Search

Background Results Conclusion During the processing of spent coffee grounds (SCGs) several residues are obtained, which are mostly disposed of in landfills. There is an urgent need for a comprehensive waste management strategy for these residues. This study evaluates the potential of SCGs as a biofertilizer by assessing their effects on lettuce leaves and the release of antioxidants following in vitro digestion and fermentation.Lettuce plants were grown with different amounts of SCGs (0–150 g kg−1) in the substrate. High SCG concentrations in the soil generated lighter colored tissues, a decrease in the green color, less root development, and lower dry weight of leaves (P < 0.05). The SCG levels also affected the release of antioxidants by the final product. This effect was more pronounced in the digested fraction: applying the Ferric Reducing Antioxidant Power (FRAP) method, the addition of SCGs from 10 g kg−1 to 125 g kg−1 increased the amount of antioxidant from 43.88 ± 4.81 to 105.96 ± 29.09 μmol Trolox g−1 of dry weight (P < 0.05). The Indigo Carmine Reducing Capacity (ICRED) method also showed a similar trend, but in this case the highest value was obtained with 150 g kg−1 of SCGs (16.41 ± 3.93 mmol catechin g−1 of dry weight) (P < 0.05). Moreover, in the fermented fraction a significant increase in the antioxidant released was found with low levels of SCG(P<0.05), while lettuces fertilized with intermediate amounts of SCGs (25 and 50 g kg−1) presented the highest amount of insoluble antioxidant (P < 0.05).A compromise should be found in order to achieve a product with a high antioxidant capacity and an acceptable visual quality. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The production and consumption of coffee generates large amounts of waste which, if released into the environment, could cause unacceptable pollution. The search for alternatives for the use of these waste materials, namely coffee silver skin (CSS) and spent coffee grounds (SCG), is of great importance from an environmental and economic point of view. In this context, the present study was conducted to evaluate the use of CSS and SCG as mineral sources in order to strengthen their status as novel foods, which is currently not recognised. With the aim of validating the content of metals and metalloids in CSS and SCG, a comparative study of green and roasted coffee was also conducted. The results of the HR-ICP-MS analyses showed that coffee and coffee by-products contain high levels of macro essential elements: K (2387–35 993 mg/kg), Mg (1263–5298 mg/kg) and Na (82.6–170 mg/kg). Among the essential trace elements, Fe predominated with amounts between 41.8 and 728 mg/kg. The essential elements in the ultra-trace range (Mo, Cr, Co and Se) are found in amounts between 0.02 and 2.42 mg/kg. The content of toxic elements (Pb, As, Cd and Sn) is in the range of 0.01–0.25 mg/kg, which is below the maximum levels set by the EU Commission for these elements in foodstuff. However, the levels of Rb, Ba, Sr, Ti and Al are high, and range from 2.33 to 764 mg/kg. Considering the high content of essential elements in CSSs that are useful for daily human needs, the potential use of CSS should be encouraged. On the other hand, in order to meet the requirements for the use of novel foods, monitoring of potentially toxic elements must be carried out. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the present study, cold atmospheric plasma (CAP) was employed as a pretreatment method for the extraction of phenolic compounds from spent coffee grounds (SCGs). The impact of CAP treatment conditions, i.e., thickness of the SCGs layer (mm), distance between the plasma source and the SCGs layer (mm) and duration of CAP treatment (min), on the total phenol content, in vitro antioxidant activity, as well as caffeine and chlorogenic acid content of SCGs, was investigated. The process parameters were optimized with the aid of response surface methodology (RSM). After optimizing the CAP pretreatment conditions, the CAP-treated SCGs were subjected to ultrasound-assisted extraction using ethanol as the extraction solvent. The optimum conditions for CAP treatment identified, i.e., thickness, 1 mm; distance, 16 mm; and duration, 15 min, led to a significant enhancement in the recovery of bioactive compounds from SCGs compared to those obtained from untreated SCGs. Total phenolic content and antioxidant activity significantly increased (i.e., TPC from 19.0 ± 0.7 to 24.9 ± 1.4 mg GAE/100 g dry SCGs, ADPPH from 106.7 ± 5.01 to 112.3 ± 4.3 μmol Trolox/100 g dry SCGs, AABTS from 106.7 ± 5.01 to 197.6 ± 5.8 μmol Trolox/100 g dry SCGs, ACUPRAC from 17938 ± 157 to 18299 ± 615 μmol Trolox/100 g dry SCGs). A significant increase in caffeine content from 799.1 ± 65.1 mg to 1064 ± 25 mg/100 g dry SCGs and chlorogenic acid content from 79.7 ± 15.3 mg to 111.3 ± 3.3 mg/100 g dry SCGs, was also observed. Overall, CAP pre-treatment can be used to enhance the recovery of bioactive compounds from SCGs. [ABSTRACT FROM AUTHOR]

Almost, spent coffee grounds are discarded to landfill, causing bad impacts on natural environment and generating a great waste because of removing beneficial bioactive compounds. This study investigated effects of dyeing techniques (exhaustion and pad-dry), types of mordants, sequences of adding mordants, temperature, exhausting time and concentration on dyeability of coffee extracts for cotton fabric in terms of color strength (K/S) and color difference (ΔE), thereby proposing a suitable treatment procedure. The experimental results showed that K/S and ΔE values were highest when mordanting with FeSO4.7H2O and CuSO4.5H2O. Simultaneously, highly antioxidant and antibacterial properties of treated cotton were quantitatively evaluated by UV-vis spectroscopy, scanning electronic microscopy, microbiologicalmethod and mechanical experiments. The content of polyphenols and tannins as well as the bacteriostatic activity of gram-positive and gram-negative species on treated cotton fabrics with coffee extracts were promising in future applications. Particularly, the total amounts of polyphenols and tannins, which could demonstrate antioxidant activity, were examined as 3.01 g/L (GAE) and 0.57 g/L (TAE), respectively. Especially, high reduction of E. coli bacteria and S. aureus bacteria on dyed specimens accounted for 78% and 80% as mordanting with CuSO4.5H2O, and it could be sustained to 75% and 48% after a washing cycle, respectively. [ABSTRACT FROM AUTHOR]

Second-stage juveniles (J2) of Meloidogyne species are known to be repelled by several compounds. Although such repellents could serve for nematode control, effective, practical and sustainable repellents are unknown. The present study tested instant coffee crystals (ICC) and a methanolic extract of spent coffee grounds (SCG) for their repellency against, and infection inhibition of, J2 of Meloidogyne species on agar plate assays. J2 of Meloidogyne javanica, M. hapla and M. marylandi were repelled by the SCG extract and ICC. When ICC were mixed with chemical J2 attractants, their attractiveness to M. javanica J2 was reduced or abolished. ICC and the SCG extract deposited near lettuce seedling roots on the agar plate reduced the number of M. javanica, M. incognita, and M. hapla J2 attracted to the root tips by 84.3-96.4%, decreased infection rates by 37.5-75.0%, and increased root length 1.3- to 2.8-fold compared to seedlings grown on the non-treated side of the same plate. Thoroughly mixing the SCG extract into the plated agar reduced the number of J2 of the three species attracted to lettuce root tips by 46.7-98.6% and the infection rate by 87.5-95.8%, and increased the root length of the seedlings up to 2.8-fold, although no nematicidal effect was found. The same SCG-treated agar plate reduced the attraction of M. javanica J2 to a chemical attractant. The results suggest that ICC and the SCG extract have repellent and infection-inhibitory activity against Meloidogyne J2 and are potential control means for Meloidogyne species. [ABSTRACT FROM AUTHOR]

