In this work, chitosan-TiO2 nanocomposites (NСs CS-TiO2) were developed for the photocatalytic degradation of some representatives of polycyclic aromatic hydrocarbons (PAHs). TiO2 nanoparticles (NPs) were synthesized by laser ablation method and their sizes were determined by dynamic laser light scattering (DLLS). Anthracene and pyrene in micellar solution were used as representatives of PAHs. The effect of TiO2 in the composition of prepared nanocomposites on the photodegradation of PAHs in model environments under UV irradiation was studied. The method of solid-phase luminescence (SPL) was used to estimate the decrease in PAHs concentrations. Based on the results of the studies carried out, pseudo-first order photodegradation kinetics were plotted. The efficiency of using the nanocomposites for the photocatalytic degradation of anthracene and pyrene was proved.

The preparation method of modified chitosan films for adsorption of pyrene from solution is described. Solid-phase luminescence of samples was studied, degree of extraction and index of polarity of microenvironment of pyrene molecules was determined. It has been proven possible to carry out luminescent analysis of substances for pyrene content using made films. The observed results demonstrate an ability for the using method of solid-phase luminescence (SPL) to increase the range of optical transparency and avoid pre-extraction and concentration of the test samples.

In this study, samples of fine-grained concrete with the additive T1O2 microparticles were made. The photocatalytic properties of TiO2 for the decomposition of anthracene in solutions under UV irradiation were studied. To evaluate the efficiency of photodegradation, the method of luminescence analysis was used. For improving the quality of the analyzed solutions, model surfaces were made based on chitosan with the addition of TiO2. According to the results of the experiments, it was found that the degree of photodegradation of anthracene in solutions using solid chitosan-TiO2 matrices reaches 74% after 60 minutes under UV irradiation. The conducted studies confirm the feasibility of using chitosan-TiO2 matrices as model surfaces for studying the photocatalytic properties of TiO2 for the oxidation of anthracene.

In this work, samples of fine-grained concrete were made with the addition of TiO2 powder in a range of 1-3 wt% relative to the cement. The photocatalytic properties of photocatalytic concrete for the degradation of pyrene in solutions of sodium dioctyl sulfosuccinate under UV irradiation were investigated. To evaluate the efficiency of photodegradation, the method of luminescence analysis was used. It was found that the degree of degradation of pyrene in solutions using photocatalytic concrete reaches 25% after 120 minutes under UV irradiation. The compressive strength of the manufactured samples was also studied. A decrease in strength of no more than 24% was registered. To prevent the negative effect of the TiO2 additive, a plasticizer was used. In this case, the compressive strength increased from 19 to 31% relative to the samples without plasticizer.

Introduction. The purpose of this work is to study the thermally modified peat additive, the use of which is scientifically justified in the works of professor N.O. Kopanitsa and her colleagues. This additive is extracted from the raw materials from the Kaliningrad region, and the authors focus on its effect on the consistency, moisture-retaining capacity of the mix, and the strength characteristics of fine-grained concrete. Materials and methods. The additive was made from lowland peat extracted from the Glushkovo quarry in the Kaliningrad region. Raw materials were subjected to thermal treatment with limited access of oxygen. Results. The authors have proven an increase in the consistency and water-retaining capacity of mixes that have 4 and 8 % additive. On the 21 day, an 9 % increase in the flexural strength of concrete specimens with the 4 and 8 % additive was registered in comparison with the benchmark specimen (5.5 MPa for the benchmark mix and 6 MPa for the 4 and 8 % additive); an increase in compression strength reached 23 % when the 8 % additive was used (40.7 and 50.2 MPa for the benchmark mix and the one that contains the 8 % additive, respectively). Conclusions. The presented results of the research show a strong potential for the improvement of physical-mechanical properties of concretes by using thermally modified peat additives made from the local raw materials extracted in the Kali­ningrad region.