Study of the Relationship between Concrete and its Reinforcement Elastic-Plastic Characteristics

The relationship between the elastic-plastic properties of concrete and its ability to resist the external loads and internal stresses effects arising under the influence of aggressive environmental factors has been studied. In concrete, micro-and macrocracks are filled with air and a liquid phase migrates with periodic environmental temperature, therefore, humidity changes. When the structure is compacted by crystalline hydrate neoplasms arising from supersaturated solutions, their surface increases and, correspondingly the part of water hydraulically bound to it also increases which changes its mobility with temperature. This entire system of interphase and single-phase structural bonds and interactions in concrete changes with fluctuations in humidity, cooling, and especially during phase transitions during freezing. The research found that the introduction of hydraulic additives into the binder, which carry a negative charge on their surface, leads to a charge change of the material structure pore space. The penetration kinetics of aggressive environments, adsorption interaction with the cement stone capillaries surface has been studied.

Antibiotic Removal from Aquatic Environment with Activated Carbon Produced from the Pumpkin Seeds

Antibiotics are among the most critical environmental pollutant drug groups. One of the methods used to remove this pollution is adsorption. In this study, activated carbon was produced from the pumpkin seed shell and then modified with KOH. This adsorbent obtained was used in the re-moval of ciprofloxacin from aqueous systems. Fourier Transform-Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), elemental, X-ray Photoelectron Spectroscopy (XPS), Brunauer-Emmett-Teller (BET) and Zeta analyzes were used for the characterization of the ad-sorbent. In particular, the surface area was found to be a very remarkable value of 2730 m2/g. The conditions of the adsorption experiments were optimized based on interaction time, adsorbent amount, pH and temperature. Over 99% success has been achieved in removal works carried out under the most optimized conditions. In addition, it was determined that the Langmuir isotherm is the most suitable model for the adsorption interaction.

Antibiotic Removal from Aquatic Environment with Activated Carbon Produced from the Pumpkin Seeds

Antibiotics are among the most critical environmental pollutant drug groups. One of the methods used to remove this pollution is adsorption. In this study, activated carbon was produced from the pumpkin seed shell and then modified with KOH. This adsorbent obtained was used in the re-moval of ciprofloxacin from aqueous systems. Fourier Transform-Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), elemental, X-ray Photoelectron Spectroscopy (XPS), Brunauer-Emmett-Teller (BET) and Zeta analyzes were used for the characterization of the ad-sorbent. In particular, the surface area was found to be a very remarkable value of 2730 m2/g. The conditions of the adsorption experiments were optimized based on interaction time, adsorbent amount, pH and temperature. Over 99% success has been achieved in removal works carried out under the most optimized conditions. In addition, it was determined that the Langmuir isotherm is the most suitable model for the adsorption interaction.

Water-soluble polymeric particle embedded cryogels: Synthesis, characterisation and adsorption of haemoglobin

Making cryogels, which are among today’s accepted adsorbents, more functional with different methods, has been one of the subjects spent overtime. In this study, water-soluble poly(maleic anhydride-alt-acrylic acid) polymer embedded in poly(2-hydroxyethyl methacrylate) cryogels. Copper ions were then immobilised to this structure, and this polymer was used for adsorption of haemoglobin from aqueous systems. Adsorption interaction was carried out on an electrostatic basis, and approximately 448.62 mg haemoglobin/g polymer adsorption capacity value was obtained. It was found that the same material has managed to maintain its adsorption ability by 90.3% even after the use of it five times in the adsorption/desorption cycle. The adsorption interaction was determined to be appropriate for the Langmuir model by isotherm studies. The change in Gibbs free energy value was calculated as −2.168 kJ/mol.

