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Using biological/renewable resources as filler or modifier in both thermoplastics and rubbers has been of a great interest in order to reduce negative effects of traditional petroleum/natural gas based fillers. In this study, the main goal was the use of spent (waste) coffee grounds as a natural alternative filler to carbon black in acrylonitrile butadiene rubber (NBR) based compounds. Carbon black (CB) was partially replaced with fresh as well as spent coffee grounds (SCG) in NBR compound formulation. Stabilization effect of fresh coffee grounds was also investigated. Cure characteristics, physico‐mechanical, thermal, morphological, and dielectric properties of the bio‐based composites were tested and compared with the control (reference) compounds. Processability has been affected positively in the case of using coffee grounds thanks to the presence of triacyl groups in coffee. Up to 20% higher elongation at break values were measured when coffee is partially replaced with CB. Abrasion loss and oil resistance could be retained for coffee containing compounds. In conclusion, SCG were found to be a good natural alternative filler for bio‐based NBR composites without a significant change in material properties. Highlights: Spent coffee grounds ‐ a sustainable filler in bio‐based NBR compositesBoth fresh and spent coffee grounds are successful stabilizersPhysico‐mechanical, thermal, and dielectric properties are comparable [ABSTRACT FROM AUTHOR]

Gelatine hydrogels can be prepared using different cross-linking methods, such as enzymatic, physical or chemical. Unfortunately, in the case of chemical cross-linking, the typically utilized synthetic cross-linkers are harmful to human health and the environment. Therefore, in accordance with the principles of green chemistry and sustainable development, we have obtained compounds for the chemical cross-linking of hydrogel polymers from the processing of spent coffee grounds. In this study, gelatin/κ-carrageenan hydrogels are cross-linked using a bio-cross-linking agent from spent coffee grounds. Their physicochemical and thermal properties are compared with those of standard physical gels. The chemical cross-linking was confirmed based on FT-IR spectra, which demonstrated the formation of new covalent bonds between the oxidized polyphenols included in the extract from the spent coffee grounds and the amide groups present in the gelatine structure. Significant differences were also observed in morphology (SEM images) and other physico-chemical characteristics (gel fraction, swelling ability, hardness). The chemically cross-linked hydrogels in comparison to physically ones are characterized by a better developed porous network, a slightly higher gel fraction (64.03 ± 4.52% as compared to 68.15 ± 0.77%), and a lower swelling ratio (3820 ± 45% as compared to 1773 ± 35%), while TGA results show that they have better thermal stability. The research confirmed the possibility of using the developed natural cross-linking agent in the process of obtaining hydrogel materials based on bio-polymers. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effect of the proportion of coffee peel bokashi in the planting medium on the growth of papaya plant seedlings (Carica papaya L.) cv Calina. The research was conducted at the Faculty of Agriculture Screenhouse on Jalan Perjuangan, Cirebon City, at an altitude of 5 m above sea level. The research was conducted from May 2022 to June 2022. The experimental method used with a completely randomized design. The treatment consisted of 4 proportions of bokashi in the planting media, each of which was repeated 6 times so that there were 24 experimental units. Each experimental unit consisted of 10 polybags. The total papaya plant seeds used were 240 seeds. The treatments studied were: K0 = top soil, K1 = 250 g bokashi + 1 kg soil, K2 = 500 g bokashi + 1 kg soil, and K3 = 750 g bokashi + 1 kg soil. The results showed that the proportion of coffee peel waste bokashi significantly affected the growth of papaya plants. Using 500 g coffee skin waste bokashi in 1 kg of soil had the best effect on plant height, stem diameter, plant growth rate, number of leaves, root volume, root length, root ratio, and net assimilation rate. [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]

• Waste coffee pods (CP) were treated using a two-stage pyrolysis process. • A microwave-assisted pyrolysis process was employed for treating waste CP. • Catalytic reforming of evolved gas yielded 76 % (by volume) hydrogen at 900 °C. • Microwave and catalysis-assisted pyrolysis process can be a solution to upcycling. Plastic waste poses a critical environmental challenge for the world. The proliferation of waste plastic coffee pods exacerbates this issue. Traditional disposal methods such as incineration and landfills are environmentally unfriendly, necessitating the exploration of alternative management strategies. One promising avenue is the pyrolysis in-line reforming process, which converts plastic waste into hydrogen. However, traditional pyrolysis methods are costly due to inefficiencies and heat losses. To address this, for the first time, our study investigates the use of microwave to enhance the pyrolysis process. We explored microwave pyrolysis for polypropylene (PP), high-density polypropylene (HDPE), and waste coffee pods, with the latter primarily comprising polypropylene. Additionally, catalytic ex-situ pyrolysis of coffee pod pyrolysis over a nickel-based catalyst was investigated to convert the evolved gas into hydrogen. The single-stage microwave pyrolysis results revealed the highest gas yield at 500 °C for HDPE, and 41 % and 58 % (by mass) for waste coffee pods and polypropylene at 700 °C, respectively. Polypropylene exhibited the highest gaseous yield, suggesting its readiness for pyrolytic degradation. Waste coffee pods uniquely produced carbon dioxide and carbon monoxide gases because of the oxygen present in their structure. Catalytic reforming of evolved gas from waste coffee pods using a 5 % nickel loaded activated carbon catalyst, yielded 76 % (by volume) hydrogen at 900 °C. These observed results were supported by elemental balance analysis. These findings highlight that two-stage microwave and catalysis assisted pyrolysis could be a promising method for the efficient management of waste coffee pods, particularly for producing clean energy. [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]

