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  • Open access
  • 19 Reads
Preparation and catalytic study of Mn-NaX, Cu-NaX and Ag-/AgNPs-NaX zeolites

Zeolites are crystalline aluminosilicates with uniform pores, cavities and channels and find application in various industries due to their catalytic, sorption and ion exchange properties [1]. The hydrothermal synthesis is perspective method for obtaining of zeolites [2].

FAU-type zeolite NaX was successfully obtained using hydrothermal synthesis at 90oC for 6 hours. The Mn and Cu ion exchanged NaX zeolites were obtained using 0.4M MnCl2 and 0.1M CuCl2 solutions. After the ion exchange the zeolite powders were thermally treated at 300oC. As well as Ag ion exchanged zeolite NaX and zeolite impregnated with two types of Ag nanoparticles dispersions – citrate surface stabilized (citAg) and polymer stabilized (pAg) nanoparticles. Silver nanoparticles were synthesized by electrochemical reduction method. The changes in phase and chemical composition and structure of obtained zeolite powders before and after ion exchange or impregnation were investigated by Powder X-ray analysis, Infrared spectroscopy and X-ray fluorescence (XRF) analysis. The XRF results determined that NaX zeolite; Mn, Cu, Ag ion exchanged and impregnated with two types Ag nanoparticles zeolite have the elemental composition: Na (16.49; 2.24; 2.48; 11.37; 12.44; 15.54), Al (29.22; 24.80; 23.46; 23.67; 29.08; 28.99), Si (53.91; 40.18; 33.44; 38.04; 57.51; 54.66), Mn (32.67), Cu (34.13), Ag (26.85; 0.53; 0.53) mass%, respectively. The catalytic ability of the prepared Mn, Cu-exchanged NaX and Ag nanoparticles impregnated zeolites were tested in the reaction of ozone decomposition. The results show that Mn, Cu-exchanged NaX and impregnated with Ag demonstrated catalytic ability towards ozone decomposition in comparison with pure zeolite (non-catalytic activity).


[1] S. Chandrasekhar, P.N. Pramada, Sintering behaviour of ammonium exchanged low silica zeolites synthesised by two different routes, Ceramics International 27 (3) (2001) 351-361.

[2] C.S. Cundy, P.A. Cox, The Hydrothermal Synthesis of Zeolites: History and Development from the Earliest Days to the Present Time, Chem. Rev., 103 (2003) 663-701.

  • Open access
  • 21 Reads
Macrophytic Vegetation of River Ethiope at Umuaja, Ukwani Local Government Area of Delta State, Nigeria

This abstract presents an overview of aquatic macrophytes and their importance for the structure and function of aquatic ecosystems. It also discusses the effect of water quality and nutrient enrichment on macrophyte distribution, and the development of survey and monitoring techniques for characterizing waterside habitats. Finally, it highlights the need for detailed data for detecting change at individual sites. Physicochemical parameters are major factors when considering the quality of water samples to the presence of macrophytes in an aquatic ecosystem. A study carried out from January to March in 2019 shows that the mean value of water temperature was the highest in February with a mean value of 26.5oC; PH, alkalinity, sulfate (SO42-) and nitrate (NO3-) were the highest in January while conductivity, total hardness of water, magnesium, biological oxygen demand (BOD) and phosphate were the highest in March. Moreover, water was 100% transparent during the whole study period. Twelve (12) macrophytes belonging to ten (10) families were encountered. The most abundant macrophytes encountered were the species Bumbusa vulgaris (Poaceae family). A single emergent macrophyte Ipomoea aquatic (Convolvulaceae family) was encountered. Free-floating and submerged macrophytes were absent due to the high flow rate of the river. It was observed that the physiocochemical parameters of River Ethiope fall under the normal range of good quality water supporting Macrophytic vegetation.

  • Open access
  • 33 Reads
Developing a relationship between ore feed and flotation performance.

Although topical research, the study of floatation systems is still complex. Numerous physical and chemical factors are involved in the recovery of valuable minerals by flotation. While the chemistry of the system can be manipulated to improve the performance, the system is limited by the mineralogy of the incoming ore as well as the quality of the process water, which in most cases is not controlled. Stringent water restrictions and regulations have made it a necessity for mines to find alternative sources of water that meet the water demands required for operations. Hence, recycling of on-site process water is becoming a norm for many operations, this recycling changes process water quality over time and influences floatation performance.

