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Date submitted2023-03-20
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Date accepted2023-09-20
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Date published2023-10-27
Experimental simulation of a system of swamp biogeocenoses to improve the efficiency of quarry water treatment
Mining activities were producing large quantities of wastewater contaminated with nitrogen compounds and metals. With insufficient treatment, these pollutants are released into the environment and have a toxic effect on living organisms. Constructed wetlands are now widely adopted as wastewater treatment systems because of the combination of physical, chemical and biological processes for the removal of contaminants. In this study, an experimental system was modeled to improve the efficiency of the quarry wastewater treatment of a mining enterprise by sharing the higher aquatic vegetation: broad-leaved cattail (Typha latifolia L.), common water-plantain (Alisma plantago-aquatica L.), jointed rush (Juncus articulatus L.) and lower aquatic vegetation (Chlorella sp.). Concentrations of nitrogen compounds and metal were analyzed both in the model and in the treated solution of quarry wastewater for calculation of treatment efficiency. Concentrations of the pollutants in the tissues of the higher aquatic vegetation were analyzed to assess the accumulation capacity and efficiency of translocation of the pollutants. The results of the experimental study showed the practical applicability of the constructed integrated treatment system to reduce the concentration of pollutants in quarry wastewater, as well as increasing the efficiency of treatment by introducing lower aquatic vegetation into the system
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Date submitted2023-04-29
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Date accepted2023-10-11
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Date published2023-10-27
Pink-violet diamonds from the Lomonosov mine: morphology, spectroscopy, nature of colour
The article presents the results of the first comprehensive study of mineralogical and spectroscopic (IR, PL, EPR) characteristics of diamonds from the Lomonosov mine (Arkhangelskaya pipe) with a unique pink, pink-violet colour. It is shown that all crystals belong to the IaA type, with a total nitrogen content in the range of 500-1500 ppm, with a low degree of aggregation. The colour is heterogeneous, concentrated in narrow twin layers. It is presumably caused by the previously described M2 centres. The colour shade is affected by the content of P1 paramagnetic centres (C-defect). A positive correlation is observed between the colour saturation and the intensity of W7 paramagnetic centres. A convergent model of the formation of pink diamonds is assumed, according to which the determining factors are the ratio and concentration of structural impurities in the diamond, its thermal history, and conditions of plastic deformation, and not the origin of the diamond and the petrochemical properties of its host rocks.
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Date submitted2022-11-29
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Date accepted2023-03-02
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Date published2023-10-27
New data on the composition of growth medium of fibrous diamonds from the placers of the Western Urals
This article presents the results of studying microinclusions of fluids/melts in diamonds from the placers of the Krasnovishersky District (western slope of the Middle/Northern Urals), which make it possible to establish the evolution of diamond-forming media in the subcontinental lithospheric mantle of the eastern margin of the East European craton. Impurity composition of the studied crystals reveals three different types of diamonds, the formation of which was associated with separated metasomatic events. Microinclusions in B-type diamonds containing A and B nitrogen defects reflect an older metasomatic stage characterized by the leading role of silicic and low-Mg carbonatitic fluids/melts. The second stage is associated with the growth of A-type diamonds containing nitrogen exclusively in the form of A-centers. At this stage, the formation of diamonds was related with low-Mg carbonatitic media, more enriched in MgO, CaO, CO2, and Na2O compared to B-type diamonds. The third stage probably preceded the eruption of the transporting mantle melt and led to the formation of C-type diamond containing A and C nitrogen defect centers and microinclusions of silicic to low-Mg carbonatitic composition. The recorded trend in the evolution of diamond-forming fluids/melts is directed towards more carbonatitic compositions. Fluids/melts are probably sourced from eclogitic and pyroxenitic mantle substrates.
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Date submitted2022-04-13
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Date accepted2022-06-15
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Date published2022-07-26
Thermal history of diamond from Arkhangelskaya and Karpinsky-I kimberlite pipes
This work studies and compares the main morphological, structural, and mineralogical features of 350 diamond crystals from the Karpinsky-I and 300 crystals of the Arkhangelskaya kimberlite pipes. The share of crystals of octahedral habit together with individual crystals of transitional forms with sheaf-like and splintery striation is higher in the Arkhangelskaya pipe and makes 15 %. The share of cuboids and tetrahexahedroids is higher in the Karpinsky-I pipe and stands at 14 %. The share of dodecahedroids in the Arkhangelskaya and Karpinsky-I pipes are 60 % and 50 %, respectively. The indicator role of the nitrogen-vacancy N3 center active in absorption and luminescence is shown. Crystals with the N3 absorption system have predominantly octahedral habit or dissolution forms derived from the octahedra. Their thermal history is the most complex. Absorption bands of the lowest-temperature hydrogen-containing defects (3050, 3144, 3154, 3188, 3310 cm −1 , 1388, 1407, 1432, 1456, 1465, 1503, 1551, 1563 cm −1 ), are typical for crystals without N3 system, where in the absorption spectra nitrogen is in the form of low-temperature A and C defects. The above mentioned bands are registered in the spectra of 16 % and 42 % of crystals from the Arkhangelskaya and Karpinsky-I pipes, respectively. The diamond of the studied deposits is unique in the minimum temperature (duration) of natural annealing. Based on a set of features, three populations of crystals were distinguished, differing in growth conditions, post-growth, and thermal histories. The established regularities prove the multi-stage formation of diamond deposits in the north of the East European Platform and significant differences from the diamonds of the Western Cisurals. The results suggest the possibility of the existence of primary deposits dominated by diamonds from one of the identified populations.
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Date submitted2015-08-17
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Date accepted2015-10-25
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Date published2016-04-22
Ecological aspects of vehicle tunnels ventilation in the conditions of megalopolises
- Authors:
- S. G. Gendler
The characteristic of Russia and foreign vehicle tunnels are provided in paper and advantages of their placement in the conditions of the city are noted. It is shown that one of the main factors defining negative impact on environment in the period of tunnels driving is mine equipment, and at operation – vehicles. The analysis of essential differences of features of pollution of atmospheric air at construction of tunnels from its pollution at construction of buildings on a surface is given. The examples illustrating levels of negative impact of the upcast ventilation shaft airflow on atmospheric air are given and the ventilation schemes reducing this influence are offered. It is shown that during operation of road tunnels of pollution of the air environment can extend on considerable distances from tunnel portals. Numerical calculations of concentration of carbon oxides and nitrogen during removal of the upcast ventilation shaft airflow through portals and through the mines built near them are executed. Technical solutions on purifications of tunnel air by means of electrostatic filters are described.
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Date submitted2008-10-02
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Date accepted2008-12-18
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Date published2009-12-11
New data on infrared spectroscopy of diamonds from industrial deposits of Yakutia
- Authors:
- I. N. Bogush
- S. I. Mityukhin
- E. A. Vasiliev
Results of investigation of large diamond samples from main primary and some placer deposits of Yakutia by FTIR is given. Comparison of various characteristics indicates that maximal difference for samples of diamonds from different sources and minimal diversity for different samples from one source have average values of absorption coefficient and maximum positions of B2 absorption band. The revealed parameters are proposed to be used during comparative analysis of diamonds of different kimberlite pipes, determination of the initial source of placer diamonds, forecasting of new sources.