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.

Получены значения констант скорости и времени полуобмена ионообменной адсорбции перренат-ионов из растворов аммиачного выщелачивания сорбентами АВ-17-8, Purolite A103Plus и Purolite PPA100. Определенные коэффициенты диффузии свидетельствуют о гелевом механизме диффузии в сорбентах АВ-17-8, Purolite A103Plus и Purolite PPA100 при сорбции перренат-ионов из аммиачных растворов. The values of the rate and time constants of the semi-exchange of ion exchange adsorption of perrenate ions from solutions of ammonia leaching with sorbents AV-17-8, Purolite A103Plus and Purolite PPA100 were obtained. Certain diffusion coefficients indicate a gel diffusion mechanism in the sorbents AV-17-8, Purolite A103Plus and Purolite PPA100 during the sorption of perrenate ions from ammonia solutions.