By current study determined dependence between changing of the average capacitance of the destroyed electrodes of chemical current sources, surface geometry and chemical composition of electrodes surface. In case of the minimum destruction of the surface of the electrode, the maximum value of the average capacity is achieved with the ratio Zn: Mn = 2: 1. The minimum capacity was been at a maximum concentration of manganese on the surface (Zn: Mn = 1: 3) and the maximum degree of destruction. That is, the destruction of the surface of the electrodes leads to a change in the ratio of Zinc and Manganese and with strong surface destruction, the number of Manganese increases significantly. The using of the second frequency-dependent parameter (capacitance dispersion) as a lumped parameter was allowed the application of the principles of electric current commutation for register the layered change in the electric characteristics of the destroyed electrodes. Due to that mathematical technique was obtained a visual picture of the quantitative and qualitative changes on the destroyed surfaces. The general view of the received diagrams repeated the contours of the SEM microphoto images of the same surfaces. There is a presence of sites with the local concentrated deviations from the total distribution of the capacitance in the specific frequency range in case of deep damage in the diagrams. Thus, these diagrams (EIS images) give a clear picture of the electrodes surface of and can be used to evaluate the type of surface damage and the degree of destruction of the electrodes of chemical current sources.
The review analyzes the physical and chemical properties of modified natural and artificial layered aluminosilicates, which form the basis for the emergence of thermoelectric properties in materials based on them. It represented the main methods of modification and analysis of structural and thermoelectric properties of these materials. Chemical modification of layered aluminosilicates is carried out by the reaction of solid aluminosilicate with concentrated aqueous solutions of metal hydroxides of groups I and II, their silicates, or phosphoric acid. The products of such interaction are called geopolymer. This name used to describe the reaction of the transformation of amorphous aluminosilicate into crystalline products during the interaction the solid product with concentrated alkali solutions of metals from the groups I and II, or the formation of composites and gel systems. The change in particle size, acidity of the media and impurity exchangeable cations in layered aluminosilicates significantly affects its acid-base and catalytic properties in aqueous solutions. The use of aqueous solutions increases the effect of hydrolytic processes on the number of hydroxide groups in the composition of the mineral, which are responsible for the adsorption properties and create the possibility of oxidative-destructive catalysis with the participation of the mineral. The ion-exchange capacity of layered aluminosilicates depends on the degree of their dispersion. The increasing degree of the Perdispersion level increases the ion-exchange capacity of the material. It is also possible to modify layered aluminosilicates with phosphoric acid, which can form polymers. Using phosphoric acid allows high temperatures over 900 C to change the electrical properties of minerals. The priority directions for strengthening the properties of heat-to-electricity conversion through the development of composite materials based on layered aluminosilicates using metal nanoparticles, silicon carbide, carbon, graphene, graphene-like materials, and metal oxides embedded in the aluminosilicate matrix have been established.
The analysis of the general physical and chemical indicators and the maintenance of heavy metals of sewage of a bioenergy complex is carried out. It is established that the sedimentation rate of suspended particles in wastewater depends on the location of filtration fields with wastewater from the source of contamination. At the source, there is a maximum excess of the number of suspended particles with a minimum deposition rate. In all wastewater samples, the indicators of chemical and biological oxygen consumption exceeded the permissible standards by three orders of magnitude for reservoirs for recreational water use and those located within the settlements. Thus, this water cannot be discharged into any natural water basin and requires additional purification from organic matter. Also for this water, the use of biological treatment methods without additional chemicals is ineffective. The presence of a complex of macro- and microelements in wastewater in combination with a high content of organic matter (humus and sulfonic acids) may be the basis for their use as raw material for fertilizer production.
This work studied the impact of graphene content and heat treatment on the structural changes and electrical parameters of graphite/N-doped graphene mixtures. Using photoelectron spectroscopy the appearance of two types of carbon-containing phases was detected in the visible range of the N-doped graphene samples synthesized from liquid nitrogen. The following features of the samples were shown: one typical structure of graphene (sp2C–sp2C), two atypical structures (sp3C–N and the C–O bond), and graphene components modified with nitrogen (pyridine–N, pyrrole–N, graphite–N and oxidized N–O). The dependence between the ratio of components in graphite–graphene mixtures and their electrochemical properties was found. The effect of graphite content and heat treatment on the change in the type of conductivity in a graphite–graphene mixture was determined by comparison of resistance and capacitance distribution in the frequency range of 100–900 Hz. The change of the graphite concentration in the graphene–graphite mixture allows governing the type of doping and electrical parameters of the mixtures.
A study of the accumulation of metal ions in the sludge of the bioenergy complex after burning the plant's raw materials was carried out. The value of the content of toxic metals (cadmium, lead, and mercury) is less than an order of magnitude than the MPC for soils. The presence of a complex of trace elements, iron, calcium, magnesium, and sodium in sludge makes them attractive for use as raw materials for production of organic-mineral fertilizers for the cultivation of a sufficiently wide range of agricultural and ornamental crops. It was studied that distribution of heavy metals in sludge of the filtration fields in different depths : 1 – from the surface (1–5 cm), 2 – from the middle (~500 cm) and 3 – from a depth > 1500 cm. The distribution of metal's ions accumulation established that the maximum content of cadmium and nickel observed in the surface layer of silt, lead in the middle layer, and manganese in the deep (more than 1500 m) layer. Such distribution of heavy metals shows, that the maximum concentration of cadmium and lead takes place in the surface layer of silt, lead in the middle layer , and manganese in the deep (more than 1500 m) layer. Thus, the deep layer is the safest to use as a raw material in production of fertilizers. But the presence of cadmium and lead, which have cumulative properties, in all layers of sludge is a risk factor for using sludge as fertilizers for crops that will be used for food purposes but can be use for growing technical crops and ornamental plants. Also, the presence of aluminum and titanium in the composition of the sludge requires a more detailed study. The final decision is possible only after conducting field tests, with subsequent analytical control of products and soil after harvesting.
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