ABSTRACT In this research, bimetallic CdNi nanoparticles encapsulated in a magnetic spent coffee ground (Fe3O4@COFF/CdNi) was synthesized as a new nanocatalyst. The structural and chemical characteristics of Fe3O4@COFF/CdNi were comprehensively investigated using various techniques, including FT‐IR, XRD, XPS, TEM, VSM, EDS, TGA, BET, and ICP. Through XRD, XPS analysis, TEM images, and EDS mapping, the presence of CdNi nanoalloys was conclusively established. Fe3O4@COFF/CdNi exhibited remarkable catalytic activity for the hydrogen generation from water using iso‐propanol as a clean sacrificial agent. The high catalytic performance of Fe3O4@COFF/CdNi was attributed to the synergistic cooperative effect of Cd and Ni within CdNi nanoalloys. Interestingly, this process was performed for the in situ generated hydrogen from water to reduce a range of nitrobenzenes simultaneously into the corresponding anilines in high yields (93%–98%). The magnetic and hydrophilic characteristics of Fe3O4@COFF/CdNi facilitated its reusability over five runs. Using water as the most abundant hydrogen source, for the first time for in situ hydrogen generation–reduction of nitrobenzenes without demanding on external light sources or power supplies can be mentioned as a significant milestone of this field of study. [ABSTRACT FROM AUTHOR]

BACKGROUND: The industrial‐scale application of enzymes faces obstacles due to elevated costs and difficulties in stability and reuse. In this study, magnetic spent coffee grounds, an ecotoxic waste, have been utilized successfully for the first time to immobilize β‐glucosidase to overcome these challenges. RESULTS: The spent coffee grounds were magnetized and amine‐functionalized, followed by characterization using various techniques. Under optimized conditions, forming an imine bond between the functionalized support and β‐glucosidase resulted in a 62% immobilization yield (92.81 mg g−1 enzyme loading) and 12.5 U mg−1 activity after immobilization. A relatively small kinetic change was observed in the Km value (902 to 946 μmol L−1) after immobilization, suggesting minimal hindrance by AMSCG3 on substrate access or product release. Moreover, Glu@AMSCG3 showed exceptional stability (>90% residual activity) within a pH range of 3 to 6 after 2 h of incubation at 25 °C. A residual activity of 87.94% was maintained even at 80 °C and pH 5 after 2 h of incubation compared to the free β‐glucosidase, which showed only 6.5% residual activity at the same temperature. When cellobiose was hydrolyzed using Glu@AMSCG3 under optimum conditions, 91.33% cellobiose conversion was achieved initially, and over 79% conversion was maintained for 10 reusability cycles. CONCLUSION: The improved stability of β‐glucosidase after covalent immobilization on amine‐modified magnetically separable spent coffee grounds indicates their potential as a support matrix for application in enzyme immobilization. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Sugar and coffee industries produce considerable amounts of sugarcane bagasse and spent coffee grounds as waste products, these products having very limited value—plant fertilizer for the former and livestock feed or energy source for the latter-. Their valorization potential as construction materials in the built environment is being investigated. In this work, a higher value use of these two agri-wastes is presented through the elaboration and characterization of an environmentally friendly composite material (Starch-bonded sugarcane Bagasse spent Coffee Composite SBCC) for building applications, based on starch-bonded spent coffee grounds reinforced with sugarcane bagasse fibers. The advantages of fiber reinforcement are evaluated by comparison with a previously studied composition solely based on starch and coffee grounds. Samples are characterized in terms of absolute and bulk density, sound absorption coefficient, compressive strength, as well as hygrothermal properties. Fiber incorporation led to a relatively lighter material than the non-reinforced ones, with a bulk density of 321 kg.m−3 while presenting increased mechanical properties, withstanding maximum compression stress of 2.8 MPa, and presenting Young's modulus of 3.15 MPa. Both thermal conductivity (0.088 W.m−1.K−1) and diffusivity showed a good thermal insulation capacity (0.2 m2.s−1) of the bagasse-reinforced composite. The potential of this new non-structural composite as an acoustic insulator is also assessed, results show that the addition of bagasse did not affect sound absorption compared to the previously studied composites without fibers. In light of the experimental characterization, this new composite would be suitable for use as a non-structural material in building applications. Statement of Novelty: The novelty lies in the association of these two types of co-products (Sugarcane bagasse and Spend Coffee grounds) which can be found on a large scale. [ABSTRACT FROM AUTHOR]

Orange and coffee grounds by-products, rich in phenolic bioactive compounds, can be used in the food industry as antioxidants, colorants, flavorings and additives, mainly because they are solvents that are easy to prepare, have a lower cost, are thermally stable, biodegradable, renewable, and are considered GRAS (Generally Recognized as Safe). Deep eutectic solvents, which are sustainable and have lower melting points, are effective for extracting these compounds. This study aimed to evaluate the use of deep eutectic solvents (DES) in extracting Total Phenolic Compounds (TPC), from orange by-products and spent coffee grounds. DES formed by citric acid: mannitol (CM-DES), and lactic acid: glucose (LG-DES), were evaluated by varying the following parameters: water content (10–50%), solid–liquid ratio (1:5–1:50 w/w) and temperature (40–50 °C). DES citric acid: mannitol presented the best efficiency in the extraction of TPC under the conditions of 10% water, 80 °C, and solid–liquid ratio 1:10 (w/w) for the orange by-products (1782.92 ± 4.50 mg GAE/L) and 1:15 (w/w) for spent coffee grounds (1620.71 ± 3.72 mg GAE/L). The highest antioxidant activity was observed in the extraction with CM-DES for both by-products in the three methods evaluated: Ferric Reducing Antioxidant Power (FRAP) (1.087 ± 0.004 and 1.071 ± 0.006 mol ascorbic acid/L), DPPH radical scavenging activity (2,2-difenil-1-picrilhidrazil—DPPH) (0.233 ± 0.003 and 0.234 ± 0.001 mol Trolox equivalent/L), and radical cation scavenging activity ABTS (2,2-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid—ABTS) (0.284 ± 7.16 and 0.319 ± 0.002 mol Trolox equivalent/L). Therefore, DES with citric acid: mannitol is a promising alternative to conventional solvents to recover phenolic compounds in agro-industrial by-products, such as orange by-products and SCG. [ABSTRACT FROM AUTHOR]

In order to reduce global warming, new energy fuels that use waste biomass to replace traditional coal are rapidly developing. The main purpose of this study is to investigate the feasibility behavior of different biomass materials such as spent coffee grounds (SCGs) and spent tea grounds (STGs) as fuel during combustion and their impact on the environment. This study involves using fuel shaping and co-firing methods to increase the fuel calorific value and reduce the emissions of pollutants, such as NOX and SO2, and greenhouse gas CO2. The produced gas content was analyzed using the HORIBA (PG-250) laboratory combustion apparatus. The results indicate that, among the measured formed particles, SCG:STG = 8:2, 6:4, and 4:6 had the lowest post-combustion pollutant gas emissions. Compared to using only waste coffee grounds as fuel, the NOx emissions were reduced from 166 ppm to 102 ppm, the CO emissions were reduced from 22 ppm to 12 ppm, and the CO2 emissions were reduced from 629 ppm to 323 ppm. In addition, the emission of SO2, the main component of acid rain, was reduced by 20 times compared to the combustion of traditional fuels. The SO2 emission of five different proportions of biomass fuels was 5 ppm, which is much lower than that of traditional coal fuels. Therefore, SCG and STG mixed fuels can replace coal as fuel while reducing harmful gasses. [ABSTRACT FROM AUTHOR]