Research efforts are focusing on investigating cost-effective and ecologically friendly ways to create nanoparticles as a result of promising developments in green technology (NPs). This experiment focused on the effectiveness of using biochar (TWB) made from coffee waste to extract levofloxacin (LEV) from water. The conclusive results of the trials showed that TWB is an effective adsorbent for removing LEV from liquid solutions. The TWB produced through biological processes underwent comprehensive analysis using techniques such as X-ray diffractometry (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller surface area measurement (BET), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. The bioengineered TWB's exceptional crystalline properties, which closely resemble the monoclinic structure of bulk TWB, were confirmed by the XRD analysis. Based on the scanning electron microscopy (SEM) data, the synthesis of TWB Nanoparticles resulted in the formation of spherical particles with an approximate diameter of 40 nm, accompanied by a substantial surface area of 285.55 m²/g. The Pseudo-Second-Order model, which best captured Levofloxacin's adsorption characteristics, was evaluated on the TWB, and the results showed that external mass transfer was the main determinant of response rate. It was also found that the adsorption process was endothermic and spontaneous. The system was optimized using the Box–Behnken design (BBD) methodology. The achieved removal capacity of 1119.19 mg/g utilizing the tested adsorbent was determined to be reasonable when compared to the performance of other previously used adsorbents when evaluating the effectiveness of eliminating LEV. The process of LEV adsorption onto TWB involves a number of different mechanisms, such as ion exchange, π-π interactions, electrostatic pore filling, and hydrogen bonding. Following extensive testing in connection with a real-world sample, the adsorbent demonstrated remarkable efficacy, and it maintained good performance even after undergoing three further regeneration cycles. By adjusting the annealing temperature, we controlled the synthesis of TWB nanoparticles across a range of sizes in order to maximize their antibacterial capabilities. This research utilized a pair of Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and a pair of Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli) to evaluate the antibacterial efficacy of TWB. Highlights: Green synthesis of biochar via using tea waste. Adsorption studies of harmful pesticides Levofloxacin (LEV). The adsorbents exhibited good reusability for four adsorption/desorption cycles. Adsorption fit with pseudo second order kinetics and Langmuir isotherm model. The adsorption fitted to pseudo-second-order kinetically. This system will provide helpful guidance for coloured effluent treatment. Optimized the results by using Box-Behnken design. [ABSTRACT FROM AUTHOR]

This study investigates using KOH-activated coffee grounds (KACGs) as an effective adsorbent for removing organophosphorus xenobiotics malathion and chlorpyrifos from water. Malathion and chlorpyrifos, widely used as pesticides, pose significant health risks due to their neurotoxic effects and environmental persistence. Spent coffee grounds, abundant biowaste from coffee production, are chemically activated with KOH to enhance their adsorptive capacity without thermal treatment. This offers a sustainable solution for biowaste management and water remediation. Adsorption kinetics indicating rapid initial adsorption with high affinity were observed, particularly for chlorpyrifos. Isotherm studies confirmed favorable adsorption conditions, with higher maximum adsorption capacities for chlorpyrifos compared to malathion (15.0 ± 0.1 mg g−1 for malathion and 22.3 ± 0.1 mg g−1 for chlorpyrifos), highlighting its potential in mitigating water pollution. Thermodynamic analysis suggested the adsorption process was spontaneous but with the opposite behavior for the investigated pesticides. Malathion interacts with KACGs via dipole–dipole and dispersion forces, while chlorpyrifos through π–π stacking with aromatic groups. The reduction in neurotoxic risks associated with pesticide exposure is also shown, indicating that no more toxic products were formed during the remediation. This research contributes to sustainable development goals by repurposing biowaste and addressing water pollution challenges through innovative adsorbent materials. [ABSTRACT FROM AUTHOR]

A Box–Behnken design (BBD) for a response surface methodology with five factors and three levels was applied to design 2,4-D degradation experiments under visible light. To optimize the experimental conditions, the five factors included the amount of Cdots in a Cdots (x%)-ZnBi2O4 catalyst (x = 0–2%), the decomposition time (90–120 min), the initial 2,4-D concentration (30–40 mg/L), the catalyst dosage (0.5–1.5 mg/L), and the pH (2–7), and these were selected as independent variables. The BBD method proposed a second-order polynomial equation that fitted the experimental data perfectly. The results of the analysis of variance (ANOVA) confirmed the appropriateness of the proposed model, resulting in the relationship between the predicted and adjusted values having an R2 value of 0.9980. The optimal conditions for the photodecomposition of 2,4-D were found to be an initial 2,4-D concentration of 30 mg/L, a degradation time of 120 min, a Cdots(2%)-ZnBi2O4 dosage of 1.0 mg/L, and a pH of 4.0. Under these conditions, the highest 2,4-D photodecomposition of 91.1% was obtained, which was in reasonable agreement with the predicted value of 91.67%. After 6 consecutive reaction cycles, the photodecomposition efficiency still exceeded 81%. The results confirmed that the Cdots(2%)-ZnBi2O4 photocatalyst has excellent reusability. Moreover, the lowest concentration of Cdots(2%)-ZnBi2O4 that inhibited the growth of E. coli (ATCC 8793) and S. aureus (ATCC 6538) was 150 µg/mL, with an inhibition zone of 18–19 nm for E coli and about 15 mm for S. aureus. [ABSTRACT FROM AUTHOR]

The scientific community's interest in finding an alternative to the term "wastes" for coffee by-products is steadily increasing. The substantial presence of polyphenols, caffeine, and tannins in these wastes could result in the contamination of water and soil, as they exhibit harmful effects on a range of plants, microorganisms, and aquatic organisms. However, these identical antioxidants can extensively be utilized in food packaging applications. In the context of active packaging, the development of bioactive food packaging films based on natural products and coffee industry wastes is of significant importance according to circular economy principles. In this study, the effect of coffee silverskin particles, i.e., waste of the coffee roasting process, and coffee silverskin aqueous extracts on the properties and antioxidant activity of wheat flour-based films with glucose for food packaging applications were evaluated. In addition, chemical structure identification, optical and morphological analysis, color measurements, and physico-chemical characterization of the films were performed, determining their water absorption, film solubility, and degree of swelling. Furthermore, the oxygen and water vapor transition rate and their antioxidant activity were also measured, and it was found that increasing the addition of coffee silverskin particles and aqueous extracts affected the properties of the films. The biocomposite films of wheat flour and glucose with coffee silverskin particles produced in this work exhibited higher tensile stress at break and Young's modulus compared with wheat flour film with no additives. However, a decrease in elongation at break was observed with increasing addition of the silverskin due to the transition from a pure elastomeric material to a crosslinked one following the formation of hydrogen bonds between the additive and the matrix, which was also found in the FTIR spectra. This work offers a new use of wheat flour and coffee silverskin as an inexpensive biocomposite material to produce multifunctional active films for food packaging applications. [ABSTRACT FROM AUTHOR]

