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Item type:Наукова стаття, Optimising the adsorption characteristics of spent coffee grounds by thermal and chemical activation(Lutsk : LNTU, 2025) Moroz, IrynaThe aim of this study was to optimise the adsorption parameters of methylene blue on spent coffee grounds by combining thermal exposure and orthophosphoric acid treatment. The study was carried out using a spectrophotometric method, infrared spectroscopy, and a method for determining the specific surface area by water vapour adsorption. A possible mechanism for the adsorption of the cationic dye methylene blue on coffee grounds has been proposed. It was found that an increase in the processing temperature wasn’t led to a linear increase in the specific surface area and adsorption characteristics of spent coffee grounds. It was discovered that coffee grounds’ adsorption properties were inferior to those of untreated samples at temperatures of 400°C and 800°C. However, thermal activation of spent coffee grounds at 600°C led to a 72% increase in the specific surface area (from 561 to 958 m²/g). Treatment of the waste with 60% orthophosphoric acid solution increased the specific surface area by 23% (up to 690 m²/g) compared to untreated coffee grounds. The most effective in terms of adsorption characteristics of the adsorbent was the combined treatment of coffee grounds with orthophosphoric acid followed by thermal activation at 200°C, which provided a maximum specific surface area of 1078 m²/g and water vapour adsorption of 0.543 g of water per 1 g of sample, exceeding the characteristics of some commercial activated carbon samples. Under these conditions, the highest removal efficiency of methylene blue from model solutions was achieved – 57% in 30 min and almost 90% of the dye in 180 minutes of contact. The proposed conditions for the modification of spent coffee grounds make it possible to obtain an effective biosorbent for wastewater treatment from organic dyes, which is of practical importance for solving environmental problems in the textile and printing industries and the rational use of coffee production waste.Item type:Наукова стаття, Comparison of properties of plant-based milk and cow’s milk(NUFT, 2024) Dudarev, Igor; Moroz, Iryna; Shemet, Vasylyna; Hulai, OlhaConsumers are increasingly choosing foods that contain plant-based dairy analogues that are affordable and have high nutritional value, including macro and micronutrients and vitamins. Plant-based milk mimic the taste and consistency of cow’s milk. Plant-based milk contain no hormones or antibiotics compared to animal milk. Physical, chemical and sensory properties of plantbased milk (soy, rice-almond, rice-coconut, and oat) available on the Ukrainian market were determined and compared with those of local cow’s milk. Plant-based milk was an opaque homogeneous liquid of beige color with different tinting and it had a pleasant sweet taste with an aftertaste of raw materials. Plantbased milk had an appearance and consistency similar to cow’s milk. Titratable acidity of plant-based milk did not exceed 21 °T. Titratable acidity of cow’s milk was 16—18 °T. Dry matter content of plant-based milks was in the range of 8.73—9.83%. Dry matter content of cow’s milk was 11.63—12.52%. Density of plant-based milk was in the range of 1027—1032 kg/m3 . Density of cow’s milk was 1028—1029 kg/m3. Protein content of plantbased milk was 2.31—5.12 g/100 ml. Fat content of plant-based milk was 1.5—3.0 g/100 ml. Carbohydrate content of plant-based milk was 2.53—8.01 g/100 ml. In cow’s milk, the protein, fat and carbohydrate contents were 3.34—3.63 g/100 ml, 2.4—2.5 g/100 ml and 4.72—4.74 g/100 ml, respectively. Caloric content of plant-based milk was 46.2—64.2 kcal/100 ml. In plantbased milk, concentration of Ca2+ ions was 682—1058 mg/l and concentration of Mg2+ ions was 96—140 mg/l, which was lower than in cow’s milk. Plant-based milks are not full substitutes for cow’s milk, and their recipe composition needs to be balanced to provide the human body with the necessary nutrients.