Due to its nitrogen, phosphorus, and magnesium content, sewage sludge is used, among other things, to grow plants for energy purposes or to intensify biogas production. These processes are always accompanied by odor emissions, which are treated as pollution according to European legislation and are subject to legal regulations in many countries. Therefore, this publication presents the results of a study on the removal of odor from sewage sludge by adsorption on biochars produced from selected biowaste. Beekeeping waste (grain) and coffee brewing residues (spent coffee grounds) were selected for the study. Both materials were pyrolyzed to produce biochar which was applied for adsorption of odors from sewage sludge. Commercial Organosorb 200-1 Wi activated carbon was used as a comparison material. The odors were taken from dried sewage sludge from a municipal wastewater treatment plant. The obtained biochars are suitable for odor adsorption and can be an alternative to commercial adsorbents. The biochar from beekeeping waste showed the highest efficiency, allowing 100% odor removal. Slightly worse results were obtained for biochar from spent coffee grounds. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) capture has been identified as a potential technology for reducing the anthropic emissions of greenhouse gases, particularly in post-combustion processes. The development of adsorbents for carbon capture and storage is expanding at a rapid rate. This article presents a novel sustainable synthesis method for the production of chitosan/activated carbon CO2 adsorbents. Chitosan is a biopolymer that is naturally abundant and contains amino groups (–NH2), which are required for the selective adsorption of CO2. Spent coffee grounds have been considered as a potential feedstock for the synthesis of activated coffee grounds through carbonization and chemical activation. The chitosan/activated coffee ground composite microspheres were created using the emulsion cross-linking method with epichlorohydrin. The effects of the amount of chitosan (15, 20, and 25 g), activated coffee ground (10, 20, 30, and 40%w/w), and epichlorohydrin (2, 3, 4, 5, 6, 7 and 8 g) were examined. The CO2 capture potential of the composite beads is superior to that of the neat biopolymer beads. The CO2 adsorbed of synthesized materials at a standard temperature and pressure is improved by increasing the quantity of activated coffee ground and epichlorohydrin. These findings suggest that the novel composite bead has the potential to be applied in CO2 separation applications. [ABSTRACT FROM AUTHOR]

Coffee beans, a popular commodity in the world, are processed into coffee, which generates a considerable quantity of spent coffee grounds (SCGs). However, SCGs, a byproduct rich in hemicellulose, poses a challenge due to fermentable sugar loss during conventional pretreatment. This study investigates the efficient production of bioethanol from SCG using an optimized liquid hot water (LHW) pretreatment combined with separate hydrolysis and fermentation (SHF) process. LHW pretreatment at 180 °C for 20 min with a high solid-to-liquid ratio (SLR) of 1:6 (w/v) was optimized to disrupt the lignocellulosic structure and retain high levels of fermentable sugars, which included mannose and glucose. This approach achieved a bioethanol concentration of 15.02 ± 0.05 g/L and a productivity rate of 1.252 g/(L·h), demonstrating the efficiency of this integrated process. Interestingly, the high SLR LHW pretreatment significantly reduces water usage and enhances product concentration, offering a promising, environmentally friendly, and economically viable method for industrial bioethanol production from SCGs without the necessity of detoxification. [ABSTRACT FROM AUTHOR]

Modified clay granules were used to promote Azotobacter vinelandii cell adhesion. The A. vinelandii cells in the clay granules were used as a biofertilizer and a plant material. The production process was carried out under variable temperatures. The raw ingredients consisted of clay, sawdust waste, and spent coffee grounds in different ratios. Scanning electron microscopy (SEM) was used to analyze the microstructure. The results of the study showed the addition of sawdust waste and spent coffee grounds had increased the water absorption of the fired clay granules based on their porosity. However, increasing the firing temperature in the range of 900°C - 1100°C decreased the water absorption and porosity and increased the bulk density of the fired clay granules. A. vinelandii was enriched to be used as a cell suspension. The fired clay granules were immersed in a cell suspension to immobilize the A. vinelandii cells for 48 h. The SEM-based investigations indicated that the fired clay granules were suitable for containing A. vinelandii cells. The results demonstrated high viability of bacterial cells fixed in the fired clay granules at 2.7× 107 CFU/g. Furthermore, the test results of bacterial cells in the fired clay granules for marigold planting media revealed that it had effectively encouraged plant growth. The nitrogen-fixing bacterial cells in the clay granules obtained from this research were determined to be appropriate for use as an ecological soil replacement in the future. [ABSTRACT FROM AUTHOR]

This study reports on the application of an innovative plastering system that reuses organic waste, namely spent coffee grounds (SCG), to improve energy efficiency in historical buildings according to the European Green Deal. The case study was conducted in the village of Polizzi Generosa, selected from 21 small villages located in the extensive UNESCO Geopark of Madonie Park in Sicily. Over time, traditional plasters used in Madonie buildings have shown durability issues due to thermal and hygrometric stresses caused by significant temperature fluctuations in the area. Moreover, much of the considered architectural heritage lacks energy efficiency. Given the global increase in coffee production and the need for more sustainable waste management systems, this investigation proposes an ecological method to reuse SCG in plaster formulation, thereby enhancing the circular economy. To achieve this, many thermoplaster formulations were developed, and the best-performing one, considering both material and aesthetic compatibility with historical buildings, was selected for a real-world application. Additionally, virtual modeling and energy simulations were conducted to test the energy performance of a traditional building in Polizzi Generosa using SCG-based thermoplaster in comparison to traditional lime mortar and commercial alternatives. The real-world application demonstrated the technical feasibility of the process, and the energy simulations showed an improved building masonry energy performance of 0.788 W/m2K and an 11% improvement compared to traditional plaster. Results clearly indicate that SCG can be successfully reused to produce eco-friendly bio composite plasters, providing a more sustainable housing option. This approach offers a durable and cost-effective alternative for housing solutions that meet regulatory requirements for energy efficiency, serving as a smart, highly sustainable, and long-lasting choice for the construction sector. Finally, this result supports the research goal of transforming the 21 municipalities of Madonie into smart and green villages, with the "Smart Coffee-House" exemplifying intelligent rehabilitation processes of existing heritage buildings. [ABSTRACT FROM AUTHOR]

This study explores the utilization of Spent Coffee Grounds (SCG), a residual product of the coffee industry, as a microfiller reinforcement in Poly‐3‐hydroxybutyrate‐co‐3‐hydroxyvalerate (PHBV) biopolymer composites at varying concentrations (1%, 3%, 5%, and 7%). Melt compounding via a twin‐screw extruder and subsequent compression molding were employed in the fabrication process. The SCG microfiller, with particle diameters ranging from 1.11 to 1.28 μm, exhibited a significant negative charge (zeta potential: −20 mV). Hydrophobicity increased up to 5% filler concentration, as indicated by higher water contact angles, but diminished at highest concentration likelihood of agglomeration of the spent coffee grounds within the biopolymer matrix. The addition of SCG enhanced overall mechanical properties, particularly at a 5% filler concentration. Field Emission Scanning Electron Microscopy (FE‐SEM) and Atomic Force Microscopy (AFM) confirmed the successful incorporation of SCG microfiller, improving structural characteristics. Schematic drawings illustrated the interphase bonding of microfiller and matrix. However, properties diminished at the highest filler content (7%) due to coffee grounds' agglomeration. Despite this, SCG incorporation enhanced functional properties, making the biopolymer composite a promising material for sustainable packaging and various applications. Highlights: Enhancement of properties of spent coffee grounds in PHBV biocomposites.Characterization of Biocomposites for multifunctional properties.Fracture and 2D analysis of the tensile fractured surface of biocomposites.A promising material for sustainable and biodegradable packaging. [ABSTRACT FROM AUTHOR]

