Evaluation of adsorption performance of phosphates removal using cell‐mg hybrid adsorbent

Abstract: Due to the high accumulation of nutrients in water (primarily phosphates) because of increased use of fertilizers and plant protection products, it is necessary to apply various techniques for their detection, and then removal. Adsorption is one of the promising techniques to removing them. Magnetite (MG) modified cellulose membrane (Cell-MG), obtained by reaction of 3-aminosilane and subsequently with diethylenetriaminepentaacetic acid dianhydride functionalized waste Cell fibers (Cell-NH2 and Cell-DTPA, respectively), and amino-modified diatomite was used for phosphate ions removal from water. Cell-MG membrane was structurally and morphologically characterized using SEM and TEM techniques. The influences of operational parameters, i.e. pH, contact time, temperature, and the mass of adsorbent on adsorption and kinetics were studied in a batch system. The calculated capacities of 79.08 mg/g at 45 °C for phosphate ions were obtained from non-linear Langmuir model fitting. The reusability of adsorbent and results from wastewater purification showed that Cell-MG could be used as general-purpose adsorbent. Based on the kinetic studies the adsorption process follow the pseudo second-order model. Thermodynamic parameters showed that the adsorption process is endothermic and spontaneous

Microwawe-assisted extraction of antioxidant compounds from Vaccinium Myrtillus leaves

Vaccinium myrtillus L. (bilberry, Ericaceae), a perennial, wild, and small deciduous shrub that grows in the mountains and forests of Europe. The leaf extracts are widely used in traditional medicine due to their astringent, antiseptic, antioxidant, anti-inflammatory, hypolipidemic, and hypoglycemic activities. Microwave-assisted extraction provides various benefits, including reducing solvent consumption and extraction time and increasing extraction yield. In the present study, bilberry extracts were prepared using dried leaves, pure ethanol, or an ethanol-water mixture, and different temperatures in a microwave reactor (60, 100, and 160 ◦C). The extracts were examined in terms of total polyphenol content (TPC) and antioxidant activity. The TPC of the 96% ethanol extracts rose with the increase of the extraction temperature; the extract obtained at 60 ◦C (37.2 ± 0.5 mg gallic acid equivalents (GAE)/g of plant material)<the extract at 100 ◦C (46.6 ± 0.3 GAE/g)<the extract at 160 ◦C (55.1 ± 0.5 mg/g). The TPC of the 50% ethanol extract prepared at 60 ◦C was significantly lower (54.9 ± 1.0 mg GAE/g) in comparison to the extracts obtained at 100 and 160 ◦C (58.3 ± 1.0 and 58.0 ± 1.5 mg GAE/g, respectively). ABTS antioxidant capacity was higher in the 50% ethanol extracts compared to 96% ethanol parallels, while in the DPPH assay, there was no statistically significant difference between the 50 and 96% ethanol extracts. Due to higher TPC and anti-ABTS activity and reduced consumption of organic solvent, a 50% ethanol extract of V. myrtillus was favored, while the optimal temperature was 60 ◦C for the extract with the highest antioxidant capacity and 100 ◦C for the extract with the highest amount of polyphenols

From Aloe vera Leaf Waste to the Extracts with Biological Potential: Optimization of the Extractions, Physicochemical Characterization, and Biological Activities

In the study, the optimization of the extraction from Aloe vera leaf waste was performed via varying solid-to-solvent ratio, solvent type, extraction time, and technique (maceration, heat-, ultrasound-, and microwave-assisted extractions—HAE, UAE, and MAE, respectively). The optimal extraction conditions for achieving the highest polyphenol content are a 1:30 ratio, 70% ethanol, and 30 min of HAE. Total flavonoid and protein contents were significantly higher in the extract from MAE, while total condensed tannin content was the highest in HAE. LC-MS analysis quantified 13 anthraquinone and chromone compounds. The variations in the FT-IR spectra of the extracts obtained by different extraction procedures are minor. The influence of extraction conditions on the antioxidant ability of the extracts depended on applied antioxidant assays. The extracts possessed medium inhibition properties against Staphylococcus aureus and weak inhibitory activity against Enterococcus feacalis. The extracts had stimulative effect on HaCaT cell viability. Regarding the extraction yield, there was a significant difference between the used extraction techniques (MAE > HAE > maceration and UAE). The presented study is an initial step in the production of polyphenol-rich extracts from A. vera leaf waste aimed to be used for the potential preparation of pharmaceutical and cosmetic formulations for the skin