In Colombia alone, 12.6 million bags of green coffee are produced, but at the same time, 784,000 tons of waste biomass are dumped in open fields, of which only 5% is recovered or used, and 10 million tonnes of coffee emit 28.6 million tonnes of CO2 eq annually. This presents a worrying dilemma, and the need to develop a technology to transform the waste into usable products is increasing. As a response to this, the valorization of coffee waste was explored through the production of biochar and platform chemicals by implementing a set of hydrothermal experiments with different biomass/water ratios (1:5, 1:10, 1:20, 1:40), particle sizes (0.5, 1, 2, 5 mm), stirring rates (5000 and 8000 rpm), and catalysts (H2SO4, NaHCO3 and CH3COOH) at 180, 220, and 260 °C in a batch reactor with autogenous pressure. Notably, the smaller B:W ratios of 1:20 and 1:40, as well as smaller particle sizes of 0.5 and 1 mm, yielded higher amounts of platform chemicals, while stirring showed minimal influence. CH3COOH significantly enhanced the process compared to other catalysts. The biochar was characterized as anthracite, and this obtaining of coal-like materials from biomass itself represents a remarkable feat. Said anthracite presented little to no variation in physical parameters, while catalysts induced functionalization. By optimizing factors like B:W ratio, particle size, and catalyst application, valuable insights have been gained into enhancing the yield of platform chemicals and quality of biochar from coffee waste. The findings not only contribute to sustainable waste management practices but also highlight the importance of exploring innovative solutions for utilizing agricultural by-products effectively. [ABSTRACT FROM AUTHOR]

Coffee is the second most traded commodity after petrol. The coffee industry produces about 23 million tonnes of waste every year. This implies that the unutilized portion of coffee carries a broad economic and environmental burden. The unutilized portion of coffee includes pulp, mucilage, parchment, husk, silver skin, and spent coffee grounds, each of which has its innate capacity to be reused for various industrial and domestic purposes. Coffee silverskin represents about 4.2% (w/w) of the coffee bean. Moreover, coffee silverskin contains phenolic compounds which have been studied extensively on account of their antioxidant properties. The main aim of the research is to convert coffee silver skin which is discarded as waste in coffee production, into a source of antioxidants that has wide application in the cosmetic and skincare industry. In this paper, conventional extraction methods for varying extraction temperatures (30–70°C), various solvents (n‐hexane, ethyl acetate, acetone, and ethanol) and extraction times (30, 60, and 90 min) were investigated to study their impact on the percentage of the coffee silverskin's antioxidant composition and the antioxidant property along with its total phenolic content (TPC) in coffee silverskin. It was found that ethanol was a suitable solvent and compared to the 50% ethanol‐water mixture, the 90% ethanol‐water mixture showed the highest extraction efficiency at the conditions of 70°C and 60 min for a TPC from coffee silverskin at 213 GAE mg/L. [ABSTRACT FROM AUTHOR]

Asphalt mixtures can include various recycled materials, which often replace some of the coarse and fine aggregate components. In some cases, a percentage of material called mineral filler, made up of particles that pass through a No. 200-sieve, is also admitted in the preparation of the mixture. With the increasing amount of packaging used as containers for various products, many of which need to be disposed of properly and become an environmental burden in warehouses without proper reuse, there is potential for including these elements in the sustainable modification of asphalt mixtures. This research suggests reusing plastic and aluminum coffee capsules, which are difficult to recycle. While most studies crush recycled materials to sizes smaller than 0.075 mm for use in mixes, this research focuses on assembling the waste capsules into a network of cells inside specimens subjected to bending to observe the mechanical behavior of the asphalt mixture. The findings indicate that incorporating capsule networks can lead to a significant enhancement in the flexural strength of the examined beams, with an increase of up to 200%. Moreover, the deformation is reduced by an average of 66% upon the emergence of the initial crack in the specimen. [ABSTRACT FROM AUTHOR]

Using coffee husks as waste material for bedding contributes to sustainable development. A sustainable choice of bedding has also, however, to be a safe choice for poultry. The study analysed immune-related gene expression in the intestinal mucosa and indicator bacteria in caecal content collected from broiler chickens bedded on material with coffee husk addition. One-day-old Ross 308 chickens were divided into four groups of 10 birds each in five replicates: C, the control group kept on wheat straw bedding; CH10, a group kept on bedding of 10% coffee husks and 90% wheat straw; CH25, a group kept on bedding of 25% husks and 75% straw; and CH50, a group kept on bedding of 50% husks and 50% straw. After 42 days, the birds were slaughtered, the caecal mucosae were removed for RNA isolation and the caecal content was collected for bacterial DNA isolation. The expression of genes involved in intestinal immune response and host organism defence and the relative abundance of indicator bacteria were analysed. Upregulation of the expression of genes related to the immune response and intestinal tightness was correlated with an increase in the percentage of coffee husks in the pellet. Coffee husk pellets at 50% bedding content caused a significant numerical increase in Bifidobacterium and a statistically significant increase in Lactobacillus. A significant reduction in E. coli bacteria was also demonstrated in this group. Coffee husk pellets at all content percentages resulted in a statistically significant diminution of the level of Streptococcus bacteria. The addition of coffee husks to poultry litter effects beneficial changes in the expression of genes related to intestinal health and the caecal bacterial profile. [ABSTRACT FROM AUTHOR]

The production of plastic products from non-renewable raw materials, such as petroleum, damages the environment. Consequently, biocomposites have aroused interest from industry and researchers due to their ecologically correct characteristics, mainly because they come from renewable sources. Therefore, this study aimed to produce biopolyethylene/coffee ground waste (BioPE/CGW) biocomposites and analyze the impact of CGW and polyethylene-graft-maleic anhydride (PE-g-MA) on BioPE. The biocomposites were prepared in a co-rotational twin-screw extruder equipped with a side feeder to feed the CGW. The materials were subsequently injection molded to produce the impact, tensile, and HDT samples. The temperature profiles used during extrusion and injection were between 170 and 180°C. The BioPE and biocomposites were investigated for the vibrational (Infrared Spectroscopy - FTIR), thermal (differential scanning calorimetry), mechanical (tensile, impact, and hardness), thermomechanical (heat deflection temperature (HDT) and Vicat softening temperature (VST)), and morphological (scanning electron microscopy (SEM)) properties. The compatibilizer improved the interface between phases, promoting mechanical and thermomechanical improvements in the biocomposites. PE-g-MA promoted increments in tensile strength and elastic modulus of up to 38% and 25% in the BioPE/CGW30 and an increase of 44% in the elastic modulus compared to BioPE. The thermomechanical investigations showed that HDT increased by 8.8 and 3.3°C and VST increased by 2.5 and 6.6°C compared to BioPE and the BioPE/CGW30, respectively. Biocomposites from renewable and biodegradable sources align with a sustainable development concept. [ABSTRACT FROM AUTHOR]