AbstractThe growing popularity of cold-brewed coffee has resulted in large amounts of localized spent coffee grounds (SCG) generated from production plants. Spent coffee grounds offer many favorable agronomic properties, but also contain caffeine, tannins and phenolic compounds that may be deleterious to plant growth. There is a growing body of research examining the effects of SCG on plants, but little of which pertains to use in turfgrass systems. The objective of this two-year field study was to evaluate the feasibility of using SCG as an agronomic source of nutrients for turfgrass. Field studies were conducted over two years to characterize performance of ‘Riley’s Super Sport’ (Celebration®) bermudagrass (Cynodon dactylon) receiving multiple nutrient source treatments including fresh and composted SCG, as well as synthetic, natural organic, and bridge fertilizers, some which included SCG. Soils were analyzed at the conclusion of the study to determine whether SGC provided long-term effects of on soil pH and/or nutrient concentrations. Our results demonstrated that although SCG possesses between 2.3-2.9% N and a favorable C:N ratio, direct SCG applications over two seasons did not produce responses typical of a fertilizer when applied as a topdressing. However, when combined with poultry litter, the SCG-containing organic fertilizer GeoJava produced improved turf quality relative to other organic and synthetic commercial fertilizers in our study, including Milorganite, ammonium sulfate, and URI-PEL S.R. Further, despite the acidic nature of SCG, their repeated application over multiple years did not result in any long-term changes to soil pH. Although early on, SCG treatments caused mild and transient phytotoxicity, these effects were not observed when it was applied in combination with the manure used in GeoJava. [ABSTRACT FROM AUTHOR]

This research aims to enhance natural rubber (NR) properties by incorporating spent coffee grounds (SCGs). Scanning electron microscope (SEM) reveals well‐dispersed SCG particles in the NR matrix without interaction. Shore A hardness notably increases by up to 49.90 (19% higher than unmodified), but tensile and tear strength decline with higher SCG levels. Optimal tear strength occurs at 10 phr of SCG due to uniform dispersion. The 300% modulus remains unchanged. The odor of composites (CO2 absorption) sees a 69.2% increase at 25 phr, while odor absorption efficiency peaks at 2%. Additionally, unmodified SCG affects scorch time (2.12%–23.40% increase from 1 to 20 phr) and cure time (3.12% to 76.82% improvement from 1 to 20 phr). These findings showcase improved hardness, enhanced CO2 absorption capacity, and effective odor control. Additionally, this study sheds light on the influence of SCG on processing times, contributing valuable insights for eco‐friendly applications. [ABSTRACT FROM AUTHOR]

A novel electrochemical sensor was developed for the detection of lead (Pb) and copper (Cu) ions using spent coffee grounds decorated with iron oxide particles (FeO/SCG). The FeO-decorated SCG was used to modify a glassy carbon electrode (GCE). FeO, SCG, and FeO/SCG were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The electrochemical properties of the modified electrode were characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electrode modifications increased the active surface area and electron transfer and enhanced the accumulation of the target analyte. In the optimal condition, the developed sensor showed linear ranges of 1.0 µg L−1–0.05 mg L−1 and 0.05 mg L−1–0.8 mg L−1 for Pb2+ and 5.0 µg L−1–0.1 mg L−1 and 0.1 mg L−1–0.8 mg L−1 for Cu2+. The limit of detection (LOD) was 1.0 µg L−1 for Pb2+ and 2.4 µg L−1 for Cu2+. The developed sensor was successfully applied to determine Pb2+ and Cu2+ in bullet holes. The results were in good agreement with those obtained by inductively coupled plasma optical emission spectrometry (ICP/OES). [ABSTRACT FROM AUTHOR]

Coffee consumption is a daily habit for the majority of people worldwide, resulting in consistently large amounts of residue. Spent coffee ground (SCG) is the residue obtained during the brewing process. It represents an abundant source of energy biomass, or raw material for added value products but it is still largely unexploited. This residue may find several applications, such as in polymers/composites precursors, solid/liquid biofuels, biofertilizers, and so forth. The aim of the present paper was the pilot production of pellets by mixing SCG and other residual biomass feedstock. Coffee residues were mixed at different ratios (0, 10, 30, 50, 70, 90 wt%) together with: (i) forestry residues; (ii) sawmill residues; (iii) urban prunings; (iv) maize residues; (v) peach prunings; and (vi) miscanthus. Samples of each fuel mixture were analyzed at the Solid Fuels Laboratory of CPERI/CERTH (Chemical Process and Energy Resources Institute/Centre for Research and Technology Hellas) in Greece by applying established standards. The results of the analyses show that the mixing of biomass residues with coffee could result in competitive solid biofuels. More specifically, pellets with up to 10% coffee residues, mixed with sawmill residues, complied with the class A2 limits set by the international standard ISO 17225‐2 for wood pellets, and pellets with up to 30% coffee residues complied with the class B limits for wood pellets for commercial/residential applications. Urban prunings mixed with 10 wt% coffee residues are within the limits set for class B wood pellets. [ABSTRACT FROM AUTHOR]

Purpose: Globally, Colombia is recognized as a coffee-growing country par excellence, which entails generating a large amount of coffee waste. This narrative study aims to review the possible use of such coffee waste to obtain nutrient-rich compost following key composting processes. The final is to investigate the importance and suitability of this compost type. Method: The data collected for this study were from reviewing the scientific literature and research reports available in many reputable academic databases, i.e., Science Direct, Springer, PubMed, and Scopus. Reputable academic search engines like Google Scholar and ResearchGate were used to access relevant research and high-quality scientific documents. Results: The result revealed that using combinations of agro-industrial coffee waste when composted can be applied in agriculture because it provides wide-ranging nutrients, which can fertilize soil, accelerate plant growth, and even improve the nutrient content of vegetables. The SCGs used in agriculture prevent improper waste disposal by decreasing the pollution caused by the degradation of SCGs’ toxic components. Here we explore and review composting processes containing coffee waste. Conclusion: Employing coffee waste for compost implies benefits compared to landfills. The conversion of this coffee biomass waste into compost, and using it as a soil amendment, can reduce the waste volume, improve soil physico-chemical properties, enhance the nutrient use efficiency of crops, and correct the typical soil acidity of Colombian soils used for coffee production. [ABSTRACT FROM AUTHOR]

