Chromium-zinc ferrite nanocomposites for the catalytic abatement of toxic environmental pollutants under ambient conditions.

Title Chromium-zinc ferrite nanocomposites for the catalytic abatement of toxic environmental pollutants under ambient conditions.
Authors D.S. Nair; M. Kurian
Journal J Hazard Mater
DOI 10.1016/j.jhazmat.2017.11.045
Abstract

Catalytic abatement of 4-chlorophenol, 2,4-dichlorophenol and 2,4-dichlorophenoxy acetic acid in water was investigated by peroxide oxidation over chromium substituted zinc ferrite nanocomposites at ambient conditions. The structural and chemical properties of composites synthesized by sol-gel auto combustion method was studied by X-ray diffraction, Fourier Transform Infra-Red spectroscopy, Transmission Electron Microscopy, surface area, X-ray Fluorescence spectroscopy, Temperature Programmed Reduction and Desorption techniques. Complete removal of 4-CP, DCP and 2,4-D was achieved within 60, 75 and 90min with 96.7/90.5%, 93.88/77.23% and 88.55/62.1% of COD/TOC removal respectively at 298K and 343K. Influence of reaction variables including reaction temperature, oxidant concentration, substrate concentration, catalyst dosage and its composition on the removal efficiency was studied. Kinetic study revealed that wet peroxide oxidation followed a first order kinetic model with rate constant and activation energy of 3.5×10-2min-1/10.7kJ/mole, 9.5×10-3min-1/12.9kJ/mole and 2.29×10-2min-1/17.7kJ/mole respectively for 4-CP, DCP and 2,4-D. The results of five consecutive catalytic runs from X-ray diffraction, Brunauer Emmet Teller surface area and leaching studies from Atomic Absorption Spectrophotometry (AAS) revealed the excellent stability of the catalyst. Scavenging effect of n-butanol on hydroxyl radical indicated a heterogeneous free radical mechanism.

Citation D.S. Nair; M. Kurian.Chromium-zinc ferrite nanocomposites for the catalytic abatement of toxic environmental pollutants under ambient conditions.. J Hazard Mater. 2018;344:925941. doi:10.1016/j.jhazmat.2017.11.045

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See more Chromium products. Chromium (atomic symbol: Cr, atomic number: 24) is a Block D, Group 6, Period 4 element with an atomic weight of 51.9961. Chromium Bohr ModelThe number of electrons in each of Chromium's shells is 2, 8, 13, 1 and its electron configuration is [Ar] 3d5 4s1. Louis Nicolas Vauquelin first discovered chromium in 1797 and first isolated it the following year. The chromium atom has a radius of 128 pm and a Van der Waals radius of 189 pm. In its elemental form, chromium has a lustrous steel-gray appearance. Elemental ChromiumChromium is the hardest metallic element in the periodic table and the only element that exhibits antiferromagnetic ordering at room temperature, above which it transforms into a paramagnetic solid. The most common source of chromium is chromite ore (FeCr2O4). Due to its various colorful compounds, Chromium was named after the Greek word 'chroma.' meaning color.

Zinc

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Iron

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