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Despite the variety of technologies available for the valorization of biowaste, this fraction of municipal solid waste is usually disposed of in landfills and dumpsites in undeveloped and developing countries. The selection of technological strategies compatible with the reality of each location represents an essential role in the success and continuity of the operation of the facilities. The best strategy will result from combining different environmental, economic, social, and technical dimensions, confronted with the interests of the stakeholders and the legal and policy contexts. Due to the complexity of different criteria, alternatives, and interests, a Multi-criteria Decision-making (MCDM) methodology is recommended to ensure the quality of the decision-making process. This study presents a systematic review of publications that have applied multi-criteria analysis as a decision support tool for the selection of biowaste management strategies. The different stages of management are discussed separately, highlighting the change in paradigms over time. It was found that less than a hundred studies have addressed it so far, with Asia contributing to most publications. However, the timeline shows that the number of publications is increasing, with multi-criteria models representing great potential to support decisions at any individual management stage, from preventing food waste to using by-products. Integrated multi-criteria approach that combines all stages of biowaste management, however, is still scarce in the literature. [ABSTRACT FROM AUTHOR]

Aim Methods Results Conclusion Composts made from food waste will soon become more widespread on the market thanks to the upcoming enforcement of the legal obligation to sort biowaste. Our experiment aims at improving knowledge on the short‐term effects of these composts on soils’ physicochemical properties and vegetable crops.Three composts with contrasting characteristics were tested: a 100% v/v green waste compost (C1), and two composts composed of 50% v/v food waste and 50% v/v green waste, one prepared directly on the soil (C2) and the other from a competing producer who have the French NFU 44‐051 (AFNOR NF U 44‐051, 2006) certification for an organic amendment (C3). They were applied at a rate of 100 t ha−1 (dry matter) on two cropped soils with contrasting textures. Soil‐and‐compost mixes and compost‐free soil were planted with lettuce, radish, and potato.Seventy‐four days after planting, composts improved some soil physicochemical properties. The compost‐amended soils had better saturated hydraulic conductivity (Ks, 1 10−3–2.5 10−3 cm s−1) than the compost‐free soil (0.5 10−3 cm s−1), and water‐stable aggregates were higher than the initial value in C3 soil, equal to it in C2 soil, and lower in C1 soil. pH, total nitrogen, and organic carbon increased in all compost‐amended soils. Food waste compost stimulated crop production. The yields (dry matter) of all three crops were two to three times higher in the two soils amended with food waste compost compared to unamended soil, whereas they decreased almost two times in the soil amended with green waste compost due to nitrogen immobilization. Trace metals (particularly Pb and Cd) added by the composts, although present in edible parts of the plants, did not exceed the European rules for trace metals.Thus, food waste composts have positive effects on soils and vegetable crops, and the higher their organic matter content, the higher these positive effects. [ABSTRACT FROM AUTHOR]

AbstractIn this work, the biowaste of Musa paradisiaca (Banana) was used for removing contaminants from water by adsorption on a batch scale using Congo red (CR) dye as a test case. Although banana peel adsorbents have been the subject of much research for a range of applications, including the removal of colors from wastewater, our study differs from others in that we treated the banana peel adsorbent with hydrogen peroxide (H2O2), which significantly enhanced its performance when compared to untreated banana peel powder. By eliminating organic contaminants, discoloring the sample, inhibiting the growth of bacteria or fungi, and raising the quantity of active sites accessible for dye adsorption, the H2O2 treatment increases efficiency. The results indicated that optimal conditions for CR dye removal with physio-chemically processed Musa paradisiaca biowaste were: pH 3, adsorbent dose 0.4 g, temperature 30 °C, and contact time 25 min. Equilibrium data were evaluated with isothermal and kinetic models, indicating that the data followed second-order kinetics with a correlation coefficient of R2 = 0.995 with a maximum dye removal of 8.577 mg/g. Furthermore, the study found that CR dye removal was physiochemical and exothermic process, as confirmed by the experimental data, with a ΔGo of −6.992 kJ/mol. The results of this study suggest that this fabricated material of Musa paradisiaca biowaste could be a potential alternative for large-scale Congo red dye elimination from industrial effluents. This is both a sustainable and cost-effective solution. [ABSTRACT FROM AUTHOR]

