Due to their unique physical properties, microbubbles have received a lot of attention in waste treatment, aquaculture, and food processing. The demand for high-efficient and low-power consumption microbubble generators has become a challenge today. Swirling flow has been widely proven that it can improve bubble formation. Numerous researchers have developed designs to produce swirl flow and strengthen the turbulence fluid flow. In this study, we present a swirl venturi microbubble generator with a 60° twisted baffle fin on the inlet section. The performance of the swirl venturi microbubble generator was investigated experimentally by bubble diameter, hydraulic power (L_w), and bubble-generating efficiency (η_b) parameters. A microbubble generator was placed in the aquarium with 672 L of water. A high-speed video camera was employed to visualize the flow behavior. The water and gas flow rates varied between 40 – 60 lpm and 0.1 – 0.5 lpm, respectively. The data were analyzed by MATLAB R2022b with the technique image processing method. The results show that most bubbles with 100-300 µm were generated. An increased water flow rate (Q_L) will increase the hydraulic power by 5 Watt, while an increase in gas flow rate (Q_G) will only increase 1 Watt. Bubble-generating efficiency decreases as the water flow rate increases. The lowest bubble-generating efficiency of 0.05% occurs at a Q_L 60 lpm and Q_G of 0.1 lpm. Finally is possible to concluded that the swirl-venturi microbubble generator is an efficient method to produce the microbubbles

Several impoverished nations lack centralized wastewater infrastructure, making water purification difficult. As a result, this work focuses on how to best degrade organic pollutants from wastewater by immobilizing TiO2 on activated carbon peanut shell (ACPNS) using the co-precipitation method in a hydrothermal process under a simulated solar light. The surface morphology and crystallinity of the produced novel hybrid material were analyzed using SEM, TEM, and XRD. The elemental composition and functional group were examined using XRF and FTIR. Using Box-Behnken design (BBD) coupled with response surface models, the photodegradation efficiency of the ACPNS-TiO2 was assessed based on three operation parameters, including the concentration of organic pollutant (10-50ppm), photocatalyst dosage (10-60mg/L), and pH (3-12) at a reaction time of 60 minutes. Using degradation efficiency as a response, the BBD produced an experiment matrix with 17 runs to study the interplay between the three inputs. A reduced quadratic model was developed from the data, and it proved to be excellent at predicting outcomes consistent with the experimental data. The coefficients of determination (R2) for the analysis of variance (ANOVA), which indicated the chosen models for photodegradation efficiency, were 0.98 and 0.97, respectively, and were very significant (p < 0.05). The catalyst dosage was determined as the most critical factor with a substantial oppositional influence on the photodegradation process; however, the interaction effect of pollutant concentration and pH impacted the process favorably with optimum degradation efficiency of 99.92%. The degradation efficiency of the 5^th repeated cycle of the ACPNS-TiO₂ was 74.64%, indicating good reusability of the material. The cost-benefit analysis indicated that the total cost per cubic meter for each treatment activity is 0.8428/m3, implying a low operation and production cost. This work showed that ACPNS-TiO₂ might be effectively used for industrial wastewater treatment reducing the overall cost of pure chemicals.

Medicinal plants are used for treatment of many diseases all around the world. Besides, some medicines are expensive or not readily available.

The increasing prevalence of multidrug resistant strains of pathogen microorganisms constitutes an important and growing threat to the public health due to uncontrolled use of synthetic microbial antibiotics.

Because of the side effects and the resistance that Pathogenic microorganisms build against the common antibiotics; much recent attention has been made to extract the biologically active compounds which are isolated from plants in herbal medicine.

This study has been carried out in order to compare the effectiveness of two medicinal plants Jatropha multifida, Euphorbia hirta and their mixture on the growth inhibition of pathogenic Escherichia coli, the results showed that the ethanolic extracts of the mixture of two plant extracts showed highest inhibition of growth E. coli bacteria. When used independently Euphorbia hirta showed higher inhibition than Jatropha multifida.

