Nanometer titanium dioxide immobilized on silica gel as sorbent for preconcentration of metal ions prior to their determination by inductively coupled plasma atomic emission spectrometry.

In aqueous systems, heavy metal ions, when present in excess than permissible limits, are dangerous for human beings and aquatic life. Heavy metals cannot be degraded. Rather, they accumulate in living organisms either directly or through the food chain. Inside the body, metal ions can be converted to more toxic forms or can directly interfere with metabolic processes. As a result of metal toxicity, various disorders and damage due to oxidative stress triggered by metal ions have been witnessed. Toxic effects of metallic pollution coupled with the need of pure water for the survival and sanitation have thus prompted researchers to take every possible step to uphold the quality of water. In this regard, various strategies have been developed for the detection and the removal of metal ions from aqueous systems. Here we review metal-free water and methodologies used for rapid detection at low levels. Also, the application of benign materials and methods for metal removal from aqueous systems is detailed. Electrochemical methods, especially stripping and cyclic voltammetry, are commonly used methods for detection, while adsorption and ion exchange methods are quite effective for removal.

Detection and removal of heavy metal ions: a review

Heavy metal removal from waste waters by ion flotation

Thallium is released into the biosphere from both natural and anthropogenic sources. It is generally present in the environment at low levels; however, human activity has greatly increased its content. Atmospheric emission and deposition from industrial sources have resulted in increased concentrations of thallium in the vicinity of mineral smelters and coal-burning facilities. Increased levels of thallium are found in vegetables, fruit and farm animals. Thallium is toxic even at very low concentrations and tends to accumulate in the environment once it enters the food chain. Thallium and thallium-based compounds exhibit higher water solubility compared to other heavy metals. They are therefore also more mobile (e.g. in soil), generally more bioavailable and tend to bioaccumulate in living organisms. The main aim of this review was to summarize the recent data regarding the actual level of thallium content in environmental niches and to elucidate the most significant sources of thallium in the environment. The review also includes an overview of analytical methods, which are commonly applied for determination of thallium in fly ash originating from industrial combustion of coal, in surface and underground waters, in soils and sediments (including soil derived from different parent materials), in plant and animal tissues as well as in human organisms.

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Presence of thallium in the environment: sources of contaminations, distribution and monitoring methods

https://repositorio.ufba.br/ri/bitstream/ri/5067/1/separation_and__preconcentration.pdf

Separation and preconcentration procedures for the determination of lead using spectrometric techniques: a review.

Electrothermal atomic absorption spectrometric determination of cobalt, copper, lead and nickel traces in aragonite following flotation and extraction separation.

Flotation separation of cobalt and copper from fresh waters and their determination by electrothermal atomic absorption spectrometry

A fast method for separation of Cd, Cu, Fe, Ni, Pb, Zn, and Tl from seawater before their determination by atomic absorption spectrometry (AAS) is described. The ability of Co(III) hexamethylenedithiocarbamate, Co(HMDTC)3, as a flotation collector for metals from seawater was investigated. The influence of pH of the media, as one of the crucial parameters for effective flotation, as well as mass of cobalt as one of the constituents of a chelatometric collector was optimized. The used mode of atomization flame (FAAS) or electrothermal (ETAAS) depends on the concentration level of analyte present in the seawater sample investigated. The AAS method following flotation was compared with the method of inductively coupled plasma–atomic emission spectrometry (ICP–AES). The limit of detection (LOD) of each analyte obtained by FAAS or ETAAS is determined: flotation/ETAAS for Cd is 0.010 µg/L, for Cu 0.034 µg/L, for Ni 0.305 µg/L, for Pb 0.290 µg/L, and for Tl 0.032 µg/L, whereas flotation/FAAS for Fe is 0...

Atomic absorption spectrometry determination of Cd, Cu, Fe, Ni, Pb, Zn, and Tl traces in seawater following flotation separation

Determination of total thallium in fresh water by electrothermal atomic absorption spectrometry after colloid precipitate flotation.

Flame atomic absorption spectrometric determination of zinc after colloid precipitate flotation with hydrated iron(III) oxide and iron(III) tetramethylenedithiocarbamate as collectors.

Katarina Čundeva

Papers

Electrothermal atomic absorption spectrometric determination of cobalt, copper, lead and nickel traces in aragonite following flotation and extraction separation.

Flotation separation of cobalt and copper from fresh waters and their determination by electrothermal atomic absorption spectrometry

Atomic absorption spectrometry determination of Cd, Cu, Fe, Ni, Pb, Zn, and Tl traces in seawater following flotation separation

Determination of total thallium in fresh water by electrothermal atomic absorption spectrometry after colloid precipitate flotation.

Flame atomic absorption spectrometric determination of zinc after colloid precipitate flotation with hydrated iron(III) oxide and iron(III) tetramethylenedithiocarbamate as collectors.