This study seeks to understand the impact of ore feed grade on froth stability, entrainment and flotation performance under varying water qualities. The development of a relationship through which the flotation performance may be predicted if the ore feed grade and water quality are known. The study will consider predefined synthetic ore types and water qualities to measure froth stability, floatation performance and entrainment through froth column studies, batch floatation and UCT's high depressant method, respectively.

  • Open access
  • 36 Reads
Sustainable textiles from unconventional biomaterials - cactus-based
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The current environmental situation on our planet shows that a moderate use of resources is necessary. Petroleum-based resources are used in the production of products and luxury goods, and the recycling of products at the end of their life cycle is not environmentally friendly, and the depletion of resources leads to these problems. Strengthening and using the sense of responsibility for the future can be an effective tool to promote environmental awareness and intergenerational environmental behavior. In this case, many new ideas and business models are emerging that use bio-based sustainable materials for various products. A stronger sense of responsibility for the future can be an effective tool for promoting environmental awareness and intergenerational action. In this case, many new companies using bio-based materials for various products are emerging. In fact, it has become a kind of fashion trend to live vegan or wear vegan goods and clothes. In this case, a vegan alternative to leather has been sought, as many people would like to avoid using animal leather of any kind in the future. Various studies showed that vegan leather from cacti or mushrooms is particularly suitable, as it is very close to real leather and covers its properties. Polyurethane (PU) leather made from plastic or animal leather is no longer necessary. The fashion industry causes massive negative impacts on the environment. It is the second largest polluter in the world, of which leather is a major contributor. There are more than 5000 species of cacti, with most species found in the Americas. They are widely distributed in the arid regions of Mexico (e.g., Chihuahuan Desert), Brazil (e.g., Caatinga region), and Argentina (e.g., Jujuy Province). In general, there are 3 different types of cactus that can be processed into cactus leather - Nopal cactus, Sahuaro cactus and Bisnaga cactus. Cactus leather has many positive characteristics that may surprise the reader, because the material quality is very close to that of real leather. For example, some positive environmental aspects play a big role here. When the cactus is harvested, the actual plant/root is not damaged, so it can continue to grow and continue to process carbon dioxide. In addition, cactus leather is plastic-free and the processing does not harm the environment. In addition, cacti do not need so much water, there is no need to water. . Cactus leather is a very good alternative product because it covers the functions of animal leather in most parts. It remains to be seen if it can completely replace real leather. With further and improved research in the field of cactus leather, it could well be possible to do away with animal leather altogether soon and vegan alternatives will be available.
This paper discusses sustainable materials based on cactus species that can replace leather products, for example, and explores the development of bio-based textiles in the near future.

  • Open access
  • 32 Reads
Optimization study for the desorption of arsenic and regeneration performance on magnetic carbon xerogels for environmental sustainability

The presence of arsenic in the aquatic environment has significantly generated arsenic exposure causing various health problems. The adsorption process for removing arsenic from water and wastewater treatment is considered an effective technology. However, various influencing factors on the desorption and reuse of adsorbent are necessary to investigate for an economically and environmentally acceptable approach. In this study, magnetic carbon xerogels was synthesized by direct sonication for loading magnetite nanoparticles in sol-gel polycondensation onto resorcinol-formaldehyde gels, carbonized the organic gel, and induced surface modification by using hydrogen peroxide. Magnetic carbon xerogels were characterized by various techniques such as SEM, EDX, TEM, XRD, and FTIR. Dispersed particles of magnetite nanocrystals ranging around 15-20 nm composed on the carbon xerogels in crosslinking nanostructure. In addition, the pyrolysis treatment at 850 °C developed the texture of the material, improving the porosity and decreasing the size of the particles. The optimization of the desorption capacity was carried out with a Response Surface Methodology determining the most significant quantitative factors, which was the adsorbent dose. The arsenic adsorption data were described by the Elovich and Power equations of the kinetic model. Magnetite nanoparticles, organic gel pyrolysis process and surface modification by use of H2O2 had a considerable impact on the morphology and surface chemistry resulting properties of magnetic carbon xerogels and significantly influenced the adsorption capacity of arsenic. Moreover, the regeneration capacity of magnetic carbon xerogels was evaluated and determined in 4 sequential adsorption-desorption cycles, indicating the possibility of reusing the adsorbent and reducing the possible environmental impact.