Citrus fruits are widely grown, processed, and distributed in more than 140 countries, with annual global production exceeding 124.3 million metric tons. This substantial consumption generates significant organic waste, accounting for approximately 50–60% of the total fruit mass, primarily in the form of peel, pulp, and seeds. Often discarded or reused as animal feed, these wastes contribute to significant environmental pollution and economic losses. Therefore, the valorization of these by-products represents an important opportunity to mitigate these challenges and improve the sustainability of the Citrus-related industry. This review highlights Citrus seed waste concerning its invaluable bioactive compounds, including fatty acids, phenolic compounds, limonoids, dietary fibers, vitamins, and carotenoids. Chemical compositions of Citrus seed biowaste differ depending on a variety of factors, such as Citrus variety, fruit maturity, environmental conditions, waste storage conditions, and extraction methods. The extraction and purification of phytochemicals from Citrus seed biowaste are one of the major procedures for valorizing waste. The two types of effective extraction methods are traditional (conventional extraction) and innovative (green extraction). Furthermore, Citrus seeds have been demonstrated to exhibit several biological activities and health-promoting properties including antioxidative, anti-inflammatory, and anti-cancer activities. Therefore, these wastes are safe and beneficial compounds used in the production of functional foods, nutraceuticals, pharmaceuticals, and cosmetics. A conclusion can be reached by emphasizing the abundance of bioactive compounds in Citrus seed wastes, which makes them an excellent opportunity for increased environmental and economic utilization. [ABSTRACT FROM AUTHOR]

The management of the organic fraction of municipal solid waste (OFMSW), also called urban biowaste, and urban wastewater sludge (UWWS) represents a challenge for cities and regions, which want to adopt innovative urban bioeconomy approaches for their treatment and production of high-added-value products beyond the traditional anaerobic digestion (AD) and compost. This adoption is often restricted by the availability and maturity of technologies. The research object of this manuscript, based on the findings of EU Horizon 2020 project HOOP, is the identification of state-of-the-art circular technologies for material valorisation of OFMSW and UWWS, following a novel screening methodology based on the scale of implementation (tested at least at pilot scale). The screening resulted in 25 technologies, which have been compared and discussed under a multidisciplinary assessment approach, showing their enabling factors and challenges, their current or potential commercial status and their compatibility with the traditional technologies for urban biowaste treatment (composting and AD). The bioproducts cover market sectors such as agriculture, chemistry, nutrition, bioplastics, materials or cosmetics. Therefore, the results of this review help project promoters at city/region level to select innovative technologies for the conversion of OFMWS and UWWS into high value products. [ABSTRACT FROM AUTHOR]

Soil pollution by heavy metals (HMs) is a major environmental problem around the world. The addition of biowaste-based stabilizers for HM remediation has recently gained attention due to its relatively low cost and eco-risk, abundance, ease of operation, and quick remediation results. Among these stabilizers, shell (crustacean shell, bivalve shell, and eggshell), starfish, and bone-based stabilizers are particularly attractive because of their high Ca and P contents, allowing for highly efficient HM immobilization and simultaneous supplement of nutrients to the soil. However, a comprehensive review focusing on these stabilizers is currently missing. Therefore, this review attempts to summarize the HM immobilization efficiency of these stabilizers and the mechanisms associated with HM stabilization, and perform an operation cost estimation and cost comparison. Cost comparisons among different stabilizers are widely ignored in reviews due to the lack of reliable cost estimation tools or methods. However, for practical application in soil remediation, cost is one of the most important factors to consider. Thus, a simple but reasonable cost estimation method is developed and discussed in this review. Bivalve shell-based stabilizers demonstrated the most promising results for the immobilization of soil HMs in terms of higher performance and lower cost. Current research limitations, challenges, and recommendations regarding possible future research directions are also provided. [ABSTRACT FROM AUTHOR]