Adding organic soil amendments can improve the physical and hydrological properties of soil, subsequently enhancing fertility for better crop production. In this study, spent Arabica and Columbian coffee wastes and their respective biochars were evaluated as soil amendments to improve the physical and hydrological properties of loamy sand soil and enhance maize (Zea mays L.) crop growth. Spent Arabica coffee (AC) and Columbian coffee (CC) wastes were collected and transformed into biochar through pyrolysis process at 550 °C with a residence time of 3 h and pyrolysis rate of 5 °C per minute. The AC and CC derived biochar were termed as ABC and CBC, respectively. The produced soil amendments were applied to soil at 0% (control), 1%, 3%, and 5% in a column setup. The moisture characteristics, including water infiltration, evaporation, and water retention, were investigated. Thereafter, the prepared amendments were applied to loamy sand soils at 0% (control), 1%, 3%, and 5% (w/w) application rates. Maize growth was then observed for a period of 30 days under greenhouse conditions. Results of the column trials showed that ABC and CBC applied at 5% reduced the cumulative water evaporation by 57%–66% and cumulative infiltration by 124%–181% compared to control. Likewise, 5% application of ABC and CBC resulted in 101 to 130% higher water retention in loamy sand soil. Results of the greenhouse experiment showed that 5% application of ABC and CBC amendments resulted in root biomass of 2.12 and 2.38 g, respectively, as compared to 0.51 g in control treatment. Similar treatments resulted in shoot biomass of 9.70 and 9.93 g respectively, as compared to 7.37 g in control. Likewise, 5% application of CBC and ABC increase plant height from 15.71 to 30.94 cm in ABC and 33.23 cm in CBC. Overall, 5% application of coffee waste-derived biochars significantly reduced water evaporation and infiltration, while increasing soil water retention and maize plant height, root biomass, and shoot biomass. Therefore, spent coffee waste-derived biochar could effectively be employed to improve physical and hydrological properties of loamy sand soils for better crop productivity. [ABSTRACT FROM AUTHOR]

The development of eco-friendly elastomeric materials has become an important issue in recent years. In this work, thermoplastic elastomer samples of an ethylene–norbornene copolymer (EN) with coffee and tea biofillers mixed with typical fillers such as montmorillonite (MMT), silica (SiO2), and cellulose were investigated. The aim of this research was to determine the effect of fillers on the properties of the materials and to assess their degradability after two ultraviolet (UV) aging cycles (200, 400 h). The scientific novelty of this work is the assessment of the anti-aging effect of simultaneous biofillers–stabilizers based on coffee and tea waste. The surfaces of the obtained polymer compositions were examined using infrared spectroscopy (FTIR-ATR). Contact angles were determined, and surface energy was calculated. The mechanical properties were tested, and the influence of plant fillers and aging on the color change in the materials was analyzed. The combination of coffee with silica, MMT, and cellulose fillers limited the migration of fatty acids and other compounds from the biofiller to the EN surface (FTIR analysis). Based on the aging coefficients K, it was shown that all coffee- and tea-based fillers stabilized the polymer compositions during UV aging (400 h). The results allowed the authors to determine the importance and impact of waste plant fillers on the degradability of the synthetic EN. [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]

Global agricultural by‐products usually go to waste, especially in developing countries where agricultural products are usually exported as raw products. Such waste streams, once converted to "value‐added" products could be an additional source of revenue while simultaneously having positive impacts on the socio‐economic well‐being of local people. We highlight the utilization of thermochemical techniques to activate and convert agricultural waste streams such as rice and straw husk, coconut fiber, coffee wastes, and okara power wastes commonly found in the world into porous activated carbons and biofuels. Such activated carbons are suitable for various applications in environmental remediation, climate mitigation, energy storage, and conversions such as batteries and supercapacitors, in improving crop productivity and producing useful biofuels. [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]

Mulching cultivation with agricultural wastes is the main production pattern of coffee at present, but the effect of mulching cultivation on photosynthetic physiological processes of coffee plants is still not clear. Therefore, a randomized block design was adopted to establish a field experiment by one-year-old Coffee Canephora seedlings in this study. There were four types of mulch treatments, including non-mulch coffee waste (C), mulching coffee litter (L), mulching coffee cascara (cherry pericarp, P), and mulching coffee litter and cascara (LP) in this field experiment. Soil properties and microenvironment (e.g., moisture, temperature, pH, bulk density, organic matter content, alkali-hydrolyzed nitrogen content, available potassium content, and available potassium content), agronomic traits (e.g., specific leaf area, leaf area index, plant height, and relative chlorophyll content), and photosynthetic indices (e.g., photosynthesis, transpiration, respiration, stomatal conductance, intercellular CO2 concentration, water use efficiency, and carbon use efficiency) were investigated to determine the effects of different coffee waste mulches on the photosynthetic physiology of coffee seedlings. The results show that coffee litter and cascara mulch significantly reduced soil temperature by 0.42 or 0.33 °C, respectively, and coffee litter rather than cascara mulch significantly increased the soil's available potassium content by 46.28%, although coffee waste mulch did not affect other soil properties or microenvironment indices; coffee cascara mulching significantly increased the specific leaf area and net and gross photosynthesis of coffee by 45.46%, 78.33%, and 91.72%, respectively, but the mulching treatments did not affect stomatal conductance, transpiration, or carbon use efficiency in this study. Additionally, coffee cascara mulching increased leaf respiration and net and gross water use efficiency by 109.34%, 80.54%, and 104.95%, respectively. The coffee cascara mulching alone had the most significant positive impact on the photosynthetic index, followed by a combination of litter and cascara, litter alone, and the control treatment. The observed variations in the coffee photosynthetic index may be attributed to the reduction of soil temperature caused by mulching treatments rather than the increase in soil nutrients content. These results indicate that coffee cascara mulching could effectively promote photosynthesis and the growth of coffee seedlings by improving the soil microenvironment. [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]