To maximize the efficiency of biomass waste utilization and waste management, a novel acid-modified magnetic biomass spent coffee grounds (NiFe2O4/SCG) was obtained by pyrolysis at 473 K and co-precipitation methods and employed to eliminate bivalent mercury (Hg(II)) in water bodies. The prepared NiFe2O4/SCG adsorbent exhibits remarkable magnetism with a strength of 45.78 emu/g and can easily be separated from water via a magnetic force. The adsorption of Hg(II) over the NiFe2O4/SCG has an optimal conditions of pH = 8, T = 39 ℃, and dosage of 0.055 g/L, and the maximal adsorption capacity for Hg(II) is 167.44 mg/g via Response Surface Methodology optimization. The removal of Hg(II) over NiFe2O4/SCG primarily involves ion exchange, electrostatic attraction, and chelation; conforms to the pseudo-second-order kinetic and Langmuir models; and is an endothermic reaction. Additionally, the magnetic biomass NiFe2O4/SCG has good regeneration capability and stability. The application research reveal that inorganic salt ions, nitrogen fertilizer urea, humus, and other contaminants in different actual water bodies (river water, lake water, and the effluent of sewage treatment plant) have little effect on the adsorption of Hg(II) over the NiFe2O4/SCG. The prepared adsorbent NiFe2O4/SCG has practical application value for removing Hg(II) from water bodies. [ABSTRACT FROM AUTHOR]

This paper presents an optimization study of spent coffee grounds (SCG) as cement mortar additives to enhance mortar strength. In recent years, sustainable materials have begun finding their way into cement mortar, with SCG being one. There is limited optimization study on the SCG addition in mortars, hence this study was performed to optimize the curing time and SCG addition in cement mortar to achieve the highest compressive strength through response surface methodology. Scanning Electron Microscopy (SEM) characterization was carried out on the SCG particles to identify their physical properties. An Energy Dispersive X-ray (EDX) analysis was carried out to identify its chemical properties. Simultaneously, a workability test, the flow table test, is conducted to study the effect of SCG on the flowability of the cement mortar mixes. The synergistic effect between SCG content in cement mortar mixes and the curing period was statistically studied and analyzed. Both parameters were then optimized to obtain the best performance mix of SCG in cement mortar. It was found that 1.1% SCG and a curing day of 68 days produced the highest compressive strength (33.4MPa) of cement mortar. The Response Surface Methodology (RSM)-optimized cement mortar mix presented at least a 12.62% improvement in compressive strength from control cement mortar without SCG additives (28.77MPa). Experimental validation of the optimum condition showed a good agreement with a deviation of 3.12% in three replicates, thus indicating that the optimum model in this work can be used to model the compressive strength of the SCG-cement mortar mixture.Article Highlights: The addition of spent coffee grounds (SCG) in cement mortar enhanced its strength by 12.6%. The optimum SCG addition that corresponds to the highest mortar strength is 1.1%. The flowability of cement mortar mix decreases as the percentage of SCG addition increases. [ABSTRACT FROM AUTHOR]

A biochar-incorporated g-C 3 N 4 composite was obtained by co-calcining the mixture of spent coffee grounds and melamine and used to anchor highly dispersed amorphous cobalt boride nanoparticles via an impregnation-reduction method. The as-prepared Co 2 B/BC-g-C 3 N 4 was applied to the catalytic hydrolysis of sodium borohydride to produce hydrogen. The physicochemical properties of Co 2 B/BC, Co 2 B/g-C 3 N 4 , and Co 2 B/BC-g-C 3 N 4 were evaluated by various techniques to help elucidate the effect of the composite structure on the performance of Co 2 B/BC-g-C 3 N 4. The Co 2 B/BC-g-C 3 N 4 exhibits much better activity than Co 2 B/BC and Co 2 B/g-C 3 N 4 because of a synergistic effect between the biochar and g-C 3 N 4. In addition, the reaction kinetics can be improved by exposing the reaction system to visible light irradiation, yielding a hydrogen generation rate of 10.3 L min−1 g Co −1 in comparison to that of 9.1 L min−1 g Co −1 under darkness. The possible mechanism of the H 2 generation from the catalytic hydrolysis of sodium borohydride over Co 2 B/BC-g-C 3 N 4 under visible light irradiation was proposed. This work highlights the potential application of biochar-incorporated g-C 3 N 4 composite in synthesizing metallic catalysts and their practical use for photo-assisted catalytic hydrolysis of sodium borohydride. [Display omitted] • A biochar-g-C 3 N 4 composite is prepared by co-calcination of spent coffee and melamine. • Co 2 B nanoparticles are immobilized on the BC-g-C 3 N 4 composite. • Co 2 B/BC-g-C 3 N 4 exhibits improved activity toward hydrolysis of NaBH 4 under visible light irradiation. • A possible reaction mechanism of photo-assisted NaBH 4 hydrolysis for H 2 release is proposed. • Regulation of the local electron density of Co active sites occur under visible light irradiation. [ABSTRACT FROM AUTHOR]

With growing concern over environmental sustainability and dwindling fossil resources, it is crucial to prioritise the development of alternative feedstocks to replace fossil resources. Spent coffee grounds (SCGs) are an environmental burden with an estimated six million tons being generated on a wet basis annually, globally. SCGs are rich in cellulose, lignin, protein, lipids, polyphenols and other bioactive compounds which are important raw materials for use in industries including pharmaceuticals and cosmetics. Furthermore, the energy sector has the potential to capitalize on the high calorific value of SCGs for biofuel and biogas production, offering a sustainable alternative to fossil fuels. SCGs are readily available, abundant, and cheap, however, SCGs are currently underutilized, and a significant amount are dumped into landfills. This review explores the potential of SCGs as a source of a value-added compound through various conversion technologies employed in the valorisation of SCGs into biochar, biofuel, and important chemical building blocks. The state-of-the-art, current knowledge, future research to stimulate the creation of sustainable products, and the challenges and economic feasibility of exploring SCGs in a biorefinery context are presented. [ABSTRACT FROM AUTHOR]

Biomass‐derived materials can help develop efficient, environmentally friendly and cost‐effective catalysts, thereby improving the sustainability of hydrogen production. Herein, we propose a simple method to produce nickel and molybdenum composites decorated spent coffee grounds (SCG) as an efficient catalyst, SCG(200)@NiMo, for electrocatalytic hydrogen production. The porous carbon supporter derived form SCG provided a larger surface, prevented aggregation during the high temperature pyrolysis, optimized the electronic structure by N and provided a reducing atmosphere for the oxides reduction to form heterojunctions. The sieved SCG showed obvious improvement of HER performance and enhanced conductivity and long‐term durability. The obtained SCG(200)@NiMo exhibits the highest electrochemical performance for the hydrogen evolution reaction process, as evidenced by the overpotential of only 127 mV at a current density of ɳ10 and 97.7 % catalytic activity retention even after 12 h of operation. This work may stimulate further exploration of efficient electrocatalysts derived from biomass. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study aimed to produce activated carbon (AC) from spent coffee (Coffea arabica) grounds by chemical activation using zinc chloride (ZnCl2) and nitric acid to remove bentazone from aqueous solutions. RESULTS: The fresh spent coffee grounds were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and the AC by X‐ray diffraction (XRD), infrared spectroscopy (FTIR), Brunauer–Emmett– Teller (BET), point of zero charge, scanning electron microscopy (SEM) and the Boehman method. Adsorption experiments were carried out in a batch system. The results showed a 70% efficiency in bentazone removal using ZnCl2 carbon. Kinetic studies indicate that the adsorption rate increased slowly up to 720 min; the first‐ and second‐order models fitted the experimental data at a concentration of 50 mg L−1. The adsorption equilibrium is represented by the Langmuir model with a high adsorption capacity of 279.33 ± 6.29 mg mg−1. The adsorption efficiency was also confirmed by toxicity analysis of the effluent with bentazone at 50 mg L−1, using the Allium cepa bioassay, a high‐sensitivity test for pollutants in water. CONCLUSION: Before adsorption, the effluent caused significant cytogenotoxicity to onion root meristems. After adsorption, the generated effluent no longer caused toxicity to the test system, and the results obtained were similar to the control with distilled water. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