The biological wastewater treatment processes utilize excess energy for aeration and pumping, and the generated sludge is associated with severe waste disposal issues. Hence, this study represents a cost-efficient and reliable method for treating wastewater without the requirement of external artificial aeration or additional sludge treatment steps. A down-flow hanging sponge (DHS) system occupied by sponge pieces, i.e., as a biofilm carrier, was established to treat domestic wastewater over 100 days of continuous feed. The DHS reactor was operated at a food-to-micro-organism (F/M) ratio of 0.27 kg COD/kg MLVSS/d, a sludge residence time (SRT) of 89 d, and a fixed hydraulic retention time (HRT) of 1.2 h. The results demonstrated that the removal efficiencies of chemical oxygen demand (COD), total suspended solids (TSS), ammonia (NH₃), and total dissolved solids (TDS) were 78.71±4.23%, 81.67±4.76%, 63.20±3.84%, and 9.95±0.81%, respectively. An additional DHS unit was used as a post-treatment process to improve the effluent quality, giving final concentrations of 38.42±2.21 mg/L for COD, 6.12±0.42 mg/L for TSS, 2.79±0.14 mg/L for NH₃, and 411.31±25.70 mg/L for TDS. The first DHS unit was responsible for the degradation of COD compounds as an organic carbon source, with NH₄⁺-N as the main N-source, for heterotrophic growth. The second DHS was responsible for eliminating a large portion of NH₃, probably due to the occurrence of autotrophic nitrification, converting NH₄⁺ to NO₃⁻. Improving the performance of sequential DHS/DHS units could be attributed to operating the entire system at an F/M ratio of 0.18 kg COD/kg MLVSS/d, SRT of 161 d, and HRT of 2.4 h. The system performance to treat wastewater was successfully predicted by the Monod model, giving kinetic parameters of µ_max= 0.65 1/h and Ks= 12.13 g/L (R² 0.943). Because natural ventilation was used to supply the sponge with oxygen, treating sewage by the dual DHS/DHS system would cost 2.23 US$/m³. It’s suggested that an additional unit, such as membranes, could be used to reduce the remaining TDS concentrations.

A eco-friendly, cost effective, sustainable and green approach were used for the fabrication of silver nanoparticles by using leaf extract of Blumea lacera (Ag@BLE). Silver nanoparticles 9-13 nm sized were characterized by different analytical techniques. Powder X-ray diffraction (PXRD), transmission electron microscopy (TEM) and Fourier-transformed infrared (FT-IR). UV-visible spectra were recorded, which showed a sharp surface plasmonic resonance (SPR) band at 429 nm and confirmed the formation of Ag@BLE. Organic dye methylene blue (MB) is one of the most abundant pollutants in the water environment. In the presence of catalyst Ag@BLE, the absorbance intensity of cationic MB dye was reduced dramatically by Sodium borohydride (NaBH4). The role and efficacy of AgNPs in the catalytic degradation of MB dye were studied, and the reduction rate were found to be 0.01455 min^-1 (0mg Ag@BLE, 21 min), 0.03144 min^-1 (20mg Ag@BLE, 24 min). Synthesized Ag@BLE showed rapid and excellent catalytic reduction of MB dye, and it follow pseudo first order kinetics.

Cerium oxide Nanoparticles) CeNPs are used in chemical mechanical polishing/planarization, corrosion protection, solar cells, fuel oxidation catalysis, automotive exhaust treatment, and sensing. However, their synthesis process increases the likelihood of exposure, potential health effects, and ecological implications; consequently, in regard to this one, it was important to synthesize CeNPs in an environmentally friendly and affordable way to create a better structure. This work discusses the numerous structural properties of CeNPs and is solely concerned with their economical hydrothermal production. To comprehend the shape, FE-SEM was used which shows the granular-like structure. The elastic characteristics of the material like Bulk Modulus was 177GPa, Sher Modulus was 78GPa, Poisson’s ratio was 0.32 and some other properties were also determined by using the FTIR spectrum and also reveal numerous functional groups. The CeO₂ XRD pattern reveals a cubic structure of the space group Fm3m with a density of 6.74gmcm^-3, a volume of 157.81×106pm³, a crystallite size of 18.66nm, a lattice strain of 0.0041, and many other estimated structural characteristics, Rietveld Refinement was also performed for the refined parameters that suggest the high quality of structural parameters like R-factors, wR-factor (𝜒 2) and also designing the crystal structure of cerium oxide nanoparticles. When examining the composition and nature of bonding materials, the structural features are of the utmost significance. It offers a variety of information regarding the subject material's general qualities. Excellent characteristics of nanomaterials include high chemical and physical stability, low density, and a big surface area. Nanomaterials are well-liked options for the creation of brand-new, functioning membranes because of their superior qualities.

Tracers are specialized compounds that are often used in the modern oil and gas industry. Tracing is one of the methods of comprehensive reservoir characterization used along with production rate monitoring of reservoir fluids, 4D seismic, and others for modeling of downhole processes. Tracers are typically used in oil production and reservoir monitoring in the single-well tracer tests and interwell tracer tests with or without partition. The current work proposes innovative use of engineered fluorescent tracers for color tagging of drill cutting at the drill-bit site to determine the depth of cuttings formation.

Previously we reported synthesis and laboratory characterization of novel composite fluorescent tags [1]; at the current work we perform extensive evaluation of operational properties of the obtained materials.

Namely, we examined the effect of tracer’s additives on the rheological characteristics of the oil-based drilling mud, electrical stability, and thixotropic parameters of the drilling emulsion as well as on shear stress, gel strength, plastic viscosity, and yield point. The hot rolling test mimics conditions of mud and formation cuttings circulation in the well and demonstrated the possibility of tracers’ recovery and reuse. It was noted that tracers retain fluorescence and could be detected visually even after 4 months of exposure to the drilling fluid.

