Methods of absorbing thalli

Background and Objective: Thallium (Tl) is a toxic and rare heavy metal. It is more acutely toxic to humans than other heavy metals. TI may incease in the environment by activities likemining and farming and it may enter the food chain as a hidden health killer , leading to a variety of adverse effects on the health, even at a low concentration, owing to its acute and chronic poisoning .Tl(I) is more common in water/wastewater. Tl(I) has low affinity to normal materials and has high solubility and mobility in water and the removal of Tl(I) is so difficult . At present, several techniques for removing Tl from wastewater have been applied; one of these methods is adsorption.Materials and Methods: Pubmed and google scholar were used for comprehensive searches for articles published from ۱۹۹۶ to ۲۰۲۰. Keywords included thallium, similarities between thallium and potassium, removing and absorbing thallium. We selected the articles based on the title and abstract. Finally, we found ۶ articles with our selection criteria.Results: The first method is the adsorption of Prussian blue analogs and Tl(۱) is absorbed by PB and Fe۴(III). This adsorption uses the ion exchange mechanism and increases dramatically with increasing the pH of adsorption of this element. Bioabsorption is another method of adsorption. This method changes the absorption range of Tl(۱) by changing the pH range. Adsorbents of this group usually consist of hydroxyl, carboxyl, etc. In this method, the necessary force is provided to bind Tl(۱) to the adsorbents through ion exchange. Metal oxides are another method. One of the disadvantages of this method is the incomplete removal of Tl(۱) and despite the good adsorption capacity, they have poor selectivity. Macrocyclic compounds are the best methods of adsorption of Tl(۱). This method, unlike the metal oxide method, has high selectivity. Crown ether is one of the macrocyclic compounds that has given the best response in the absorption of Tl(۱). This high performance is due to the high compatibility of Tl(۱) with a cavity size of ۱۸C۶, which leads to the creation of the most stable complexes with this ether. Conclusion: Thallium will be a Common pollutant of aquatic environments. Adsorbents like biosorbents, metal oxides such as hydrous iron oxide, superparamagneticFe۳O۴, etc have been developed but The absorption of thallium by these adsorbents is affected by coexisting cations. macrocyclic compounds are very useful for removing thallium Even in the presence of coexisting cations. Recommended in future studies that ways to improve the performance of each thallium adsorbent be investigated.

کلیدواژه ها:

thallium ، similarities between thallium and potassium ، removing and absorbing thallium