Bio-energy is the latest technology that is used to produce energy from organic materials known as biomass. It is a developing technology that produces energy without harming nature. Such a prominent source of brand-new energy is bio-battery because that has a highly promising future and is regarded as favorable to the environment. Also, so many researches are being done on bio-battery. They are a good, dependable source of energy and good for the environment. A bio-battery is an energy storage device powered by biomass. Glucose is the key element for the working of bio-batteries. Bio-batteries consist of an anode, cathode, separator, and electrolyte layered one on top of the other, much like any other battery. Bio-batteries use a sugar-digesting substance to digest glucose and produce electrons. In this proposed work, an attempt is made to utilize the waste and low-cost vegetables (which are sugar digestive) bought from the market as biomass for the production of bio-energy. The energy produced from the bio-battery for different sugar digestive substances was noted and compared with each other. Then the suitable and most efficient sugar digestive substance was tested at different conditions for higher energy production. [ABSTRACT FROM AUTHOR]

Exploring high-performance carbon anodes that are low-cost and easily accessible is the key to the commercialization of sodium-ion batteries. Producing carbon materials from bio by-products is an intriguing strategy for sodium-ion battery anode manufacture and for high-value utilization of biomass. Herein, a novel hard carbon (PPHC) was prepared via a facile pyrolysis process followed by acid treatment using biowaste pomegranate peel as the precursor. The morphology and structure of the PPHC were influenced by the carbonization temperature, as evidenced by physicochemical characterization. The PPHC pyrolyzed at 1100 °C showed expanded interlayer spacing and appropriate oxygen group content. When used as a sodium ion battery anode, the PPHC-1100 demonstrated a reversible capacity of up to 330 mAh g−1, maintaining 174 mAh g−1 at an increased current rate of 1 C. After 200 cycles at 0.5 C, the capacity delivered by PPHC-1100 was 175 mAh g−1. The electrochemical behavior of PPHC electrodes was investigated, revealing that the PPHC-1100 possessed increased capacitive-controlled energy storage and improved ion transport properties, which explained its excellent electrochemical performance. This work underscores the feasibility of high-performance sodium-ion battery anodes derived from biowaste and provides insights into the sodium storage process in biomass-derived hard carbon. [ABSTRACT FROM AUTHOR]

Biowaste management is one of the major concerns for the effective processing of the production of toxic and value-added products. Biowaste is generally either by-products or end products of numerous bioprocess industries, including agriculture, food, dairy, textile, paper, pulp, or biopharma industries. They may not only consist of numerous varieties of toxic substances but also contain the most useful energy sources, especially celluloses, which are abundant energy-rich derivatives from agricultural waste. This biowaste mismanaged, especially in agriculture bases countries like India and Asian countries by either burning or dumping, may cause severe environmental pollution. Microbial degradation of waste will be the best appreciable, cost-effective, and eco-friendly process, and the majority of biowaste can be easily degraded by several microbial communities, and biowaste can be effectively converted into less toxic or nontoxic. Among them, certain bacteria target plant-based celluloses which are acting as the main structural component of the majority parts of plant cells by producing cellulases. As this process results in diverse energy-rich derivatives such as cellobiohydrolase and glucose, further, these can be used for bioethanol production. To hydrolyse the polymeric structure of glucose that is abundant in most plant-based wastes, the enzyme cellulases are the most essential and categorised into four classes:exoglucanase, endoglucanase, cellobiohydrolases, and glucosidases. These will act at different sites of the cellulose for further degradation into glucose, a chief source for bioethanol production. There are numerous natural bacterial communities with higher potentials for the degradation of biowaste, especially cellulosic waste into energy-rich sugars highlighted besides other waste decomposition. It would be a futuristic approach to enhance the catalytic activity of microbial enzymes that convert cellulose into glucose for biofuel production. Similarly, there are other bacteria with protease activity on biowastes like soya, whey, and other food and dairy waste. This study emphasised on a natural isolate with multipotent efficiency in the degradation of numerous waste materials and optimisation for the degradation of numerous raw materials. This attempt will be contributing to the best biowaste utilisation and management of various production of biofuel. This study will emphasise the versatile activities of bacterial enzymes of a novel isolate, Bacillus which can lead to futuristic applications for the conversion of domestic waste into energy sources. [ABSTRACT FROM AUTHOR]