Phenanthrene (PHE) is a polycyclic aromatic hydrocarbon categorized as a high priority organic pollutant being toxic for the ecosystem and human health, and its sorption on natural organic or inorganic substances seems a well-promising method for its removal from water streams. The goals of the present work are (i) to assess the capacity of low-cost adsorbents fabricated by treating coffee wastes and diatomaceous earth to remove PHE from water; (ii) to elucidate the role of the pore structure on PHE sorption dynamics; and (iii) to assess the potential to regenerate adsorbents loaded with PHE, by using the novel technology of cold atmospheric plasma (CAP). Diatomaceous earth (DE) and DE pre-treated with sodium hydroxide (NaOH) or phosphoric acid (H3PO4) were chosen as inorganic adsorbents. Coffee waste (CW) and activated carbons (AC) produced from its pyrolysis at 800 °C (CWAC), either untreated (CWAC-800) or pre-treated with NaOH (CWAC-NaOH-800) and H3PO4 (CWAC-H3PO4-800), were chosen as organic adsorbents. The adsorbents were characterized with nitrogen adsorption–desorption isotherms, attenuated total reflectance-Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and mercury intrusion porosimetry. Based on the PHE sorption capacity and pore structure/surface characteristics, the CWAC-NaOH-800 was chosen as the most efficient adsorbent for further equilibrium and kinetic sorption studies. The multi-compartment model was used to describe the PHE sorption dynamics in CWAC-NaOH-800 by accounting for the pore/surface diffusion and instantaneous sorption. The CWAC-NaOH-800 exhibited remarkable values for (i) the specific surface area (SBET = 676.5 m2/g) and meso- and micro-pore volume determined by nitrogen sorption (VLN2 = 0.415 cm3/g); (ii) the macro- and meso-pore volume determined by mercury intrusion porosimetry (VMIP = 3.134 cm3/g); and (iii) the maximum PHE sorption capacity (qmax = 142 mg/g). The percentage of adsorbent recovery after its regeneration with CAP was found to be ~ 35%. From the simulation of sorption dynamics, it was found that at early times, the sorption kinetics is governed by the film diffusion towards the external surface of grains, but at late times, most of the adsorbed mass is transferred primarily to meso-/macro-pores via diffusion, and secondarily to micro-porosity via surface diffusion. Based on the adsorbent characteristics, effect of pH on sorption efficiency, and numerical analysis of sorption dynamics, it was concluded that probably the dominant adsorption mechanism is the π-π interactions between hydrophobic PHE aromatic rings and CWAC-NaOH-800 graphene layers. The high PHE removal efficiency of CWAC-NaOH-800, the successful interpretation of sorption dynamics with the multi-compartment model, and the potential to regenerate PHE-loaded adsorbents with the green and economic technology of CAP motivate a strategy for testing CWACs towards the adsorption of other PAHs, application of adsorbents to real wastewaters, and scaling-up to pilot units. [ABSTRACT FROM AUTHOR]

This study evaluated the biochemical methane potential (BMP) of two types of spent coffee grounds (SCG) via anaerobic co-digestion with food waste. A domestic spent coffee ground (DSCG), from coffee infusion, and an industrial spent coffee ground (ISCG), from Brazil's soluble coffee producing industry, were used as substrates. The co-substrate of food waste was obtained from a restaurant and the sludge from an upflow anaerobic sludge blanket (UASB) reactor was used as inoculum. Triplicates of anaerobic batch reactors (250 mL) were fed with SCG in the proportions of 0%, 25%, 50%, 75%, and 100% of dry weight, using a substrate/inoculum ratio of 1. The BMP tests were performed for 45 days at a mesophilic temperature (35 ± 2 °C). The highest levels of BMP were detected with 25% DSCG (0.345 Nm3CH4/kgVS), 25% ISCG (0.351 Nm3CH4/kgVS), and with 75% of DSCG (0.301 Nm3CH4/kgVS). On the other hand, 75% of ISCG presented a low percentage of BMP (0.188 Nm3CH4/kgVS), due to inhibitor compounds release as the percentage of added SCG increased. Results indicate that either domestic or industrial SCG has the potential for energy recovery via anaerobic digestion (AD). Therefore, AD is a promising alternative for SCG valorization. [ABSTRACT FROM AUTHOR]

This review article focuses on the application of microwave-assisted techniques in various processes, including microwave-assisted extraction, microwave-assisted pyrolysis, microwave-assisted acid hydrolysis, microwave-assisted organosolv, and microwave-assisted hydrothermal pretreatment. This article discusses the mechanisms behind these techniques and their potential for increasing yield, producing more selectivity, and lowering reaction times while reducing energy usage. It also highlights the advantages and disadvantages of each process and emphasizes the need for further research to scale the processes and optimize conditions for industrial applications. A specific case study is presented on the pretreatment of coffee waste, demonstrating how the choice of microwave-assisted processes can lead to different by-products depending on the initial composition of the biomass. [ABSTRACT FROM AUTHOR]

Liquid digestate can be used to provide nutrients for microalgae cultivation but the medium needs to be clear and colorless. The aim of this work was to use liquid digestate from coffee waste biomass to produce a light-permeable medium for microalgae cultivation. A boron-doped diamond anode was applied for electrochemical decolorization of the digestate. The electrochemical oxidation process reduced the platinum-cobalt color value by up to 97% and the chemical oxygen demand by 84.1%. After electrochemical oxidation, 87.4% of the ammonium nitrogen (NH4-N) was retained. Decolorization of the spent coffee grounds liquid digestate was compared with that of dairy cow manure liquid digestate. It took 90 min longer to fully decolorize the spent coffee grounds liquid digestate compared with the dairy cow manure liquid digestate. The boron-doped diamond anode performed better in the decolorization than Ti/IrO2 and Ti/Pt anodes. The effects of the initial Fe2+ concentration and current on the electrochemical oxidation process were also evaluated. Increasing the initial Fe2+ concentration enhanced the Fenton reaction and chemical oxygen demand removal. A higher current enhanced the electrochemical decolorization process and side reactions. Electrochemical oxidation using a boron-doped diamond anode is a promising method for producing an appropriate medium for microalgae cultivation because it promotes decolorization of liquid digestate and retains most of the NH4-N. [ABSTRACT FROM AUTHOR]

In this study, we introduce a straightforward and effective approach to produce P-doped hard carbon using coffee grounds as the precursor, with H3PO4 serving as the doping agent. By varying the concentrations of H3PO4 (1 M, 2 M, and 3 M), we aimed to determine the optimal doping level for maximizing the incorporation of phosphorus ions into the carbon framework. Our investigation revealed that using 2 M of H3PO4 as the dopant material for hard carbon led to promising electrochemical performance when employed as an anode material for sodium-ion batteries. The P-doped hard carbon, carbonized at 1300 °C, exhibited an impressive reversible capacity of 341 mAh g−1 at a current density of 20 mA g−1, with an initial Coulombic efficiency (ICE) of 83 %. This outstanding electrochemical performance of P-doped hard carbon can be attributed to its unique properties, including a porous agglomerated structure, a significant interlayer spacing, and the formation of C–P bonds.

