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Vol. 23 (2020 year), No. 2, DOI: 10.21443/1560-9278-2020-23-2

Mosendz I. A., Kremenetskaya I. P., Drogobuzhskaya S. V., Alekseeva S. A.
Sorption of heavy metals by the filtering containers with serpentine materials

The search for effective technologies for the remediation of technologically polluted natural objects is an urgent problem of environmental protection. At the experimental site near Kola MMC JSC (Murmansk region, Monchegorsk), experiments have been carried out on the use of mining waste to create phyto-adsorption sites in technologically polluted territories. During the experiments, filtering modules were used to study the processes of sorption/desorption of emission components with vermiculite-sungulite composition materials obtained by enriching phlogopite mining waste (Murmansk Region, Kovdor). To load two types of filtering modules designed to study open (I) and partially open (II) systems, the authors have used the initial and heat-treated granular sungulite, as well as slurry products (the content of sungulite and vermiculite was 30 %). As a control option, an experiment has been carried out using pure peat, selected in the vicinity of Apatity (Murmansk region). As a result of the study, the layer-by-layer content of the acid-soluble (or semi-gross) form of the components has been determined; the toxicity module has been calculated (the ratio of the total molar content of metals (Cu + Ni) and macronutrients (Ca + Mg)) used to assess the possible toxic effect of products in relation to plants. Pure peat has proved to possess the greatest sorption ability, however, at the end of the experiment, the highest degree of toxicity has been observed for peat; mineral products have been the least toxic. An analysis of the distribution of metals among the layers of filtering modules (II) has shown that intense accumulation of metals is observed in the upper layers; with increasing depth (layers 2–4) there is a gradual decrease in the copper content, in some products nickel is leached in the lower layers. The results of the study have shown that for loading phyto-adsorption sites it is advisable to use a granular sungulite product characterized by good sorption ability and low toxicity.

(in Russian, стр.7, fig. 6, tables. 1, ref 10, AdobePDF, AdobePDF 0 Kb)

Vol. 24 (2021 year), No. 1, DOI: 10.21443/1560-9278-2021-24-1

Kremenetskaya I. P., Ivanova T. K., Gurevich B. I., Novikov A. I., Semushin V. V.
Separate deposition of metals from highly concentrated solutions with granulated magnesia-silicate reagent

Multi-stage deposition of metals from a sulfate solution with a high concentration of iron, aluminum, copper, zinc, and nickel has been studied. The concentrations of the components correspond to the composition of the sub-basement waters of the Gaisky GOK. Granular magnesia-silicate reagent based on serpentinite (Khalilovsk magnesite deposit, the Orenburg region, Russia) has been used as an alkaline agent. The magnesia-silicate reagent's ability to reduce the acidity of solutions is due to the presence of products of destruction of the original serpentine mineral, mainly magnesium oxide. The results of the solutions multi-stage purification from metals simulation have been presented. It has been found that the reagent did not wholly exhaust its activity during a single contact with the solution. Therefore, the possibility of its repeated use for the 2nd and 3rd time has been studied. As the solution is neutralized according to the known pH range of the beginning and complete deposition of metal compounds, first iron, and then aluminum are deposited. For copper and nickel, the effect of co-precipitation is observed until the pH of precipitation of poorly soluble compounds is reached. Iron is the main component of precipitations at the 1st, 2nd, and 3rd stages, which corresponds to pH = 2.4–3.7. At the 4th stage (pH = 4.0), the precipitations consisted mainly of aluminum compounds. The copper and nickel content in precipitations increase due to decreased concentration of major components (aluminum and iron) and a pH increase. The deposition of zinc from the solution occurs not to the precipitations, but on the granules surfaces. Precipitations enriched in aluminum and iron have been obtained. Sorption and co-precipitation processes have been observed for copper, zinc, and nickel, which prevents individual precipitation by these metals. Thermally activated serpentine minerals can be considered a promising alkaline reagent for technogenic solutions neutralization and purification.

(in Russian, стр.12, fig. 8, tables. 3, ref 19, AdobePDF, AdobePDF 0 Kb)