Aqueous Solution

An electrothermal vaporization (ETV) system useful for the analysis of solutions and slurries has been coupled with a sector-field inductively coupled plasma mass spectrometer (ICP–MS) equipped with an array detector. The ability of this instrument to record the transient signals produced for a number of analytes in ETV–ICP–MS is demonstrated. Detection limits for Mn, Fe, Co, Ni, Cu, Zn and Ga are in the range of 4–60 pg μL− 1 for aqueous solutions and in the low μg g− 1 range for the analysis of 10 mg mL− 1 slurries of Al2O3 powders. The dynamic ranges measured for Fe, Cu and Ga spanned 3–5 orders of magnitude when the detector was operated in the low-gain mode and appear to be limited by the ETV system. Trace amounts of Fe, Cu and Ga could be directly determined in Al2O3 powders at the 2–270 μg g− 1 level without the use of thermochemical reagents. The results well agree with literature values for Fe and Cu, whereas deviations of 50% at the 90 μg g− 1 level for Ga were found.

Swelling mica exhibits unique characteristics for purification of drinking water contaminated by heavy metals and for selective removal of Sr2+ and Ba2+ ions from nuclear waste solution. As a new approach to recycle fly ash, conversion of fly ash to swelling mica has been attempted and ion-exchange properties of fly ash-derived swelling mica (referred to hereinafter as FA-swelling mica) were

The combination of UV irradiation and hydrogen peroxide (UV–H2O2) was shown to be effective in treating water spiked with 2,2′,4,4′,5,5′-hexachlorobipheny (PCB 153), reducing its concentration by as much as 98%. To test the toxicity of the effluent, bioassays involving three species of primary producers were performed. Results showed the effluent exerting an adverse effect on the algae Scenedesmus bijugatus and

The removal of fluoride from aqueous solution by using the original and activated red mud forms was studied in batch equilibration technique. Influence of pH, adsorbent dose and contact time on the adsorption were investigated. The fluoride adsorption capacity of activated form was found to be higher than that of the original form. The maximum removal of fluoride ion was obtained at pH 5.5. The removal of fluoride was expressed with Langmuir and Freundlich isotherms. Langmuir adsorption isotherm curve was found to be significant. It was found that the sufficient time for adsorption equilibrium of fluoride ions is 2 h. The possibility of removal of fluoride ion by using red mud is explained on the basis of the chemical nature and specific interaction with metal oxide surfaces and the results are interpreted in terms of pH variations.

It is well known that boric acid exhibits various toxic effects on plant, animal and human beings even at very low concentrations. Thus, the development of boron-removal technique from wastewater has been intensively investigated. In this study, a new hydrothermal treatment technique was developed to recover boron as recyclable precipitate Ca(2)B(2)O(5).H(2)O from aqueous solutions. As a result, it was found that the hydrothermal treatment using calcium hydroxide as a mineralizer converted boron in the aqueous media effectively into calcium borate, Ca(2)B(2)O(5).H(2)O. In the optimal hydrothermal condition, more than 99% of boron was collected from the synthetic wastewater of 500 ppm. Thus, the present hydrothermal treatment in the presence of calcium hydroxide is recommended as one of the effective techniques to recover boron from aqueous media.

This paper presents the possibility of removing metal ions by applying the hybrid complexation–ultrafiltration process. The research was conducted on model solutions containing Zn(II) and Ni(II) ions. The complexing agent applied in the research was sodium ...