  • Open access
  • 24 Reads
Rational use of whey in food production.

The processing of milk into milk-protein concentrates – cheese, cottage cheese, casein, is inevitably associated with the production of a by-product of sweet or sour whey. The global production of whey is estimated at about 180 to 190 tons/year. Of this amount, only 50% is recycled. In the Russian Federation, only 30-40% of the total amount of whey is processed, which is irrational, since it can be used as a valuable nutrient.
The purpose of this study was to evaluate the protein potential of whey, which remains after the production of cottage cheese at dairy enterprises.
To study the protein content, Tommoloko brand whey was taken, then heated to a temperature of 85-95 ℃, having previously measured the pH of the medium, after which 1 ml of 70% NaOH solution was gradually introduced with a dispenser, bringing the pH of the medium to an interval of 6.5 – 7. The precipitate obtained after the experiment was filtered under pressure for a more complete collecting material. The resulting precipitate was dried on the AK5-4.0 brand freeze-drying. The resulting dry precipitate is a white, crumbly mass with a slightly milky odor.
After weighing the dry protein, it was revealed that manufacturers lose more than 19 g of protein per 1 liter of whey, which indicates a significantly low cost of this product today.
Thus, the numerous functional and nutritional properties of whey proteins and products based on them make it possible to ensure the use of whey derivatives in wide branches of the food and agricultural industry.

  • Open access
  • 66 Reads
Developing biopolymer based edible films with improved antimicrobial properties.
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The market of food packaging industry is predicted to be worth $423.27 billion by 2025. Biopolymer based edible and biodegradable food packaging films is gaining more importance recently due to the toxic effects of synthetic polymers on environment and health hazards to humans and other animal life.
The focus of present study is to develop polysaccharide (pectin) and protein (gluten) composite films. Castor oil was used as hydrophobic agent to improve moisture barrier properties. A statistical 22 (two-level two-factor) factorial design of experiments was adopted to develop and study the properties of the films. The percent of gluten (15% &30% w/w) and castor oil (5% & 15% w/w) with respect to the amount of pectin were chosen as the two factors. All the other process parameters such as concentration of film forming solution (5% w/v), pH (=3) of solution, temperature (40 ℃) and relative humidity (60%) of drying, were kept constant based on our previous optimization studies. For comparison, a base level films, pure pectin, pectin and gluten without castor oil films were also developed.

All the films were analyzed for sensory, moisture barrier, mechanical, surface hydrophobicity, morphological and biodegradability properties. All films were thin (~ 0.125±0.004) and transparent (ΔΕ= 11 to 25). Films made from 30% w/w gluten and 15% w/w castor oil showed best moisture barrier, and tensile properties. Addition of castor oil improves the hydrophobicity capacity of the films compared to control pectin and gluten films. The moisture permeability reduced by 2 times and the elongation at break decreased by 5 times compared to control pectin films. The Analysis of variance (ANOVA) studies infer that the effect of amount of castor oil (P<0.05) and the combined effect of amount of castor oil and gluten (p<0.05) is significant on the properties of the films.

  • Open access
  • 34 Reads
A new hydrophobic deep eutectic solvent based on D2EHPA and TOPO: synthesis and properties.

A new hydrophobic eutectic solvent based on trioctylphosphine oxide and di-(2-ethylhexyl)phosphoric acid was obtained. The formation of HDES was confirmed by NMR and IR spectroscopy. The physical properties of the synthesized HDES were studied: density, shear and dynamic viscosity, refractive index in the range of 15-60°C. Using the method of differential scanning calorimetry, the thermal stability of HDES was studied and a phase diagram was obtained in various molar ratios. The possibility of its use as an extractant for the extraction of transition metal ions in a heterogeneous liquid-liquid system, as well as the possibility of their separation, was studied.

  • Open access
  • 21 Reads
Biotesting of soil contamination of agricultural land Prokhorovsky district of the Belgorod region
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Contamination of agricultural soils with heavy metals, antibiotics, waste from livestock complexes and toxins leads to the accumulation of these substances in crops and further transmission along the food chain.