The recent over production of municipal solid waste (MSW) poses a significant threat to both the ecosystem and human health. Utilizing MSW for agricultural purposes has emerged as a promising strategy to reduce solid waste disposal while simultaneously increasing soil fertility. To explore this potential solution further, an experiment was designed to assess the impact of varying concentrations of MSW (25%, 50%, and 75%) on the proximate composition of 15 different vegetable species. The experiment, conducted between 2018 and 2019, involved treating soil with different levels of solid waste and analyzing the proximate components, such as crude protein, dry matter, crude fiber, crude fat, and moisture content, in the 15 selected crops. The results indicate that the application of 25% MSW significantly increased the levels of crude protein, crude fiber, dry matter, and fat in Spinacia oleracea, Solanum tuberosum, Solanum melongena, and Abelmoschus esculentus. Conversely, the addition of 75% MSW notably elevated the moisture and ash content in Cucumis sativus. Correlation and scatter matrix analyses were conducted to elucidate the relationships between the protein, fiber, dry matter, ash, and fat contents. Principal component analysis and clustering confirmed the substantial impact of Treatment_1 (25% MSW) and Treatment_3 (75% MSW) on the proximate composition of the aforementioned vegetables, leading to their categorization into distinct groups. Our study highlights the efficacy of using 25% MSW to enhance the proximate composition and nutritional value of vegetables. Nonetheless, further research is warranted to investigate the mineral, antioxidant, vitamin, and heavy metal contents in the soil over an extended period of MSW application. [ABSTRACT FROM AUTHOR]

Cellulose present in natural plant sources has better potentials to replace traditional synthetic fibers. However, a lack of knowledge and awareness on cellulose hinders efforts to fully utilize this extremely biodegradable resource. This study aims to extract and characterize the microcrystalline cellulose (MC) obtained from Pandanus tectorius leaves. The MC particles are extracted with the aid of alkaline and chemical treatment. The extracted MC powder is in pure white color and further investigated with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), ultraviolet–visible spectroscopy (UV), thermogravimetric analysis (TGA), and scanning electron microscopy analysis (SEM) to understand its physicochemical properties and surface morphology. The band gap energy of exfoliated MC was 4.21 eV; with crystallinity index and degree of crystallinity of 76.8% and 81.4%, the dislocation density is calculated as 0.002. Thermal stability of MC particle was up to 470 °C; further increment in temperature degrades the MC particles. The obtained results depict that exfoliated MC particles have better band gap, and it can be used for food packing industries, and furthermore, this type of waste plant weeds can be converted in to useful MC particles to be used as a filler material in developing polymer matrix composite. [ABSTRACT FROM AUTHOR]

In this study, high-strength zinc composites were fabricated using hydroxyapatite (HA) and wollastonite (WA) recovered from biowastes such as eggshells and rice husk ash for biomedical applications. The objective of this work is to evaluate the impact of hybrid reinforcement (HA and WA) particles on microstructural, mechanical, phase, and corrosion properties of novel Zn-1 Mg-0.2Ti/x(HA-WA) composite (x = 1, 5, and 10 wt.%) by squeeze casting method. XRD and FTIR characterization of the synthesized powders revealed the formation of pure HA phase and WA phase, milled for 10 h and calcined at 1000 °C for 1 h. Density measurement showed that Zn-1 Mg-0.2Ti/10(HA-WA) composite exhibited 25% density reduction compared to Zn-1 Mg-0.2Ti alloy. The hardness of Zn-1 Mg-0.2Ti/5(HA-WA) composite (82 HV) was over two times that of Zn-1 Mg-0.2Ti alloy (39 HV). Furthermore, Zn-1 Mg-0.2Ti/5(HA-WA) composite reported homogeneous distribution of the hybrid reinforcement along the grain boundary and the precipitate formation increased the mechanical properties of the composite. Zn-1 Mg-0.2Ti/5(HA-WA) composite reported the highest compressive strength as 364 MPa, which is comparable with the compressive strength of cortical bone (88–230 MPa). All the composites demonstrated dimples, cleavage planes, and lamellar cleavage facets, indicating a ductile and mixed-mode fracture. Electrochemical corrosion test revealed early passivation in Zn-1 Mg-0.2-Ti/5(HA-WA) composite with lower current density than higher reinforced composites. The proposed zinc composite, having improved microstructural, mechanical, and corrosion properties, may be helpful in various biomedical applications which involve load-bearing capacity and biodegradability, such as orthopedic implants. [ABSTRACT FROM AUTHOR]

