchange extraction disk at a flow rate of 20-40 ml min(-1) for concen...

A new method involving pre-concentration on modified silica fiber is described for the speciation of chromium(III) [Cr(III)] and chromium(VI) [Cr(VI)] in aqueous media. This method is based on the different chelating behavior of Cr(III) and Cr(VI) with morpholine-4-carbodithioate (MDTC). Both complexes are extracted on silica fiber modified by sol-gel technology by using 3-aminopropyltriethoxys...

Cr(VI) is a highly toxic metal ion and considered a priority pollutant released from various chemical industries. Treatment methods to remove Cr(VI) from water and wastewater include chemical precipitation, ion exchange, membrane separation, electro-coagulation and reduction. These methods are not economically viable for large scale treatment of wastewater that is rich in Cr(VI). Adsorption is ...

A chromate-removing strain was isolated from spent chrome effluent and identified as Bacillus circulans strain MN1. The isolated strain was studied for resistance to Cr (VI) and its ability to remove Cr (VI). The strain was found to tolerate Cr (VI) concentration as high as 4500 mg/L, but the cells growth was heavily influenced when initial Cr (VI) concentration was increased between 1110 mg/L ...

A hybrid adsorbent (FOAE) prepared by loading ferric oxyhydroxide on anion exchanger was applied for adsorptive removal of Cr(VI) from water. Effects of initial Cr(VI) concentration, pH, temperature and competition of other anions on Cr(VI) adsorption were investigated in batch experiments. The equilibrium adsorption capacity (Qe) of the FOAE increased with initial Cr(VI) concentrations (from 2...

background: the presence of heavy metals in the environment especially in water supplies have caused many concerns because of their toxicity and non-degradability. hexavalent chromium (cr) is one of the most toxic metals which is used in many industries, so it is essential to remove it from industrial wastewater. in this study, we made a comparison between different adsorption isotherms in the ...

AIMS Most of the researches investigating immobilized fungi in chromate [Cr(VI)] bioremediation have used dead cells to adsorb Cr(VI). Therefore, the aim was to identify a Cr(VI)-reducing fungus with the ability of reducing the toxic Cr(VI) into the much less toxic Cr(III) and to apply the immobilized living fungus in continual reduction of Cr(VI). METHODS AND RESULTS Cr(VI) reduction occurre...

Polystyrene (PS) was extracted from Styrofoam (expanded polystyrene foam) waste, so called white pollutant. The PS was functionalized with N,NBis(2-aminobenzylidene)benzene-1,2diamine (ABA) ligand through an azo spacer. The resin was characterized by FT-IR spectroscopy and elemental analysis. The PSN=N-ABA resin was used for the enrichment and speciation of Cr(III)/Cr(VI) ions and total Cr dete...