Response Surface Methodology (RSM) has been widely employed for optimizing processes. However, the implementation of RSM in sensory studies is still limited. Moreover, most publications implementing RSM on sensory disregarded the validation stage as normally applied for process optimization. In this study, validating sensory overall acceptability with RSM was proposed by the Just-About-Right (JAR) technique. Coffee-leaf tea has great commercial potential as an ethnic beverage with unique sensory attributes but is still underutilized. Optimizing sensory acceptability level by modifying temperature and duration of brewing using the RSM was expected to obtain well-accepted coffee-leaf tea. Robusta coffee leaf tea is brewed using combined Decoction - V60, French Press, combined French Press - V60, and V60 at 90oC to 100oC for 2 to 10 minutes. Evaluated by 110 untrained panelists, it was observed that the ideal brewing parameters for each technique were 96.6oC for 6.5 minutes for Decoction – V60, 96oC and 6.5 minutes for French Press, 90oC and 2 minutes for French Press - V60, and 90oC and 2 minutes for V60. All optimum brewing conditions based on RSM were successfully validated by overall acceptability on JAR (p-value 0.05). Thus, the JAR technique can enhance the overall sensory acceptability analysis and optimization.

The primary goal of the current research was predicting the optimum operational parameters for removing of Fe (II) from aqueous solutions by Exhausted Coffee Husk (ECH) biochar, through batch mode experiments using a Box-Behnken Design (BBD) within a Response Surface Methodology (RSM) framework. The effect operational factors for instance, pH, contact time and the dosage of ECH-biochar were investigated in a certain range, prior to conducting the BBD experiments. The pH was in a range of 4–9, while the contact time was in between 30 and 150 minutes and the dosage 0.05–2.5 g. The results showed that the optimum operational parameters for ECH biochar as biosorbent for Fe ions removal were 7, 0.102 g, 54.49 minutes for pH, contact time and dosage, respectively, with the RE and biosorption capacity (qt) were 99.91 % and 73.09 mg/g. The validation test showed the similar results were obtained for RE and qt with %RSD were 0.7 %. The process of Fe biosorption corresponds effectively with a modified Langmuir isotherm model, and the prediction of the rate constant is reliably achieved using the pseudo-second-order kinetic model. Furthermore, analyses of scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) and X-ray diffraction (XRD) showed ion exchange as the Fe removal mechanism by the ECH-BC, while Fourier-transform infrared spectroscopy (FT-IR) also showed the role of structural alterations on the surface of ECH-BC subsequent to the biosorption of Fe.

The aim of this study was to develop a photothermal material modified with carbonization and ZnCl2 impregnation and supported by polyvinyl alcohol (PVA) for water purification using the waste coffee grounds. Scanning electron microscopy (SEM) characterization of the prepared material revealed that a significant surface modification was achieved due to the carbonization and ZnCl2 impregnation. X-ray diffraction analysis (XRD) pattern of the samples showed two broad peaks at 18.4° and 22.2°, this is due to the crystal planes of β-crystal phase structure, which indicates the existence of strong hydrogen bonds between the micro-structures and therefore less suspectable to chemical attack. Additionally, thermogravimetric analysis (TGA) result suggests a slight mass reduction between the temperature range of 65–75 °C implying the thermal stability of the prepared material. The produced modified material had a photothermal conversion efficiency of 74% and could produce vapor at a rate of 1.12 kg/m2h under 980 W/m2 irradiation at 1 sun. A significant reduction in Cu2+ ion concentration (83%), turbidity (91%), total dissolved solids (TDS) (61%), microbial load (95.6%), and total hardness (41.2%) were achieved. Therefore, waste coffee grounds can be considered as a future eco-friendly and low-cost candidate for water purification. [ABSTRACT FROM AUTHOR]

Coffee, one of the most popular beverages worldwide, generates significant waste during production, including coffee husk. Annually, an estimated 10 million tons of coffee husk waste are produced globally as a by-product of the coffee industry. Improper disposal of coffee husk waste presents environmental risks and challenges to human health. Handling and processing this material can lead to pollution, while improperly discarded waste may attract pests and release pollutants, necessitating proper management strategies. This review highlights the economic, social, and environmental advantages of sustainably converting coffee husk waste into valuable by-products. It particularly focuses on recent advancements and innovative applications in coffee husk utilization. The review elucidates the detrimental environmental impacts of coffee husk waste and underscores the imperative for sustainable utilization. Notably, it delves into the adaptability of coffee husks as a bio sorbent for environmental remediation, a constituent in building materials, a renewable energy source, and a component in pharmaceutical and food applications. Emphasizing the relevance of supporting sustainable practices, the review advocates for capitalizing on the latent potential of coffee husk waste and transforming it into useful resources. Overall, this review suggests the adoption of sustainable practices and emphasizes the transformational potential of coffee husk waste in addressing environmental challenges and promoting resource efficiency. [ABSTRACT FROM AUTHOR]

Soil acidity poses a challenge to crop production by limiting the availability of nutrients for plants. The aim of this study was to assess the efficacy of a natural waste-based fertilizer composed of Mytilus chilensis seashells, coffee bean wastes, banana peels, and wood ashes on lettuce growth and physiological quality. The seashells were used with organic matter (W-OM), without organic matter (Wo-OM), and a mixture of equal parts of W-OM and Wo-OM (50:50). The coffee bean wastes, banana peels, and wood ashes were used as ingredients. The soil pH, chlorophyll index in the lettuce leaves, and nitrogen level (in the soil and leaf) were measured for a period of 66 days. Vitamin C content in the harvested leaves was measured. The W-OM fertilizer allowed for an increase the soil pH from less than 6.5 to 7.0±0.5. The nitrogen provided by the coffee bean waste was partially available to the plant root, which decreased the chlorophyll index in the lettuce leaves. The studied fertilizer (W-OM, Wo-OM, and 50:50) allowed to increase of vitamin C content in the lettuce leaves. In conclusion, the natural waste-based fertilizer showed a promising effect in alleviating soil acidity and enhancing the nutritional quality of lettuce plants. [ABSTRACT FROM AUTHOR]

The growing global consumption of coffee has positioned Colombia as the third largest producer worldwide. However, the processing of coffee beans generates significant by-products, such as mucilage, which is rich in phenolic compounds with antioxidant activity. Inadequate disposal of this waste creates environmental problems and economic losses. This research aimed to develop high-quality coffee mucilage capsules using spray drying technology. Chemically modified banana starch with octenyl succinic anhydride (OSA) and commercial maltodextrin were used as coating materials to enhance the properties of the capsules. Physicochemical and functional characterization was performed on samples of fresh and filtered coffee mucilage (MF), concentrated mucilage (MC), concentrated mucilage with the addition of maltodextrin and OSA-modified starch (MCMA), and finally, spray-dried coffee mucilage powder (MP). The antioxidant capacity (AC) of the mucilage was evaluated throughout the processing stages. MF showed an AC of 179.2 μmol of trolox/100 g, while the final coffee mucilage powder (MP) showed a significantly higher AC of 5444.35 μmol of trolox/100 g. Additionally, the MP showed a stability index of 0.48, water activity (aw) of 0.19, solubility of 14.64%, and a high water retention capacity of 90.53%. Microscopic analysis revealed amorphous structures with an average size of 29.16 ± 2.12 μm in the MP. These findings highlight the potential of spray drying with food-grade matrices such as OSA-modified banana starch to encapsulate coffee mucilage, preserving its antioxidant capacity and creating a new functional food ingredient with water retention properties. [ABSTRACT FROM AUTHOR]