The Mechanism of Getting New Composite Polymer Materials with Improved Hardness Properties

The main aims and the objectives of the study focused on solving current problems of nanomaterial science of new materials – creating the scientific basis for competitive methods of obtaining and controlling new composite materials having improved strength properties based on carbon-containing polymer matrices with nanotubes stabilized in them. A technology for obtaining experimental samples of nanocompositional polymer material based on polymethylmethacrylate, polybutylmethacrylate, and methacrylic acid doped with carbon nanotubes has been developed, using ultrasonic action and mechanical mixing of the composite mixture to achieve the most uniform distribution of nanotubes in the matrix. To determine the possibility of implementing the mechanism of adsorption interaction of the studied polymer material with the surface of carbon nanotubes, DFT calculations of the interaction of the polymer material component and single-layer carbon nanotubes of various types have been done.

Removal of 17β-estradiol from aqueous systems with hydrophobic microspheres

Sub-microparticles have many applications in different fields today. In this study, it is aimed to develop hydrophobic microparticles as an alternative to existing methods and to determine the 17β-estradiol adsorption performance of this adsorbent to purify the 17β-estradiol hormone which is found as an endocrine disruptor in environmental waters with high capacity and low cost. In this study, l-phenylalanine containing Poly(HEMA-MAPA) microparticles were synthesized by microemulsion polymerization and used as adsorbent. Microparticles were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) methods. The size of the Poly(HEMA-MAPA) microparticles used was measured as 120–200 nm. Specific surface area and elemental analysis studies were also conducted. While the surface area of the particles was found to be a very high value of 1890 m2/g, the amount of incorporation of MAPA into the polymeric structure was calculated as 0.43 mmol/g. Adsorption studies were carried out in the batch system under different ambient conditions (17β-estradiol concentration, temperature, ionic intensity). The adsorption capacity of Poly(HEMA-MAPA) microparticles was calculated to be 98.4 mg/g. Isotherm models for adsorption interaction were investigated deeply, and it was determined that the adsorption mechanism is suitable for Langmuir isotherm.

Antimicrobial magnetic poly(GMA) microparticles: synthesis, characterization and lysozyme immobilization

Micron-sized magnetic particles currently find a wide range of applications in many areas including biotechnology, biochemistry, colloid sciences and medicine. In this study, magnetic poly(glycidyl methacrylate) microparticles were synthesized by providing a polymerization around Fe(II)-Ni(II) magnetic double salt. Adsorption of lysozyme protein from aqueous systems was studied with these particles. Adsorption studies were performed with changing pH values, variable amount of adsorbent, different interaction times and lysozyme amounts. The adsorption capacity of the particles was investigated, and a value of about 95.6 mg lysozyme/g microparticle was obtained. The enzyme activity of the immobilized lysozyme was examined and found to be more stable and reusable compared to the free enzyme. The immobilized enzyme still showed 80% activity after five runs and managed to maintain 78% of its initial activity at the end of 60 days. Besides, in the antimicrobial analysis study for six different microorganisms, the minimum inhibitory concentration value of lysozyme immobilized particles was calculated as 125 μg/mL like free lysozyme. Finally, the adsorption interaction was found to be compatible with the Langmuir isotherm model. Accordingly, it can be said that magnetic poly(GMA) microparticles are suitable materials for lysozyme immobilization and immobilized lysozyme can be used in biotechnological studies.

Natural Zeolites of Eastern Transbaikalia in Technologies for Mining Enterprises Wastewater Treatment

The possibilities of conditioning acidified wastewater from mining enterprises by natural zeolites of deposits in East Transbaikalia were studied. Sorption characteristics of various natural and synthetic zeolites in relation to strontium and cesium radionuclides were determined to evaluate the possibility of their application for the purification of radioactively contaminated technogenic and natural waters. The ability of natural zeolites to selectively adsorb the heavy metal ions was investigated. An experimental study was made on the possibility of neutralizing acidic media with zeolites. The kinetic dependencies were obtained to evaluate the ion exchange rate on the natural zeolites. The impact of exchanging cations and the defining mineral’s structure on the exchange rate was studied. The instantaneous adsorption interaction rate values were determined. The possibility of 90Sr and Ca2+ ions sorption from the simulated solutions of industrial wastewater was investigated.