This research examined the potential for utilizing waste materials generated during the production of dishes/meals and organic waste. Specifically, it evaluated the use of orange peel (OP), spent coffee grounds (SCG), and waste cooking oil in the production of soaps. For the purposes of this study, homemade soaps were made from used food oils using the cold saponification method using sodium hydroxide. During the soap preparation, spent coffee grounds and orange peel were added to the samples in increasing concentrations of 1%, 2.5%, and 5%. The quality of the individual types of homemade soaps was evaluated on the basis of physicochemical properties such as pH, moisture, total alkalinity, total fatty matter, malondialdehyde content, fat content, foaminess, and hardness. All soaps produced using the cooking oil met the ISO quality criteria and reveal a high TFM content, low moisture content, and also very good foam stability and satisfactory foaming stability. However, no relationship was observed between the use of OP and SCG in soap production and these parameters. However, according to the ABTS test, OP and SCG significantly contributed to the antioxidant properties of the soaps, while SCG-impregnated soaps performed slightly better in this respect. Soaps with SCG also had the highest levels of flavonoids. On the other hand, the fillers used for the soap formulation reduced their hardness. All soaps showed 100% solubility in water, thus confirming the biodegradability of the product. This study demonstrated the novel potential of incorporating waste products like orange peel, spent coffee grounds, and waste cooking oil into homemade soaps, highlighting their contributions to its antioxidant properties and water solubility while ensuring high quality standards. [ABSTRACT FROM AUTHOR]

Lignocellulosic residues (LRs) are one of the most abundant wastes produced worldwide. Nevertheless, unlocking the full energy potential from LRs for biofuel production is limited by their complex structure. This study investigated the effect of N-methylmorpholine N-oxide (NMMO) pretreatment on almond shell (AS), spent coffee grounds (SCG), and hazelnut skin (HS) to improve their bioconversion to methane. The pretreatment was performed using a 73% NMMO solution heated at 120 °C for 1, 3, and 5 h. The baseline methane productions achieved from raw AS, SCG, and HS were 54.7 (± 5.3), 337.4 (± 16.5), and 265.4 (± 10.4) mL CH4/g VS, respectively. The NMMO pretreatment enhanced the methane potential of AS up to 58%, although no changes in chemical composition and external surface were observed after pretreatment. Opposite to this, pretreated SCG showed increased porosity (up to 63%) and a higher sugar percentage (up to 27%) after pretreatment despite failing to increase methane production. All pretreatment conditions were effective on HS, achieving the highest methane production of 400.4 (± 9.5) mL CH4/g VS after 5 h pretreatment. The enhanced methane production was due to the increased sugar percentage (up to 112%), lignin removal (up to 29%), and loss of inhibitory compounds during the pretreatment. An energy assessment revealed that the NMMO pretreatment is an attractive technology to be implemented on an industrial scale for energy recovery from HS residues. [ABSTRACT FROM AUTHOR]

Spent coffee grounds (SCGs) constitute the main solid residue of the coffee brewing process. SCGs are generated in significant amounts daily, worldwide. The effective management of this waste through biological processes is still an unresolved problem. In this study, the application of hydrodynamic cavitation (HC) as a pre-treatment method for improving the biodegradability of SCGs suspended in municipal wastewater was proposed. An orifice plate with a conical concentric hole having inlet/outlet diameter of 3/10 mm was applied as the cavitation inducer. Three inlet pressures were chosen: 3, 5 and 7 bar. The effects in time intervals of 0, 5, 10, 20, 30 and 45 min were evaluated. The application of HC led to enhanced biodegradability for each case. The results of multi-criteria decision indicated that the most efficient combination in terms of biodegradability and energy usage was obtained at the pressure of 5 bar and duration of 20 or 30 min, depending on the adopted weights. The improvements of DOC/TOC (dissolved organic carbon/total organic carbon) ratio were 57% and 71%, as compared to the untreated samples. The release of caffeine was found at pressures of 5 and 7 bar. However, at 5 bar, this effect was noticed for the longest times, 30 and 45 min, respectively. [ABSTRACT FROM AUTHOR]

Purpose: The environmental impacts of the coffee industry are enormous, with large quantities of solid and liquid wastes generated globally. In the last years, measures have been implemented to valorize spent coffee grounds (SCGs) biowaste as a resource. The present study assessed the unexplored potential use of SCGs as a source of valuable humic substances (HS)-like materials, and linked their antioxidant properties to their chemical composition. Methods: Humic acid-like (HAL) and fulvic acid-like (FAL) were extracted from SCGs and characterized by elemental composition, UV-vis, FTIR, NMR and EPR spectroscopies. Their antioxidant capacity was determined in vitro through the ABTS decolorization assay and voltammetric techniques. Results: Elemental and spectroscopic characteristics were in the range of soil HS. Both HAL and FAL showed a high antioxidant capacity (2.29 ± 0.18 mmole− gHAL−1 and 3.63 ± 0.21 mmole− gFAL−1). The differences in the antioxidant and electrochemical responses of HAL and FAL are related to their chemical structure. Conclusion: The extraction of HS-like with remarkable antioxidant properties makes them a promising low-cost material to be upcycled in the agri-food system as natural fertilizer or novel antioxidants. Statement of Novelty: For the first time, we demonstrated the potential of spent coffee grounds to act as a low-cost source of humic-like substances with enhanced antioxidant capacity. [ABSTRACT FROM AUTHOR]

It is necessary to reduce dependency on fossil fuels for heating and waste generation, while also utilizing the energy potential of waste materials. One possibility is to create fuel pellets where waste makes up a small proportion so that the properties of the wood are not significantly altered with. This article investigates the energy usage of pellets containing spent coffee grounds (5 % or 10 %) and waste face masks (5 % or 10 %), with spruce sawdust as the primary input material (80 % or 90 %). The elemental, thermogravimetric, calorific value, mechanical durability, emission and performance characteristics, and ash melting temperatures of the pellets were evaluated during the experiment. The results were compared with respect to pure spruce sawdust pellets and the specified limit values for wood pellets in commercial and residential applications as specified in ISO 17225 [18]. Both tested samples met the element content limit (N, S, Cl, As, Cd, Cr, Cu, Pb, Hg, Ni, and Zn) for the highest quality grade (A1). No significant amounts of harmful elements were detected. The samples also complied with the limits of moisture content, ash content, and net calorific value (also known as lower calorific value). All samples met the emission limits in their respective classes (3, 4, or 5) according to STN EN 303-5+A1 [35]. However, the samples failed to meet the limit values for mechanical durability and ash melting temperatures. Despite this, the manufactured pellet samples represent a suitable fuel product for combustion purposes as a more sustainable thermal energy fuel.