Sustainable development in WPCBs treatment for production of bituminous waterproofing materials

Due to the rapidly increasing use of electrical devices, e-waste became one of the major threats to the environment. Waste printed circuit boards (WPCBs) are an integral part of electrical devices, thus the interest in their recycling is growing. Recycling of WPCBs can be performed by applying hydrometallurgical or pyrometallurgical processes, as well as vacuum pyrolysis. The main advantages of vacuum pyrolysis are eco-friendliness, economic viability and efficiency in extracting present noble metals, while pyrolysis oil occurs as a by-product. Pyrolysis oil poses a tremendous threat to the environment, due to the possibility of its spillage into water, as well as a potential release into the air and soil. Because of this, the pyrolysis oil was subjected to chemical treatment with different reagents, such as sodium hydroxide, calcium oxide, sulfuric acid and maleic anhydride, with the intent to solidify the material and remove unpleasant odors. Incorporation of the solidified materials into bitumen, at 2.5, 5, 7.5, and 10 wt.% addition, was performed to obtain waterproofing materials. The obtained solidified and bituminous water-resistant materials were subjected to various test methods: FTIR spectroscopy, physicochemical and mechanical properties of bitumen, etc. which showed that all the tested characteristics are in accordance with values prescribed by the current standard. Toxicity Leaching Procedure (TCLP) confirmed non-hazardous characteristics of the obtained materials, except for the ones with added solidified pyrolysis oil, with Sodium hydroxide, that showed higher leaching of the phenol constituent

Eco-friendly Elderberry based sorbent for removing Pb2+ ions from aqueous solutions

Elderberry (Sambucus nigra) pith was modified with polyethyleneimine (PEI) in order to improve the adsorption properties. Characterization of both dried Sambucus nigra pith (DSNP) and amino modification of elderberry pith with branched PEI (PEI/DSNP) was performed by: Fourier-transform infrared spectroscopy (FTIR), optical microscopy, and porosity determination. The amine and ester number, as well as acid value, were determined on DSNP and PEI/DSNP samples using standard volumetric methods. The samples were used as adsorbents for Pb2+ ions from an aqueous solution in a batch system. The obtained results were fitted using suitable equilibrium isotherm and kinetic models. The maximum adsorption capacity for Pb2+ ions on DSNP and aminаted sample, obtained using Langmuir adsorption isotherm at 298 K, are 18.9 and 47.8 mg g-1, respectively. Based on the kinetic studies, the adsorption process follows the pseudo second-order model. Thermodynamic parameters showed that the adsorption process is endothermic and spontaneous. In general, the overall adsorption process was improved by modifying starting material with branched PEI modifier by introducing large numbers of amino functionalities having high affinity to cations

Recycled poly(ethylene terephthalate) based – plasticizers for PVC regranulates production

Due to the increasing use and widespread of plastics, poly (ethylene terephthalate) (PET) and poly(vinyl chloride) (PVC) are becoming one of the major threats to the environment. The aim of thispaper is obtaining plasticizers from recycled PET, and hot/cold mixing thereof with PVC to producenew materials. Plasticizer was obtained from PET using ethylene glycol (EG) in the presence ofcatalyst FASCAT 4100, followed by treatment with maleic anhydride and finally 2-ethylhexanol(2-EtHex). The obtained glycolysate and plasticizer, individually or mixtures thereof, were used forthe production of polygranulates based on waste PVC in order to obtain an expanded mass ofhomogenized PVC with glycolysate/plasticizer. The abovementioned procedures and test results forthe regranulates and products indicate that the proposed technology offers a solution to the problemof waste PET and PVC through transesterification in order to obtain plasticizer based on PET andEG, called 2-EtHex/MA/РG/PET/EG/MA/2-EtHex used in the processing of PVC waste and inregranulate. The obtained regranulates are further processed by injection molding or extrusion intocommercial products such as slippers, footwear, boots, garden hoses, mats, floor mats, etc