Aims: Coffee silverskin (CS) is the most abundant waste from coffee roasting. In this research, the potential of CS as soil fertilizer for barley (Hordeum vulgare L.) cultivation was evaluated. Methods: Barley plants were grown, for 10 days from the start of germination, in soils mixed with different CS percentages (0, 2, 6 or 10%). The effects of CS addition on soil capacity to retain water and on the mold/yeast community were evaluated. Physio-morphological and biochemical responses of leaves and roots of barley plants growing in CS-enriched soil were evaluated. Results: Root and shoot length decreased in plants grown with CS, but biomass was less affected and even increased at 2% CS. Photosynthesis was higher in barley seedlings grown on CS-enriched soil than in control plants. However, Chl b was reduced in leaves of plants grown with CS. The total leaf protein content did not change with moderate CS additions in soil. However, when grown in soil with 10% CS, a significant reduction of total protein and Rubisco was observed. Extracts of barley shoots from plants grown in soil with 10% CS showed a greater antioxidant capacity with respect to all other experimental conditions. Conclusions: We conclude that CS addition to soil may improve soil property to retain water and, at low concentrations (2% w/w) positively affects barley physiology and growth. [ABSTRACT FROM AUTHOR]

In this work, coffee silverskin (CSS) fibers were subjected to alkali pretreatment (ALK‐CSS) and alkali pretreatment, followed by a 4‐bar steam explosion process (SEW4). Both treated fibers presented a higher degree of crystallinity, enhanced thermal resistance and also cleaner, rough, and defibrillated surface due to the removal of noncellulosic components, as was shown in scanning electron microscopy, thermogravimetric analysis, Fourier‐transform infrared spectra, and x‐ray diffraction (XRD) results. The SEW4 fibers were incorporated into the poly(butylene adipate‐co‐terephthalate) (PBAT) matrix in contents up to 5% wt. through melt processing. PBAT/SEW4 composites were evaluated by their microstructure, thermal properties, degree of crystallinity, and hydrophilic behavior. XRD results showed PBAT/SEW4 composites with higher degrees of crystallinity and contact angle tests revealed increased composite hydrophobicity with the increase of SEW4 content in the PBAT matrix. This work describes the importance of recovering coffee lignocellulosic waste and producing value‐added by‐products, especially in packaging manufacturing. [ABSTRACT FROM AUTHOR]

Extraction of natural compounds generally uses organic solvents, which have a high risk to human health. Green solvents based on the natural deep eutectic solvents (NADES) have been used for the extraction of active compounds from coffee cherry waste. This research has formulated eight NADES based on choline chloride by combining fructose, citric acid, glycerol, proline, glucose, xylose, propylene glycol, and lactic acid with a mole ratio of 1:2. The FTIR analysis of NADES showed that there was a hydrogen bond interaction with OH group peaks in the wave number range 3012-3357 cm-1. NADES application was used for phenolic and tannin extraction from coffee cherry waste. The extraction efficiency of phenolic was combined of choline chloride with HBD of proline>xylose>glucose>glycerol>lactic acid >fructose>propylene glycol>citric acid. The maximum phenolic content in the extract using choline chloride-proline was 11.81 mg GAE/g. The ability of NADES to extract tannins using choline chloride with the combination of glucose>proline>lactic acid>propylene glycol>glycerol>citric acid> fructose. The maximum tannin content was obtained at 1.58% using NADES based on choline chloride with glucose. NADES has been successfully used as an environmentally friendly to replace organic solvents to extract phenolic and tannin in coffee cherry waste. [ABSTRACT FROM AUTHOR]

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]

Synthesis of nanoscale materials is urgent with an increasing demand due to their valuable applications in various industries including medicine and aerospace. To advance green and sustainable nanomaterial synthesis, this study employed liquid-phase exfoliation techniques using bath sonication with gallnut and coffee waste as plant extracts to develop two-dimensional (2D) nanomaterials: functionalized few-layer graphene (FFG), h-boron nitride nanosheets (BNNs), functionalized few-layer borophene (FFB), and MXenes, from graphite, h-boron nitride, boron, and HF-etched Ti3AlC2, respectively, as well as their hybrids BNN/FFG, BNN/FFB, FFG/MXene, BNN/MXene, FFG/FFB, and FFB/MXene. When incorporated at 1 wt%, these nanomaterials and nanohybrids significantly improved both the mechanical properties and thermal stability of polyvinyl alcohol (PVA) and chitosan films. Specifically, the resulting hybrid nanocomposite films outperformed pure PVA in terms of tensile strength (35.1 ± 0.6 MPa) and Young's modulus (862.4 ± 42.4 MPa) with a 3.25- and 6.5-fold increase, respectively. In addition, the reinforcement of nanomaterials into the films increased the initial decomposition temperatures up to 50%. Furthermore, utilizing the graphene production process, we performed a life cycle assessment of this technology focusing on three impact categories: energy use, biogenicity, and land transformation. Commercial exfoliating solvents are much more costly than our plant extracts, according to an economic analysis of the costs related to the use of plant and coffee waste extracts in comparison to other exfoliating solvents. To date, this is the first study to successfully synthesize FFB, MXenes, and their hybrids with FFG and BNN using gallnut or coffee extract-mediated liquid phase exfoliation. The established method of nanohybrid preparation provides a simple, energy-efficient, and environmentally friendly approach that can be adapted for the design and synthesis of a wide range of functional hybrid nanomaterials with diverse applications. [ABSTRACT FROM AUTHOR]

Using a simple, low cost, and excellent efficient approach, carbon dots (CDs) were fabricated via a one-pot hydrothermal process of coffee waste. Amazingly, the combination of 2% CDs with ZnBi2O4 to form a new and excellent heterogeneous photocatalyst enabled the complete decomposition of 2, 4-dichlorophenoxyacetic acid (2, 4-D) into CO2 and H2O. The findings of this study provide a new perspective on the utilization of agricultural waste for creating products of scientific and practical significance. More than 91% of 2, 4-D (initial concentration of 30 mg/L) was completely decomposed and dechlorinated using 1.0 g/L of CDs (2%)-ZnBi2O4 at pH 4.0 after 120 min of exposure to visible light (with k = 0.0178 min−1), and more than 86% of the decomposed 2, 4-D was mineralized into CO2 and H2O. There was no sign of catalyst deactivation after four cycles of reuse, demonstrating the durability and efficiency of CDs (2%)-ZnBi2O4. The significant improvement in the photocatalytic efficiency of CDs (2%)-ZnBi2O4 compared with that of bare CDs or ZnBi2O4 is due to the formation of defects at the interfaces of the heterojunction; therefore, the movement of photogenerated electrons at the interface between the two components is rapid. The mineralization of 2, 4-D by CDs (2%)-ZnBi2O4 upon exposure to visible light is induced mainly by the photogenerated holes, followed by O2•−, and finally OH• radicals. [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]

