Highly efficient removal of trace thallium from contaminated source waters with ferrate: Role of in situ formed ferric nanoparticle.

Title Highly efficient removal of trace thallium from contaminated source waters with ferrate: Role of in situ formed ferric nanoparticle.
Authors Y. Liu; L. Wang; X. Wang; Z. Huang; C. Xu; T. Yang; X. Zhao; J. Qi; J. Ma
Journal Water Res
DOI 10.1016/j.watres.2017.07.051
Abstract

Thallium (Tl) is highly toxic to mammals and relevant pollution cases are increasing world-widely. Convenient and efficient method for the removal of trace Tl from contaminated source water is imperative. Here, the removal of trace Tl by K2FeO4 [Fe(VI)] was investigated for the first time, with the exploration of reaction mechanisms. Six different types of water treatment agents (powdered activated carbon, Al2(SO4)3, FeCl3, ?-MnO2, MnO2 nano-particles, and K2FeO4) were used for the removal of Tl in spiked river water, and K2FeO4 showed excellent removal performance. Over 92% of Tl (1 ?g/L) was removed within 5 min by applying 2.5 mg/L of K2FeO4 (pH 7.0, 20 °C). XPS analysis revealed that in the reaction of Tl(I) with K2FeO4, Tl(I) was oxidized to Tl(III), and removed by the K2FeO4 reduced ferric particles. The removal of Tl by in situ formed and ex situ formed ferric particle was examined respectively, and the results revealed that the removal of trace Tl could be attributed to the combination of adsorption and coprecipitation processes. The hydrodynamic size of the reduced particle from K2FeO4 ranged from 10 nm to 100 nm, and its surface was negatively charged under neutral pH condition. These factors were conducive for the efficient removal of Tl by K2FeO4. The effects of solution pH, coexisting ions (Na(+), Ca(2+), and HCO3(-)), humic acid, solution temperature, and reductive environment on the removal and desorption of Tl were investigated, and the elimination of Tl in polluted river water and reservoir water was performed. These results suggest that K2FeO4 could be an efficient and convenient agent on trace Tl removal.

Citation Y. Liu; L. Wang; X. Wang; Z. Huang; C. Xu; T. Yang; X. Zhao; J. Qi; J. Ma.Highly efficient removal of trace thallium from contaminated source waters with ferrate: Role of in situ formed ferric nanoparticle.. Water Res. 2017;124:149157. doi:10.1016/j.watres.2017.07.051

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Thallium

See more Thallium products. Thallium (atomic symbol: Tl, atomic number: 81) is a Block P, Group 13, Period 6 element with an atomic weight of 204.38. Thallium Bohr ModelThe number of electrons in each of thallium's shells is 2, 8, 18, 32, 18, 3 and its electron configuration is [Xe] 4f14 5d10 6s2 6p1. The thallium atom has a radius of 170 pm and a Van der Waals radius of 196 pm. Thallium was discovered by Sir William Crookes in 1861 and first isolated by Claude-Auguste Lamy in 1862. Thallium is a post-transition metal that is not found free in nature. Thallium is primarily used for its electrical conductivity as thallium sulfide, which changes with exposure to infrared light. This ability makes the compound useful in photocells. Elemental ThalliumThallium bromide-iodide crystals have been used as infrared optical materials. Thallium has also been used with sulfur, selenium or arsenic to produce low melting glasses which become fluid between 125 and 150 °C, while thallium oxide has been used to produce glasses with a high index of refraction, and is also used in the manufacture of photo cells. Its name is derived from the Greek word thallos, which means twig or green shoot.

Iron

See more Iron products. Iron (atomic symbol: Fe, atomic number: 26) is a Block D, Group 8, Period 4 element with an atomic weight of 55.845. The number of electrons in each of Iron's shells is 2, 8, 14, 2 and its electron configuration is [Ar] 3d6 4s2. Iron Bohr ModelThe iron atom has a radius of 126 pm and a Van der Waals radius of 194 pm. Iron was discovered by humans before 5000 BC. In its elemental form, iron has a lustrous grayish metallic appearance. Iron is the fourth most common element in the Earth's crust and the most common element by mass forming the earth as a whole. Iron is rarely found as a free element, since it tends to oxidize easily; it is usually found in minerals such as magnetite, hematite, goethite, limonite, or siderite.Elemental Iron Though pure iron is typically soft, the addition of carbon creates the alloy known as steel, which is significantly stronger.

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