In this study, CeO2-doped TiO2 nanoparticles were synthesized using an eco-friendly approach, utilizing an aqueous extract from the calyx leaves (outer covering) of Physalis peruviana fruits. The morphology of the greensynthesized nanoparticles was characterized using UV-Vis spectroscopy, FT-IR, SEM, and X-ray diffraction. The anti-inflammatory activity of the biosynthesized NPs was evaluated through a denaturation test. The use of the fruit's outer calyx, commonly discarded as food waste, presents a sustainable strategy for repurposing food and biological waste in nanotechnology. The NPs exhibited favorable magnetic properties, a well-defined crystalline structure, and notable anti-inflammatory effects, highlighting their potential for therapeutic and medical applications, particularly under green synthesis protocols. [ABSTRACT FROM AUTHOR]

Industrial and domestic human activities have a significant impact on the environment, contributing, among other things, to the increased pollution of natural waters. The spread of heavy metals is particularly dangerous to the health and life of living organisms due to the high accumulation potential of, among others, Cr (VI), Zn (II), Cu (II), Cd (II), Fe (II), and Ni (II). In order to remove, concentrate, and/or recover ions of these metals, various physical and/or chemical methods are commonly used. In this study, spent coffee grounds (SCGs) efficiently removed copper ions from simulated aqueous solutions, especially at low metal ion concentrations. Without additional modification, coffee grounds performed comparably to traditional adsorbents like activated carbon or ion exchangers. It was found that used ground coffee grounds effectively removed Cu (II) ions at a wide range of concentrations, with the highest efficiency (over 85%) obtained for dilute solutions. On the other hand, regeneration tests performed using a 10% hydrochloric acid solution successfully restored the coffee residue adsorbent, achieving a desorption efficiency of about 35%. This method concentrated the solution and facilitated efficient metal recovery by minimizing acid usage. The sorbent used is an innovative, cheap, and easy-to-use material with high sorption capabilities. [ABSTRACT FROM AUTHOR]

Abstract The recent over production of municipal solid waste (MSW) poses a significant threat to both the ecosystem and human health. Utilizing MSW for agricultural purposes has emerged as a promising strategy to reduce solid waste disposal while simultaneously increasing soil fertility. To explore this potential solution further, an experiment was designed to assess the impact of varying concentrations of MSW (25%, 50%, and 75%) on the proximate composition of 15 different vegetable species. The experiment, conducted between 2018 and 2019, involved treating soil with different levels of solid waste and analyzing the proximate components, such as crude protein, dry matter, crude fiber, crude fat, and moisture content, in the 15 selected crops. The results indicate that the application of 25% MSW significantly increased the levels of crude protein, crude fiber, dry matter, and fat in Spinacia oleracea, Solanum tuberosum, Solanum melongena, and Abelmoschus esculentus. Conversely, the addition of 75% MSW notably elevated the moisture and ash content in Cucumis sativus. Correlation and scatter matrix analyses were conducted to elucidate the relationships between the protein, fiber, dry matter, ash, and fat contents. Principal component analysis and clustering confirmed the substantial impact of Treatment_1 (25% MSW) and Treatment_3 (75% MSW) on the proximate composition of the aforementioned vegetables, leading to their categorization into distinct groups. Our study highlights the efficacy of using 25% MSW to enhance the proximate composition and nutritional value of vegetables. Nonetheless, further research is warranted to investigate the mineral, antioxidant, vitamin, and heavy metal contents in the soil over an extended period of MSW application.