Improved technology for production of PE and PP regranulates

Management of waste polymers (polyethylene - PE and polypropylene - PP) represents one of the major obstacles in the field of environmental protection, which demands a most efficient and eco-friendly technological solution. Due to the high use of various plastic materials, the amount of landfilled or dissipated plastic waste is continuously growing. Therefore, this paper examines the possibilities of recycling these polymers, alongside obtaining granules of similar or advanced physico-mechanical characteristics to the commercially available ones. The applied technology consists of several consecutive processes (collecting, grinding, washing and extruding) where the obtained materials can later be incorporated into widely applicable products, such as foils, bin liners, bags, among others. In this way, high-quality products with great market potential are obtained, which will consequently contribute to lower extraction and less depletion of natural resources. Thus major problems may be solved optimally, consolidating the efficiency of improved eco-friendly technologies which is in line with environmental protection and sustainable waste management

Maceration and heat-assisted extraction of polyphenols from Aloe vera

Aloe vera (L.) Burm. f. (Asphodelaceae) contains anthraquinones, their glycosides, flavonoids, tannins, terpenoids, saponins, resins, mono- and polysaccharides, polypeptides, lectins, enzymes, vitamins, and minerals. The plant is used in traditional medicine due to its antitumor, antioxidant, anti-inflammatory, antiulcerogenic, immunomodulatory, analgesic, and dermal protection properties. Maceration and heat-assisted extraction (HAE) are frequently used extraction procedures because of their simple operation and low costs. In the present study, A. vera dried leaves were extracted using ethanol (50%, V/V; drug solvent ratio 1:30, w/V). The influence of different extraction times (30-120 min for maceration and 15-60 min for HAE), and various extraction temperatures (40, 60, and 80ºC) in HAE on the total polyphenol content (TPC) and radical scavenging potential (ABTS and DPPH methods) was evaluated, while for the most prominent extracts (with the highest TPC) zeta potential and conductivity were additionally analyzed. Regarding maceration, the TPC was correlated with the rise in extraction time up to 45 min (from 7.8±0.72 to 9.66±0.51 mg gallic acid equivalents (GAE)/g of plant material) and after that reached the steady state (~9.1 mg GAE/g). In HAE, no statistically significant differences between the TPC of the extracts obtained after 15, 30, and 45 min (9.77±0.32, 9.76±0.18, and 9.95±0.50 mg GAE/g) were observed, while the extract prepared after 60 min showed significantly lower TPC (8.14±0.08 mg GAE/g). The TPC was in correlation with the increase of extraction temperatures (9.08±0.21 at 40ºC, 9.38±0.10 at 60ºC, and 9.86±0.24 mg GAE/g at 80ºC). As in the case of TPC results, anti-ABTS activity was significantly different between 30 and 45 min of maceration and reached the steady state after 45 min (~2.01 mmol Trolox/g of plant material). In HAE, the anti-ABTS potential of the extracts obtained at different extraction times was comparable (1.44-1.64 mmol Trolox/g), whereas the activity of the extract obtained at 40ºC was lower. DPPH radical scavenging activity rose after 45 min of maceration when also reached the steady state (~40.4 mg/mL), but there were no significant differences between the extracts prepared at different extraction times in HAE, and IC50 was lower for the extract obtained at 80ºC. Hence, the macerate prepared after 45 min and HAE extract obtained after 15 min at 80ºC exhibited very low zeta potential (0.14±0.06 and 0.50±0.01 mV), and conductivity (1.05±0.07 and 0.98±0.01 mS/cm). This study was an initial step in the production of A. vera polyphenol extracts aimed to be used for the formulation of foodstuffs, medicines, and cosmetics.VIII International Congress “Engineering, Environment and Materials in Process Industry-EEM2023", Jahorina, March 20-23, 2023, Republic of Srpska, Bosnia and Herzegovina. Saopštenje sa međunarodnog skupa štampano u celini