This study examined the utilization of spent coffee grounds with different aqueous extraction methods for the bioelectricity generation from coastal benthic sediment through a sediment microbial fuel cell (SMFC) system. Different methods for the aqueous extraction of SCGs were evaluated, including rinsing and drying of the SCG (SMFC-CRD), immersion, rinsing and drying (SMFC-CRID), drying alone (SMFC-CD), and untreated SCG (SMFC-C). The caffeine concentration in the SCG was significantly reduced using pretreatments, with SMFC-CRID achieving the lowest concentration of 0.021 ± 0.001 mg/g. SMFC-CRD contributed to the generation of the highest current density of 213.7 mA/m2 during closed-circuit operation and exhibited the highest power density of 96.9 mW/m2 in the polarization test, due to the suitable caffeine content of 0.275 ± 0.001 mg/g in the SCG. This study could provide a cost-effective method for reusing SCGs (i.e., 128 g) while generating bioelectricity as an alternative energy source. These results suggest that pretreatment with SCGs is essential for achieving optimal power density and reducing the caffeine concentration in the SMFC system. [ABSTRACT FROM AUTHOR]

Elevated concentrations of nitrate (NO3−) and nitrite (NO2−) are possibly the most widespread contaminant in groundwater, contributing to eutrophication. However, it is also a potential nutrient which can be recovered. The present work evaluates and optimizes the removal efficiency of NO3− and NO2 using acid-modified waste coffee grounds biochar (ACGB) in aqueous solution. Central composite design (CCD) was adopted to optimize the independent variables (acid molarity, heating temperature, and storage time) influencing the removal of NO3− and NO2−. The ANOVA analysis of the CCD suggested all the independent operating parameters had significant (p value < 0.05) impacts in the removal efficiency of NO3− and NO2− by the ACGB. The results exhibited optimal removal efficiencies of 83.8% and 73.3% for NO3− and NO2−, respectively, using the modification conditions of 0.8 M HCl, at 150 °C for 60 min. This work highlights removal of NO3− and NO2− onto an organic chemical free adsorbent. Point zero charge of ACGB presumes that electrostatic attraction of the positively charged surface of ACGB has mainly contributed to removal process via adsorption. However, adjustment of pH to alkaline condition negatively impacts the removal efficiencies of NO3− and NO2− which decreased to less than 50%. The spent nitrogen enriched, ACGB has high potential to be converted into soil fertilizer. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Biomass-derived activated carbons (ACs) are garnering significant attention as promising adsorbents for gas adsorption. Currently, potassium hydroxide (KOH), which is severely harmful to the environment, is mostly used for the activation process. Recently, potassium oxalate (K2C2O4) has emerged as an alternative reagent, because it is more environmentally benign and exhibits an activation mechanism similar to that of KOH. In this study, we successfully prepared ACs using coffee grounds and K2C2O4 as a biomass precursor and an activating reagent, respectively. The specific surface areas of the coffee ground-derived AC (CACX, X denotes the ratios of K2C2O4 and coffee grounds) increased up to 2156 m2 g−1 in CAC4 and then decreased in CAC5. Interestingly, the highest CO2 adsorption capacity was shown by CAC3 because of its highest microporosity (∼83%). This reveals that certain micropores of <0.73 nm led to an efficient CO2 adsorption at 273 K (6.91 mmol g−1), while the broader micropore range of <1.1 nm resulted in the highest capacity of 5.49 mmol g−1 at 298 K. Moreover, we found that the experimental data (R2 > 0.99) were best fit by the pseudo first-order polynomial at all temperatures (303, 313, and 323 K), indicating that physical adsorption is dominant in these systems. Further, a CO2 adsorption–desorption of 10 cycles under flue gas conditions (15% CO2/85% N2 at 313 K) demonstrated an energy-efficient regeneration. Therefore, the results of this study suggest that ACs hold the potential for exhibiting a high CO2 capture performance with the benefits of eco-friendliness, energy efficiency, and mass production. [ABSTRACT FROM AUTHOR]

The recent developments of urban areas change the climate in the ecosystem and decreasing the arable land became the pressurized problems for all the producers of the present world. Moreover organic agriculture optimizes the application of biocomposts to improve soil fertility and productivity while minimizing the environmental implications and also it is necessary for sustainable agriculture. The study was conducted at St Josephs College for Women (A), Visakhapatnam Andhra Pradesh. Agro-industrial wastes of Paddy and Coffee husk were collected and were used for the biocomposting process using Pleurotus eous, P. florida, Trichoderma asperelloides and Eisenia fetida. The vermicompost was used for the growth of black gram with 6 treatments. The plant was analyzed for root length, shoot length, number of leaves, number of nodules, fresh weight and dry weight at different stages (20, 40 and 60 DAS). On 90th day the yield parameters like number of pods/plant, number of seeds/plant, length of the pod, weight of the seeds/pod, fresh weight and dry weight of the pod were analyzed. The experimental study results revealed that the treatment 6 (Pre decomposed Coffee husk, Consortium of Pleurotus eous, P. florida, Trichoderma asperelloides and Eisenia fetida) has shown a significant increase in root length (7.9,12.2 and 16.5 cm), shoot length (11.8, 25.8 and 30.7 cm), number of leaves(19.0,37.0 and 41.0) number of nodules (10.0,30.0 and 17.0), fresh weight (2.77,7.37 and 15.39 g) and dry weight (0.52,3.67 and 5.73 g) of the plant on 20 DAS, 40 DAS and 60 DAS and the yield parameters also showed the increase in number of pods/plant (39), number of seeds/plant (5), length of the pod (5.6 cm), weight of the seeds/pod (2.384 g), fresh weight of the pod (2.95 g) and dry weight (1.195 g) on 90th Day of black gram when in comparison with the control. It is to conclude that treatment 6 can be a better manure to enhance the growth and yield of plants and also it can be a great help for the farmers. [ABSTRACT FROM AUTHOR]