A method for the preconcentration and speciation of chromium in seawater was developed. On-line preconcentration and determination were carried out by using inductively coupled plasma atomic emission spectrometry (ICP-AES) with dual mini-columns containing a chelating resin. In this system, Cr(III) was collected on the first column. The effluent containing residual chromium from the first colum...

the potential of citrobacter freundii, a gram negative bacteria for the remediation of hexavalentchromium (cr(vi)) and trivalent chromium (cr(iii)) from aqueous solutions was investigated. bioremediationof cr(vi) involved both biosorption and bioreduction processes, as compared to only biosorption processobserved with respect to cr(iii) bioremediation. in the case of cr(vi) bioremediation studi...

crown ethers 12-crown-4 (12c4), benzo-15-crown-5 (b15c5), 18-crown-6 (18c6), nitrobenzo-18-crown-6 (nb18c6) dibenzo-18-crown-6 (db18c6) and dicyclohexyl-18-crown-6 (dc18c6), dissolved in dichloromethane, are able to form oxonium-ion complexes in contact with aqueous sulfuric and hydrochloric acid solutions. this ability allows the transfer of cr(vi) oxanions from the acid media, through an orga...

A new chelating material from mercerized cotton linter was prepared by a reaction with succinic anhydride in the presence of toluene/triethylamine and a 4-dimethylaminopyridine catalyst, followed by reacting with Fe(III) to obtain the final product. The materials were characterized by Fourier transform infrared spectrometry, scanning electron microscopy, and energy dispersive spectrometer; the ...

Hexavalent chromium [Cr(VI)] and ozone are produced in many arc-welding processes. Cr(VI) is formed when welding with chromium-containing alloys and is a suspected carcinogen. Ozone is formed by the action of ultraviolet light from the arc on oxygen and can cause severe irritation to the eyes and mucous membranes. Previous work has demonstrated that reduction of sodium and potassium in manual m...

Marine seaweed (Eucheuma sp.) associated strains of Aspergillus flavus and Aspergillus niger were tested for their Cr(VI) tolerance. Both the isolates showed luxuriant growth in different concentrations of Cr(VI), i.e., 25, 50 and 100 ppm. There was no marked variation in the dry weight of control and test isolates, which indicated that both the isolates can tolerate a wide range of hexavalent ...

conclusions p. aeruginosa and s. marcescens can be good candidates for the detoxification of cr (vi) in soltan abad river. results the results indicated that pseudomonas aeruginosa and serratia marcescens were the most resistant bacteria with mics of 200 and 150 mg/l, respectively. both bacteria completely reduced 25 and 50 mg/l of cr (vi) in 36 hours and 48 hours, respectively. the growth rate...

Permeable reactive barriers containing zerovalent iron are being increasingly employed for in situ remediation of groundwater contaminated with redox active metals and chlorinated organic compounds. This research investigated the effect of chromate concentration on its removal from solution by zerovalent iron. Removal rates of aqueous Cr(VI) by iron wires were measured in batch experiments for ...

Chromium plays an important role in human and animal bodies. According to the oxidation state chromium can be advantageous for human health and, simultaneously possesses toxic properties. In this work the studies concerning the chromium content in the total and Cr (VI) forms in selected and frequently used during breakfast food products were presented. The largest quantities of the metal occur ...

The current investigation presents the role of gooseberry (Phyllanthus acidus) seeds as an effective biosorbent for remediating chromium (VI)), a toxic heavy metal pollutant commonly found in effluents from tanneries and relevant industries. Biosorption was affected by pH, temperature and initial metal concentration. Furthermore, there is a need to understand the holistic effect of all...