Thus, we demonstrated the compatibility of fluorescent tags with oil-based drilling mud and their suitability for downhole applications. Our ongoing work is focused on the development of tracers’ detection system via camera at the shale shaker.

[1] Khmelnitskiy, V.; AlJabri, N.; Solovyeva, V. Preparation and Selection of Best-Performing Fluorescent-Based Tracers for Oil and Gas Downhole Applications. Processes 2022, 10, 1741. https://doi.org/10.3390/pr10091741

Most food liquid products of plant origin are aqueous solutions or suspensions containing dry solutes. In order to reduce the amount of liquid in order to decline transportation and storage costs, minimization of negative chemical, biochemical reactions and microbiological processes, it is recommended to remove part of the water from the products.

Existing industrial methods for obtaining liquid products with a high solids content are characterized by elevated process temperatures, leading to significant losses of volatile aromatic components and to intense corrosion of the equipment. Currently, all liquid products are concentrated by evaporation.

In recent years, there has been a trend towards rising prices for all types of fuel, which increases the cost of steam produced and, ultimately, reduces the profitability of production.

We believe induction fluid heaters are more efficient and economical. Induction heating, unlike other methods, provides bulk and practical inertia of heat release.

Based on the foregoing, in the technology of concentrated products, it is proposed to use an induction steam generator instead of a steam boiler. A cylindrical device replaces the evaporator. Hollow rods are placed inside the cylinder, through which the mass passes. The cylinder, when the winding is turned on, under the influence of an electromagnetic field is heated to a predetermined temperature. The rod heats up, the mass also heats up.

An analysis of the results of laboratory studies shows that the specific energy consumption for evaporation of 1 kg of water is 0.63 kW, and the evaporation rate is 4.5 l/h with a total capacity of 2.5 l.

The effectiveness of the developed induction device has been confirmed by laboratory tests and is recommended for implementation in the production of concentrated food products and other thermal technological processes.

Thus, the introduction of our proposed technical solutions into production will reduce the duration of the production process and capital costs, and save energy resources.

Biochar has been a viable resource in producing functionalized carbonaceous materials beneficial in soil fertility, environmental remediation, and energy recovery. In this study, the influence of Na₂CO₃ in the pyrolytic conversion of green pea peels to biochar was performed to assess biochar's yield and physicochemical characteristics. Experimentations were conducted in batch processes at a constant temperature of 500 ^oC using 0%, 10%, 20% and 30% (W/W) Na₂CO₃ Catalyst by wet impregnation. Characterizations of produced biochar materials have been conducted by bomb calorimetry, SEM, bomb BET, FTIR, and XRD. Accordingly, catalyst incorporation by pre-treatment resulted in a decrease in yield while increasing the porous development. The specific surface area increased from (1.006- 17.7 m²g^-1), and the pore diameter decreased from 173.1 to 9.283 nm. The oxygenated functional groups negatively correlated with the increase in the amount of catalyst whereas the calorific values of the synthesized materials increased from 20.313 kJg^-1 to 25.479kJg^-1 when catalyst impregnation ratio was enhanced from 0% to 30%, indicating that biochar produced from catalyzed processes demonstrate better energy recovery potential.

Representatives of the bacterial species Gordonia alkanivorans are known as degraders of persistent organic pollutants. We studied 11 G. alkanivorans strains (96, 144, 124, 129, 132, 133, 134, 142, 12, 51, GR1) isolated from various natural sources. All studied strains utilized alkanes from C₁₀ to C₂₂ and benzoate; some strains used dibenzothiophene as a sole source of sulfur. Genomes of all strains were sequenced and assembled. The pangenome of G. alkanivorans strains is represented by 4586 genes where 3606 genes (78.6%) formed the core genome.

The DDH value of the strains with the type strain G. alkanivorans NBRC16433 (BACI00000000) is in the range of 78.10-91.00%, indicating some heterogeneity of the species. Based on the results of genome analysis and individual unique genes, strains can be divided into 2 groups within the species. The representatives of the first group (strains 129, 144, 132, 133) are characterized by unique genes of tyrocidine and gramicidin biosynthesis. The representatives of the second group have a greater catabolic potential: genomes of the strains contained 1) operons for the biosynthesis of steroid compounds, 2) additional copies of genes involved in dibenzothiophene catabolism, and 3) genes of aromatic compound catabolic process: Cytochrome P450-pinF2 and Phenol hydroxylase P5. All studied G. alkanivorans strains lack alkB genes in their genomes; therefore, we assume that ability to utilize alkanes in these strains is controlled by the CYP153 genetic system. The CYP153 hydroxylases have at least 99% identity between strains and contain one amino acid substitution each: one hydroxylase has A/T variants at position 239 and the other hydroxylase has A/S variants at position 7 in the first and second strain groups, respectively.

The presented study reveals that the G. alkanivorans strains are metabolically versatile and could be used in bioremediation of soils contaminated with aliphatic and aromatic pollutants.

This work was financially supported by the Russian Science Foundation, grant number 22-74-10082.