The use of activated carbon (AC) to remove heavy metals and dyestuffs from heavy industry waste is widely preferred. In this study, a novel adsorbent AC obtained from peanut shell (PS)s by the green chemical activation (sodium thiosulphate and potassium chloride) method was used in the adsorbing process of Orange G (OG) from aqueous solutions. The surface area of the activated carbon was determined as 930.1 m2 g−1. Several parameters, such as pH, dye concentration, adsorbent amount, and temperature, were investigated in relation to the adsorption process. Isotherm, kinetic and thermodynamic analyses were performed using experimental adsorption data. Accordingly, the most appropriate isotherm model which described the system was the Langmuir isotherm (R2 = 0.999), and the most efficient kinetic model was pseudo-second order (R2 = 0.999). It was discovered that the adsorbent with a maximum adsorption capacity (qmax) of 294.12 mg g−1 is suitable for sustainable OG adsorption (RL = 0.044). The standard free energy (∆G°) values of the system were between −7.5 and −10.6 kJ mol−1 and negative ∆G° values increased in the negative direction, revealing that the adsorption process takes place by spontaneous physical adsorption. It was found that the adsorption process with positive enthalpy (∆H°) (14.5 kJ mol−1) was endothermic and with positive entropy (∆S°) (57.9 J mol−1 K−1) value increased the disorder at the solid-liquid interface. [ABSTRACT FROM AUTHOR]

Abstract Here, we describe the analysis of the capacitive performance of activated carbon materials derived from the biowaste of lemon. Lemon peel discarded by restaurants after juice extraction is carbonized at 400 0C followed by chemical activation using ZnCl2. The porosity of carbon materials is tailored by varying activation conditions, such as the mass ratio of carbonized lemon peel and ZnCl2, duration of heating, and temperature. The Brunauer–Emmett– Teller (BET) surface area and pore volume of carbon materials prepared at different activating conditions range from 1380 to 2120 m2g−1 and 0.38 to 0.69 cm3 g−1 respectively. The derived carbon materials are amorphous indicated by the broad peaks in the XRD pattern as well as disordered structure of the carbon materials is revealed by the Raman spectroscopic analysis. The systematic analysis of capacitive performance of activated carbons by employing electrochemical techniques like Cyclic Voltammetry (CV), Galvanostatic charge/Discharge (GCD) cycles, and electrochemical impedance spectroscopy (EIS) in acidic (H2SO4) and alkaline (KOH) media indicates that optimum condition for activation of lemon peel is 600 °C for 60 min with 1:1 mass ratio of carbonized lemon peel and ZnCl2. The superior performance of (ALP-600) is attributed to its high surface area and well-connected hierarchical porous structure. The tiny hump at ~ 0.2 V in CV might be due to the pseudocapacitive nature of oxygen functional groups indicated by FTIR. ALP-600 exhibits the highest specific capacitance of 180 Fg−1 and retains 99.7% of its initial capacitance after 5000 cycles in the acidic electrolyte. The maximum capacitance achieved with ALP-600 symmetric cell in CR2032 coin cell configuration is 0.90F.

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]

Artichokes (Cynara scolymus L.) are valuable foods, thanks to their health benefits, but they generate significant waste during their production, harvesting, and processing, which poses sustainability issues. This study applied an agroprospecting approach to convert Tema artichoke biowaste (TB) into valuable resources, starting from a global perspective of the production chain to the targeted applications based on chemical and biological analysis. The major TB was identified in the outer bracts of the immature flower heads, which were collected throughout the harvesting season, extracted, and analyzed. The most abundant compounds were phenolic acids including chlorogenic acid and caffeoylquinic derivatives. Among flavonoids, cynaroside was the most abundant compound. Multivariate analysis distinguished batches by collection period, explaining 77.7% of the variance, with most compounds increasing in concentration later in the harvest season. Subsequently, TB extracts were analyzed for their potential in wound healing and anti-aging properties. Fibroblasts were used to assess the effect of selected extracts on cell migration through a scratch wound assay and on cellular senescence induced by etoposide. The results show a significant decrease in senescence-associated β-galactosidase activity, γH2AX nuclear accumulation, and both p53 and p21 protein levels. Overall, this study ascribes relevant anti-skin aging effects to TB, thus increasing its industrial value in cosmeceutical and nutraceutical applications. [ABSTRACT FROM AUTHOR]