Purpose: Globally, Colombia is recognized as a coffee-growing country par excellence, which entails generating a large amount of coffee waste. This narrative study aims to review the possible use of such coffee waste to obtain nutrient-rich compost following key composting processes. The final is to investigate the importance and suitability of this compost type. Method: The data collected for this study were from reviewing the scientific literature and research reports available in many reputable academic databases, i.e., Science Direct, Springer, PubMed, and Scopus. Reputable academic search engines like Google Scholar and ResearchGate were used to access relevant research and high-quality scientific documents. Results: The result revealed that using combinations of agro-industrial coffee waste when composted can be applied in agriculture because it provides wide-ranging nutrients, which can fertilize soil, accelerate plant growth, and even improve the nutrient content of vegetables. The SCGs used in agriculture prevent improper waste disposal by decreasing the pollution caused by the degradation of SCGs’ toxic components. Here we explore and review composting processes containing coffee waste. Conclusion: Employing coffee waste for compost implies benefits compared to landfills. The conversion of this coffee biomass waste into compost, and using it as a soil amendment, can reduce the waste volume, improve soil physico-chemical properties, enhance the nutrient use efficiency of crops, and correct the typical soil acidity of Colombian soils used for coffee production. Highlights · Colombia is recognized as the coffee-growing country par excellence. · The coffee agro-industry generates large quantities of solid waste. · Composting coffee biomass waste can act as soil amendment and enhances physico-chemical properties. · Composting is a highly effective remedy for environmental issues.

With growing concern over environmental sustainability and dwindling fossil resources, it is crucial to prioritise the development of alternative feedstocks to replace fossil resources. Spent coffee grounds (SCGs) are an environmental burden with an estimated six million tons being generated on a wet basis annually, globally. SCGs are rich in cellulose, lignin, protein, lipids, polyphenols and other bioactive compounds which are important raw materials for use in industries including pharmaceuticals and cosmetics. Furthermore, the energy sector has the potential to capitalize on the high calorific value of SCGs for biofuel and biogas production, offering a sustainable alternative to fossil fuels. SCGs are readily available, abundant, and cheap, however, SCGs are currently underutilized, and a significant amount are dumped into landfills. This review explores the potential of SCGs as a source of a value-added compound through various conversion technologies employed in the valorisation of SCGs into biochar, biofuel, and important chemical building blocks. The state-of-the-art, current knowledge, future research to stimulate the creation of sustainable products, and the challenges and economic feasibility of exploring SCGs in a biorefinery context are presented.

Abstract Biowaste-derived carbon materials are a sustainable, environmentally friendly, and cost-effective way to create valuable materials. Activated carbon can be a supporting material for electrocatalysts because of its large specific surface area and porosity. However, activated carbon has low catalytic activity and needs to be functionalized with heteroatoms, metals, and combinations to improve conductivity and catalytic activity. Ruthenium (Ru) catalysts have great potential to replace bench market catalysts in hydrogen evolution reaction (HER) applications due to their similar hydrogen bond strength and relatively lower price. This study reports on the synthesis and characterizations of carbon-supported Ru catalysts with large surface areas (~ 1171 m2 g−1) derived from coffee waste. The uniformly dispersed Ru nanoparticles on the porous carbon has excellent electrocatalytic activity and outperformed the commercial catalyst platinum on carbon (Pt/C) toward the HER. As-synthesized catalyst needed only 27 mV to reach a current density of 10 mA cm−2, 58.4 mV dec−1 Tafel slope, and excellent long-term stability. Considering these results, the Ru nanoparticles on coffee waste-derived porous carbon can be utilized as excellent material that can replace platinum-based catalysts for the HER and contribute to the development of eco-friendly and low-cost electrocatalyst materials.

Abstract This study determined the fertilizer potentials of the dehydrated food waste powder (DFWP) and spent coffee grounds (SCGs) through assessing their effects on yield, antioxidant activities, mineral and proximate compositions of leaf lettuce and Japanese hogfennel their efficiencies to inorganic fertilizers (N-P2O5-K2O, NPK). In this study, both organic amendments were applied at rates that supplied half, double and recommended nitrogen (N) requirements of the leaf lettuce (15 Mg N/ha) and Japanese hogfennel (10 Mg N/ha) established in Daejeon, South Korea. The recommended treatment of DFWP produced the highest lettuce and Japanese hogfennel yields, respectively. Halving the application rates of the organic amendments generally limited the yielding capacities while doubling them invoked negative yield responses in both crops. The highest antioxidant activities, mineral and proximate contents in both crops were obtained with the recommended dosage of amendments. The SCGs outperformed NPK in all the parameters of the Japanese hogfennel assessed in this study even though its impact on the leaf lettuce was adverse. Therefore, both DFWP and SCGs can effectively supply plant nutrients but their application rates should be regulated so as to avoid NaCl toxicity and elevated phytotoxicity in DFWP and SCGs, respectively.

The present study aims to investigate the catalytic effect of acid mine drainage (AMD) treated sludge based catalyst on the co-pyrolysis of spent coffee grounds and HDPE. The sludge was generated during the treatment of AMD using eggshell and hydrogen peroxide. Theromogravimetric analysis of pyrolysis of spent coffee grounds (SC), HDPE (High density polyethylene), blend of spent coffee grounds and HDPE (SC+HDPE) in the ratio of 1:1, and blended feedstock with sludge derived catalyst (SC+HDPE_AMDC) (1:1 wt. ratio) was conducted at various heating rates of 10 °C/min, 20 °C/min, 30 °C/min and 40 °C/min respectively. Iso-conversional models such as Ozawa Flynn Wall (OFW), Kissinger Akahira Sunose (KAS), Friedman, and Starink were utilized for the determination of activation energy (Ea) of the process. The results showed that using AMD treated sludge based catalyst to the pyrolysis process, enhances its overall efficacy by lowering the activation energy (Ea) (OFW- Ea: 209.11 to 177.14 KJ/mol, KAS-Ea: 208.30 to 173.06 KJ/mol, Friedman- Ea:210.54 to 176.28 KJ/mol, and Starink- Ea:208.60 to 173.44 KJ/mol). Criado's z-master plot (CZMP) method was utilized to analyze the mechanism of the reaction. The pre-exponential factor and thermodynamic parameters were also evaluated. It is concluded that the incorporation of sludge based catalyst (AMDC) lowered enthalpy and randomness of system. Catalytic co-pyrolysis requires less energy, making it more environmental friendly choice for the sustainable processing of biomass and plastics. The present investigation will aid in the design, optimization and scalability.

Spent coffee grounds (SCGs) contain abundant polysaccharides consisting of mannose (29 %), galactose (11 %), and glucose (11 %) and are a promising source of holocellulose nanofibers (HCNFs). In this study, the mannan-rich HCNFs were isolated from the SCG holocellulose in the yield of 52 % SCGs using an ultrahigh-pressure wet jet mill. The HCNF was refined by passing the suspension through a high-pressure homogenizer with a 95 μm nozzle 1–15 times. The 5-pass HCNFs were 2.4 nm wide and 0.7 μm long with 143 viscosity-average degrees of polymerization and contained mannan I crystals (5–10 nm in size) on cellulose microfibrils. The delignification process in water at 75 °C based on the Wise method allowed recrystallization of mannan on a cellulose microfibril substrate. The once-freeze-dried HCNFs had 30–50 nm widths and were not fully nanofibrillated in water when shaking the HCNF/water suspensions but exhibited comparable viscosities to those prepared by mechanical milling. The SCGs-derived HCNFs have a high potential for application in the food industry.