Recycled Poly(ethylene Terephthalate) Based-Plasticizer for PVC Regranulates Production

Due to the increasing use and widespread of plastics, poly (ethylene terephthalate) (PET) and poly (vinyl chloride) (PVC) are becoming one of the major threats to the environment. The aim of this paper is obtaining plasticizers from recycled PET, and hot/cold mixing thereof with PVC to produce new materials. Plasticizer was obtained from PET using ethylene glycol (EG) in the presence of catalyst FASCAT 4100, followed by treatment with maleic anhydride and finally 2-ethylhexanol (2-EtHex). The obtained glycolysate and plasticizer, individually or mixtures thereof, were used for the production of polygranulates based on waste PVC in order to obtain an expanded mass of homogenized PVC with glycolysate/plasticizer. The abovementioned procedures and test results for the regranulates and products indicate that the proposed technology offers a solution to the problem of waste PET and PVC through transesterification in order to obtain plasticizer based on PET and EG, called 2-EtHex/MA/РG/PET/EG/MA/2-EtHex used in the processing of PVC waste and in regranulate. The obtained regranulates are further processed by injection molding or extrusion into commercial products such as slippers, footwear, boots, garden hoses, mats, floor mats, etc

Comparison of maceration and ultrasound-assisted extraction of antioxidant compounds from Vaccinium myrtillus L.

Vaccinium myrtillus L.(Ericaceae), a perennial, wild, and small deciduous shrub that grows in the mountains and forests of Europe, contains anthocyanins, phenolic acids, flavonoids, fatty acids, stilbenes, iridoid glycosides, dietary fibers, vitamins, and minerals. The leaves' extracts are widely used in traditional medicine due to their astringent, antiseptic, antioxidant, anti-inflammatory, skin-rejuvenating, lipid-lowering, hypolipidemic, and hypoglycemic activities. The novel extraction techniques, including ultrasound-assisted extraction, provide various benefits, such as reducing solvent consumption and extraction time and increasing extraction yield, and quality. Hence, in the present study, V. myrtillus extracts were prepared using dried leaves (0.66 g), 50% ethanol as the extraction solvent (20 mL), and maceration (60 min) or ultrasound-assisted extraction (ultrasound probe, amplitude of 60% for 5 min). The obtained extracts were examined in terms of total polyphenol content (TPC) and antioxidant activity (ABTS, DPPH, FRAP, and CUPRAC assays). The TPC of the extract prepared using maceration was 55.2±0.7 mg gallic acid equivalents (GAE)/g of plant material, while the TPC of the extract prepared using an ultrasound probe was 55.6±1.0 mg GAE/g. The DPPH radical scavenging activities of the extracts correlated with the TPC and amounted to 1.81±0.05 mg/mL for macerate and 1.79±0.02 mg/mL for the extract obtained using an ultrasound probe, whereas ABTS antioxidant capacity did not correlate with the polyphenol concentration, 31.4±0.9 µmol Trolox equivalents (TE)/g for the macerate and 43.4±1.1 µmol TE/g for the extract from the ultrasound-assisted extraction. According to the results of FRAP and CUPRAC assays, the antioxidant potential was similar for both extracts (15.3±0.2 and 15.5±0.2 µmol Fe2+/g and 45.7±0.5 and 46.0±0.7 µmol TE/g, respectively). Due to higher ABTS radical scavenging potential and significantly shorter extraction time, V. myrtillus extract prepared using an ultrasound probe was favored. The present research was an initial step in the preparation of V. myrtillus extracts which can be potentially implemented in food, pharmaceutical, and cosmetic formulations