Features of the metal distribution in the technogenic and natural waters of the Novoshirokinsky deposit (Eastern Transbaikalia)

To identify the degree of impact of technogenic activity on the main water bodies located in the immediate vicinity of mining production, an analysis of the composition and pH of the water, the chemical components of which are normalized by the Order of the Ministry of Agriculture of the Russian Federation (dated 13.12.2016, No. 552 with amendments), was carried out starting on 10.03.2020.

Soil quality and metal distribution around stone quarries within Abeokuta, Southwest, Nigeria

Quarrying activities are explored to extract a variety of materials deposited underneath the earth surface. These activities however can potentially impact negatively on soil quality and cause elemental pollution. This study assessed soil quality and distribution of metals in soils around four quarrying sites (PAPA, S&D, TCity and Mile 8) within Abeokuta, Ogun State, Nigeria. Thirty six topsoil samples were collected at distances from quarry gates in September 2019 and analyzed using standard methods. Soil quality and metal concentrations were compared with reference and standards and the degrees of soil contamination assessed using relevant indices. Soil quality reduced with distance from the quarry gates. Similarly, metal concentrations had strong and significant (P=0.05) negative relationships with distance and were higher in soil samples compared to the reference. Moderate contaminations for all metals were observed in soils collected close to the quarry gates soils from the results of the contamination factor index (Cf). However, the results of ecological risk index (Ei) showed that the metal loads in soils currently do not pose any ecological risk. Keywords: Quarry, Soil quality, Metal distribution, Soil contamination, Potential ecological risk

Simulation of Combustion and Alkali Metal Distribution in Zhundong High Alkali Coal Boiler Based on Computer Control System

Restricted by Xinjiang’s special geographical location, economic conditions, transportation and other factors, Zhundong coal can’t be sent out on a large scale, which seriously hinders the development of Zhundong coal base. Meanwhile, due to the coal-forming history and Xinjiang’s special natural geographical environment, the alkali metal content in Zhundong coal is generally over 2%, which is much higher than that of power coal in other parts of China. In this paper, based on computer control system, the combustion and alkali metal distribution in Zhundong high alkali coal boiler are simulated, and the morphological distribution characteristics and migration laws of alkali metals such as Na and K in pulverized coal combustion process of high alkali coal, low alkali coal and their two coal samples are deeply studied. Combustion characteristics and heat flow distribution, the simulation results show that the flue gas temperature at the furnace outlet is 895.07°C, and the flue gas temperature near the wall is low, which is helpful to alleviate the slagging and contamination in the furnace.

Linking Bi-Metal Distribution Patterns in Porous Carbon Nitride Fullerene to Its Catalytic Activity toward Gas Adsorption

Immobilization of two single transition metal (TM) atoms on a substrate host opens numerous possibilities for catalyst design. If the substrate contains more than one vacancy site, the combination of TMs along with their distribution patterns becomes a design parameter potentially complementary to the substrate itself and the bi-metal composition. By means of DFT calculations, we modeled three dissimilar bi-metal atoms (Ti, Mn, and Cu) doped into the six porphyrin-like cavities of porous C24N24 fullerene, considering different bi-metal distribution patterns for each binary complex, viz. TixCuz@C24N24, TixMny@C24N24, and MnyCuz@C24N24 (with x, y, z = 0–6). We elucidate whether controlling the distribution of bi-metal atoms into the C24N24 cavities can alter their catalytic activity toward CO2, NO2, H2, and N2 gas capture. Interestingly, Ti2Mn4@C24N24 and Ti2Cu4@C24N24 complexes showed the highest activity and selectively toward gas capture. Our findings provide useful information for further design of novel few-atom carbon-nitride-based catalysts.