Coffee grounds are the most commonly generated daily waste in the world, raising numerous questions regarding their proper management and their environmental impact. The present study focuses on the physical and chemical characterization of oil extracted from spent coffee grounds (SCG), with the aim of valorizing this by‐product as a potential source for oil production. The results obtained from the analysis of SCG oil were also compared to those of some edible oils (soybean, corn, and sunflower oils) and cosmetic oils (lentisc, sweet almond, and castor oils). The results revealed that spent coffee waste yielded an important amount of oil, specifically 17.19%, as compared to corn (4.31%) and soybean (19.52%) seeds. Regarding the fatty acids composition of SCG oil, eight components were identified, with a high percentage of polyunsaturated fatty acids accounting for more than 45% of total fatty acids. The phytosterols composition of SCG oil revealed the presence of seven components, with β‐sitosterol being the predominant one. The tocopherol analysis showed that SCG oil contained only α and β isomers, with β‐tocopherol being the dominant form at over 68%. These findings accentuate the potential of spent coffee waste as a promising alternative for oil production and open up new applications for SCG oil, such as in the food industry, pharmaceutical applications, and cosmetics. Practical Application: Given the significant increase in the demand for vegetable oils, the oil industry has recently begun to explore new plant matrices, particularly those having low costs. SCG are the most commonly generated daily by‐product in the world. The present investigation aims to characterize and valorize the oil extracted from SCG. The obtained results revealed the potential of SCG as a promising alternative for oil production. Consequently, valorizing spent coffee waste as a natural by‐product for oil production can be an ideal solution to address numerous issues related to its proper management and its environmental impact. Hence, the oil industry can promote spent coffee waste, cheapest by‐products, as a promising alternative for oil production. Moreover, the present investigation represents a commendable model of the circular economy since the remaining waste obtained after extracting lipids from the coffee grounds waste can be used as natural fertilizer rich in protein for plant development. [ABSTRACT FROM AUTHOR]

Supercritical carbon dioxide (SCCO2) extraction was applied for recovering non-polar compounds in spent coffee grounds (SCGs) before enzymatic hydrolysis was performed. The SCCO2 extracted oil yield of 11.93 wt% was observed at 30 MPa and 50 °C. The detectable volatile compounds in SCGs oil were aldehydes and flavor compounds classified as furans. Although the degree of hydrolysis of SCGs and defatted SCGs (DFSCGs) were not significantly different, the soluble protein of DFSCGs was higher than that of SCGs. Electrophoretic profiles of SCGs and DFSCGs comprise polypeptide bands at < 20 and ~ 24 kDa, which are mainly derived from 11S globulin subunits. After hydrolysis, the molecular masses of 4–20 and 24 kDa were virtually eliminated, thus releasing polypeptides with molecular masses < 4 kDa. Furthermore, the DFSCGs hydrolysate had higher total phenolic content and antioxidant capacity than that of SCGs hydrolysate. Pretreatment of SCGs with SCCO2 enhances enzymatic accessibility, improves the quality of protein hydrolysate, and procures SCGs oil as a by-product. [ABSTRACT FROM AUTHOR]

Spent coffee grounds (SCG) are a type of food waste and are produced in abundance around the world. However, their utilization as a soil organic amendment is challenging due to their phytotoxic effect. In the present work, the impact of agronomic biofortification on Dutch cucumbers was investigated using different chemically modified SCG and analyzing their effects on iron contents, their capacity for releasing antioxidants, and the production of short-chain fatty acids after in vitro digestion–fermentation. The results indicated variations in the iron contents and chemical compositions of cucumbers according to the treatment groups. Functionalized and activated hydrochar from SCG increased Fe levels in cucumbers. Although activated hydrochar obtained at 160 °C and functionalized with Fe showed the highest iron supply per serving, differences in antioxidant capacity and short-chain fatty acid production were observed between the groups. It is concluded that growing conditions and the presence of iron may significantly influence the contribution of these cucumbers to the dietary intake of nutrients and antioxidants, which could have important implications for human health and nutrition. [ABSTRACT FROM AUTHOR]

Recently, colossal research interests have been paid in the scientific community to synthesize biomass-based polyols due to their availability, sustainability, and low toxicity. Here, in this work, the main objective involves an effective synthesis of eco-polyol from different types of spent coffee grounds biomass (Colombia Narino Supremo, Ethiopia Koke Honey Yirgacheffe G1 and mixed) through an acid-catalyzed liquefaction reaction by employing sulfuric acid and a mixed solvent of different types of polyether polyol and glycerol at a reasonable reaction temperature. Interestingly, Colombia Narino Supremo produced bio-polyol more qualitatively (1 phase) and quantitatively than the other types with the solvent mixture of GPX-600/glycerol. Consequently, the effect of experimental liquefaction conditions on the extent of biomass conversion was optimized by the design of experiments and statistical analysis using a 23-full-factorial design with temperature, time, and acid concentration as the process parameters. Also, the analysis of variance results with a 95% confidence level reveals that acid concentration (catalyst) is the most influencing factor on biomass conversion. However, the achieved maximum conversion was 65.3 wt% at 170 °C, 120 min, and 4 wt% of catalyst. The prepared polyol at the optimized condition showed an acid value of 18.6 mg KOH/g polyol, a hydroxyl value of 77.9 mg KOH/g polyol, and a viscosity of 348.2 cPs at 25 °C. Thus, this work demonstrates a substrate-specific promising approach to synthesize qualitatively and quantitatively bio-based liquid polyols using acid liquefaction at a reasonable temperature. [ABSTRACT FROM AUTHOR]

Biowaste-derived carbon materials are a sustainable, environmentally friendly, and cost-effective way to create valuable materials. Activated carbon can be a supporting material for electrocatalysts because of its large specific surface area and porosity. However, activated carbon has low catalytic activity and needs to be functionalized with heteroatoms, metals, and combinations to improve conductivity and catalytic activity. Ruthenium (Ru) catalysts have great potential to replace bench market catalysts in hydrogen evolution reaction (HER) applications due to their similar hydrogen bond strength and relatively lower price. This study reports on the synthesis and characterizations of carbon-supported Ru catalysts with large surface areas (~ 1171 m2 g−1) derived from coffee waste. The uniformly dispersed Ru nanoparticles on the porous carbon has excellent electrocatalytic activity and outperformed the commercial catalyst platinum on carbon (Pt/C) toward the HER. As-synthesized catalyst needed only 27 mV to reach a current density of 10 mA cm−2, 58.4 mV dec−1 Tafel slope, and excellent long-term stability. Considering these results, the Ru nanoparticles on coffee waste-derived porous carbon can be utilized as excellent material that can replace platinum-based catalysts for the HER and contribute to the development of eco-friendly and low-cost electrocatalyst materials. [ABSTRACT FROM AUTHOR]

In this study, we conducted the first plasticization of wheat flour (WF) with the addition of choline chloride:urea (1:5 molar ratio) eutectic mixture as a plasticizer and spent coffee grounds (cf) as a filler. Thermoplastic wheat flour (TPWF) films were obtained via twin-screw extrusion and then thermocompression. Their physicochemical characterization included mechanical tests, dynamic mechanical thermal analysis (DMTA), and sorption tests. XRD analysis revealed that the eutectic plasticizer led to a high degree of WF amorphization, which affected the physicochemical properties of TPWF. The results indicated that it was easy for the TPWF biocomposites to undergo thermocompression even with a high amount of the filler (20 pph per flour). The addition of the cf into TPWF led to an increase in tensile strength and a decrease in the swelling degree of the biocomposites. Biodegradation tests in soil revealed that the materials wholly degraded within 11 weeks. Moreover, a study of cultivated plants indicated that the biocomposites did not exhibit a toxic influence on the model rowing plant. [ABSTRACT FROM AUTHOR]