Belgorod Region is one of the main agro-industrial regions of Russia. The volume of production of the livestock sector in 2022 amounted to 203 billion rubles. Most often, livestock farms are located near agricultural land with plant crops, which increases the risk of contamination of the latter with various toxicants.

The purpose of this work was to study and assess contamination with heavy metal ions and toxic chemicals of soils of agricultural lands and nearby reservoirs of the Prokhorovsky district of the Belgorod region. As a bioindicator, watercress Lepidium sativum and crustaceans Daphnia magna Straus were used.

5 reservoirs near agricultural lands were investigated. The water in 1,2,3 and 4 samples corresponded to the category of good quality, the D. magna mortality index did not exceed 20%. In sample 5, the mortality index of daphnia did not exceed 30%, that is, acute toxicity was not recorded in these samples.

Soil testing of 3 agricultural lands showed that, on average, the length of the roots of Lepidium sativum was 4±0.2 cm (deviation from the control of 17%), the length of the aboveground part was 15.7±0.4 cm (deviation - 13.3%), the weight of the roots was 630±17 mg (deviation – 10.2%), phytotoxicity - 79±1.2% (very low toxicity).

According to the results of biotesting, the water in reservoirs adjacent to agricultural land corresponds to Class II, the category "slightly polluted". It was revealed that the soils of agricultural lands of the agroholding have initial manifestations of toxic effects. It is necessary to regularly monitor the condition of the soil and, in case of deterioration, take measures to neutralize toxicants.

  • Open access
  • 14 Reads
Conception of a control and management system lighting with graphical user interface
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Lighting is the largest item of electricity consumption. The implementation of new technologies makes it possible to reduce the energy bill as well as the operating cost. Having an intelligent lighting system allows both the economic and commercial development of society, and guarantees adapted and more modern lighting.
In this work, we created a control and management system for the exterior lighting using creative, intelligent and autonomous methods. The project allows control room operators to monitor the system and interact when needed. Our project is subdivided into three major parts, ordering, data processing, and action. The first part is carried out in two modes, manual and controlled with a graphical interface. The second is processed by a microcontroller, an Arduino-nano in our case. As for the third part, it does the action of controlling three poles through the opto-triacs for full and half lighting.
The inputs-outputs available on the arduino card must be handled with great care. In order to control the three poles manually, we use galvanic isolation between the inputs of the microcontroller and the outside world. In other words, there will be no electrical connection between the arduino board and the external devices and the transfer of information will be done by light using an electronic component called 'optocoupler'. The mode controlled by the graphical user interface that does not require optocoupler inputs, because the microcontroller will be directly controlled by RS232 type serial communication by using MAX232 integrated circuit.
For the controlled mode, we are going to use the dimmer principle within MOC3023 optotriac integrated circuit and BTA16-600B triac . A dimmer is an electronic device designed to regulate light output of incandescent and halogen lamps with special dimming ballasts. A light dimmer works by essentially chopping parts out of the AC voltage. This allows only parts of the waveform to pass to the lamp. The brightness of the lamp is determined by the power transferred to it, so the more the waveform is chopped, the more it dims. The BTA16-600B triac output is driven by the ULN2803 via the MOC3023 optotriac.
Azero crossing control is needed for phase cutting. This is a circuit that tells the Arduino when the sinus-wave goes through zero and therefore gives a defined point on that sinus wave. The zero crossing is directly derived from the rectified mains AC lines – via an 4N35 optocoupler and gives a signal every time the wave goes through zero. Because the sine wave first goes through double phased rectification, the zero-crossing signal is given regardless whether the sinus wave goes up through zero or down through zero. This signal then can be used to trigger an interrupt in the Arduino.
The graphical application of our project has a rather sketchy design. It is divided into two windows, the first consist connection window, and the second is for the main control interface. On this control interface, there are basically three tabs, connection and serial connection status, control, and operating mode.
Thus, we can consider some improvements here and there to make this project more efficient thanks to current and voltage sensors in order to have an exact consumption of each lighting mast. The basic idea is very promising and we were able to materialize this idea by realizing a system of control and management of external lighting containing several poles of lighting.