Method for Decontamination of Toxic Aluminochrome Catalyst Sludge by Reduction of Hexavalent Chromium

Abstract

The article is devoted to the neutralization of the harmful effects of aluminochrome catalyst sludge. Catalyst sludge is a waste product from petrochemical production and poses a serious threat to the environment and humans because of the toxic hexavalent chromium it contains. The emissions of Russian petrochemical enterprises’ alumochrome sludge is 10,000–12,000 tons per year. In this paper, research related to the possibility of reducing the harmful effects of sludge by converting hexavalent chromium to a less dangerous trivalent state is presented. The reduction of hexavalent chromium was carried out with different reagents: Na2SO3, FeSO4, Na2S2O3, and Na2S2O5. Then, a comparative analysis was carried out, and sodium metabisulfite was chosen as the most preferred reagent. The peculiarity of the reducing method was carrying out the reaction in a neutral medium, pH = 7.0. The reduction was carried out in the temperature range of 60–85 °C and under standard conditions. The maximum recovery efficiency of chromium from the catalyst sludge (100%) was achieved at 85 °C and 10 min. This method did not involve the use of concentrated sulfuric acid, as in a number of common techniques, or additional reagents for the precipitation of chromium in the form of hydroxide.

Conjugated microporous polymer with matched energy band structure as photocatalyst for simultaneous removal of heavy metal ion and organic pollutant

“…5–8 It is environmentally friendly technology that can efficiently treat harmful heavy metals and organic pollutants contaminated in wastewater and convert them into less toxic compounds. 9–14 Traditionally, photocatalysis has utilized semiconductor materials (TiO 2 , ZnO) as catalysts; these materials exhibit several limitations such as a low sunlight utilization rate and high photogenerated carrier recombination rate, which lead to unsatisfactory photocatalytic efficiency. 15–17 In addition, photocatalysts that can simultaneously reduce heavy metals and oxidize to degrade organic pollutants are still very scarce, 18 because it is difficult to meet the conduction and valence band requirements for photocatalysis at the same time.…”

Integral Assessment of Influence Mechanism of Heavy Particle Generator on Hydrocarbon Composition of Vehicles Motor Fuel

“…To search the individual hydrocarbon composition of light motor fuels (petrol, paraffin, diesel fuel), the method of gas chromatography-mass spectrometry (GC-MS) is quite effective. This method allows identifying up to 95-100 % of individual compounds (9)(10)(11). When using fuel, a group of similar compounds in its composition behaves similarly and affects certain quality parameters (12,13).…”