System solutions for technological problems. Рубрика в журнале - Nanotechnologies in Construction: A Scientific Internet-Journal
Статья научная
Introduction. Activated sludge is one of thepulp-and-paper industry waste types. Within the framework of the rational natural resources’ utilizationand the waste recycling, due to its composition, activated sludge could be subjected to certain technological solutions for the production of nanofertilizers, since it has been previously the basis for making of various soils and biological products. However,occasionally the composition of activated sludge may contain different toxic compounds, heavy metals, and their impact on soil fertility and plants vital state is profound. Thus, the purpose of our research is to study the effect of the activated sludge introductionas a basis for nanofertilizers on the heavy metals contentin podzolic soils of various granulometric composition in agricultural exploitation. Methods and materials. Research was conducted under the conditions of dummy experimentin vegetation vessels. We have used podzolic soils of various granulometric composition (clayey, loamy, sandy) and pulp-and-paper industry waste – activated sludge in concentrations of 1; 2.5; 5 and 10% of the dried soil weight. Determination of the heavy metals gross content has been carried out by the atomic absorption method with measurement on the AA-7000 spectrophotometer (Shimadzu, Japan); mobile fraction of heavy metalsdetermination (подвижныеформы) – utilizing acetate-ammonium buffer solution by inductively coupled plasma mass spectrometry methodology. Results and discussion. The paper presents the results of the research on mobileand gross forms of heavy metals in podzolic soil of various granulometric composition when applying activated sludge as the basis of organic nanofertilizer under the dummyexperiment. Conclusion. It was shown that the content of mobile and gross forms of the studied metals (Fe, Mn, Cu, Zn, Ti, Al, Ni, Co, Cr, Cd and Mo) were within the health-based exposure limits, with the exception of Cd gross form, where the maximum excess was 2.5 MAC (maximum allowable concentration).
Бесплатно
Статья научная
Introduction. In the modern socio-economic and geopolitical development of Russia, the development of industry comes to the fore. Among the many industries, ammonia stations play the most important role. The main regularities of the process of pumping and preparing water. The process consists of six stages, this article discusses the automation of stages 1 and 2: for water treatment and pumping it out with pumps H1 and H2 from the tank P2. Products in the form of purified water are the most important criteria for subsequent production at an ammonia plant, therefore, increased requirements are imposed on the quality of finished products, including the quality of purification of the water used with the help of nanofilters. The required quality cannot be achieved without control the process in an automated mode. Development of a neural network. To control the converters frequency values during the preparation and pumping of water, an artificial neural network must be used. Its development was carried out in the Matlab environment in the Neural Network Toolbox package, input and output data were defined for this, data processing and preparation were performed, as well as the choice of the type and architecture of the neural network. The architecture of the Layer Recurrent neural network, the process of its construction and training in Matlab is described. Testing of neural networks. During testing of the Layer Recurrent network for the degree of their training, the smallest error was obtained for 30 neurons in the hidden layer. The proximity to the set values indicates the applicability of the network for controlling the parameters of frequency converters. Development of the neural network controller model in the Simulink package. The simulation of the control system in the Simulink package using a neural network controller with the Layer Recurrent architecture is performed. Checking the frequencies of the frequency converters H1 and H2 in Simulink for the level parameters in the tanks and in the tank LT1_вх, LT2_вх, LT3_вх showed that the object model works correctly, thus, the simulation of the neural network showed that the training was successful. Conclusion. As a result of the conducted research, an artificial neural network was developed to control the process of preparing and pumping water in the Matlab environment and a simulation of a neural network in the Simulink package.
Бесплатно
Статья научная
Introduction. The economic activity of a person entails environmental, economic and social damage to the environment. The production of goods or services is associated with the consumption of natural resources and emissions that negatively affect the ecological state. Currently, there is an acute problem of the negative impact of man on the natural environment and is the main source of deterioration in the health of living beings. In modern conditions, chemical safety is one of the priority tasks of socio-economic development. To protect the environment, it is important to take appropriate measures and develop appropriate mechanisms to promote sustainable development. For this purpose, an assessment of the environmental and economic damage from human activities is required. Materials and methods. The work employs the method for determining the prevented environmental damage, approved by the Chairman of the State Committee of the Russian Federation for Environmental Protection, to perform ecological and economic assessment of the environmental impact of new environmentally friendly biodegradable additives for polyvinyl chloride based on adipic acid. Results and discussion. Polymeric materials, as the most popular and widespread, make a significant contribution to the deterioration of the environmental situation. In this regard, the main values of the prevented environmental damage from soil degradation were calculated when using new environmentally friendly additives for PVC based on adipic acid. Conclusion. The introduction of the developed additives into the composition of the developed additives provides economic and environmental efficiency in order to accelerate the biodegradation of polymer composite materials, protects against chemical pollution by hazardous toxic compounds and helps prevent soil degradation.
Бесплатно
Статья научная
Introduction. Recent years have seen a pressing need to dispose of municipal solid waste due to rapid urbanization. The municipal solid waste incineration fly ash (MSWIFA) produced from solid waste incineration power plant exhibits pozzolanic properties and poses concern of toxicity leaching when used directly as building materials. This paper presents an alkali-activation method to produce sustainable alkali-activated MSWIFA materials (AAFMs) with various MSWIFA dosages and investigate the corresponding fabrication and performance. Materials and Methods. Composited alkali activators activate the MSWIFA with constant alkalinity of 5% and the molar ratio of Si/Na = 0.86. The resulting geopolymers' bulk densities, mineral composites, morphology, and compression strength are thoroughly examined. Results and discussions. Results show that the use of MSWIFA may lead to more loose structures because the bubbles are generated from metallic aluminum and alkali activators. Additionally, the production of multiple crystals also accounts for increasing porosity. The generated multi-crystals such as Sylvite, Halite, Hydrocalumite, Calcium Hydroxide, and Ettringite are further detected from the morphology and mineral analysis. Furthermore, compression tests and toxicity characteristic leaching procedures (TCLP) are conducted to investigate the mechanical performance and heavy metals solidification performance of AAFMs, with an optimal compression strength of 19.99MPa at 28 days for AAFM-10 while toxicity leaching is subject to regularity limits. Conclusions. This study shows that great potential of using the alkali-activation method to recycle hazardous municipal solid fly ash into construction materials with both ecological safety and high performance.
Бесплатно
Статья научная
Physico-chemical processes of structure formation in nanocomposite building materials are associated with transformations of binding matrices and reinforcing components. The efficiency of building composites in the designed structures depends on the accurate choice of the source components: nanobinders, fillers (aggregates) and manufacturing technology. Increased corrosion resistance of building materials is provided by optimal selection of nanobinders and fillers, by increased density and treatment of the structure surface with protective coatings. The manufacturing feasibilities for nanocomposites based on various raw materials, nanobinders (gypsum, cement, bitumen, polymer, etc.), and inclusion of various dispersed phases (nanofillers, natural and technogenic aggregates) expand the variety of building composite materials. The synergistic dynamism of the occurrence of geometrical regularity of nanostructures during the structure formation of binders correctly demonstrates the fractal concept. Fractal nanostructures of binders with a rough surface are formed according to mechanism of diffusion-limited aggregation.
Бесплатно