Leachable plasticizers made of petroleum are causing growing environmental and health concerns because they are so dangerous to the environment. Therefore, searching for novel biodegradable plasticizers is of increasing interest of researchers across different domains. So, there is a need to develop bio-based plasticizers from natural sources. Within this context, Agave sisalana act to be real alternatives to the chemical plasticizers because they are biocompatible and biodegradable. In light of these aspects, in this work, we explored a green plasticizer from Agave sisalana, a renewable resource. In this report, a compound was isolated from the residue after extracting from sisal leaf and its structure was investigated. Thermal investigations (TGA), X-ray diffraction, and Fourier transform infrared spectroscopy were used to assess its chemical stability and structure. The surface morphology of A. sisalana was examined in detail by scanning electron microscopy (SEM) and particle size is analyzed by using SEM/EDAX. The results show that the novel bioplasticizers have better qualities than the other traditional plasticizers. The crystallinity index and crystallinity size values of the A. sisalana leaf plasticizer were calculated through X-ray-diffraction for the isolated biomaterials. This exposed its amorphous-crystalline nature. The particle size of the extracted plant material was examined. The kinetic activation parameter was calculated by using TGA/DTG studies. The plasticizing effect of this novel bioplasticizers was also studied by reinforcing this with PLA matrix for biofilm manufacturing for futuristic applications. The conducted investigation showed that these bioplasticizers could be suitable for applications in the bioplastics sector. [ABSTRACT FROM AUTHOR]

Here, the hierarchical mesoporous-activated carbon particles obtained by KOH activation from pistachio shell wastes are modified by both the sulfonation process and CuO doping by hydrothermal heating (CuO@S-doped PSAC) for use as a supercapacitor. It is predicted that the electrochemical performance of the porous carbon electrode material obtained by such CuO doping and sulfonation process will be significantly increased with increased Faradaic capacitance. The electrochemical performance of CuO@S doped PSAC composite is systematically investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge/discharge (GCD) in the presence of 1 M H2SO4, 1 M Na2SO4, and 1 M NaOH as electrolytes. The CuO@S doped PSAC-based electrode shows excellent stability with high specific capacitance up to 397.16 F/g at 0.1 A/g and 92.64% retention. Furthermore, FTIR, SEM, XRD, EDS, and nitrogen adsorption/desorption analyses are used for the characterisation of the obtained composites. Based on a significant supercapacitor performance, the synthesis strategy of carbon-based electrode material containing sulfonation and CuO modifications derived from agricultural biomass waste material is predicted to be a valuable example. [ABSTRACT FROM AUTHOR]

The escalating accumulation of toxic wastes and biowastes constitutes a critical environmental crisis that demands immediate and effective solutions. Traditional waste treatment methods, predominantly chemical and physical, are increasingly viewed as unsustainable, burdened by high operational costs and the risk of generating secondary pollutants. Against this backdrop, bioremediation emerges as a crucial and sustainable alternative, utilizing the natural detoxifying capabilities of microorganisms. This review article focuses on the use of fungal and bacterial strategies in bioremediation, emphasizing their vital role in the degradation, stabilization, or detoxification of pollutants. We provide an in-depth analysis of the mechanisms by which fungi and bacteria break down various contaminants, presenting a current snapshot of the field's state of knowledge. The article highlights recent innovative advancements that improve the effectiveness and expand the applicability of bioremediation technologies. Moreover, it discusses the practical challenges of scaling these solutions to meet global environmental needs and suggests directions for future research and implementation. This synthesis not only underscores the significance of microbial bioremediation in addressing pressing environmental problems but also acts as a call to action for continued innovation in the sustainable management of hazardous wastes. [ABSTRACT FROM AUTHOR]

Anaerobic digestion (AD) is a promising biowaste valorization technology for sustainable energy, circular economy, local energy community growth, and supporting local authorities' environmental goals. This paper presents a systematic review meta-analysis methodology for biomethane estimation, using over 600 values of volatile solids (VS) content and biochemical methane potential (BMP) of six different waste streams, collected from 240 scientific studies. The waste streams include cow manure (CM), sheep/goat manure (SGM), wheat straw (WS), household waste (HW), organic fraction of municipal solid waste (OFMSW), and sewage sludge (SS). The statistical analysis showed a mean VS content of 11.9% (CM), 37.3% (SGM), 83.1% (WS), 20.8% (HW), 19.4% (OFMSW), and 10.6% (SS), with BMP values of 204.6, 184.1, 305.1, 361.7, 308.3, and 273.1 L CH4/kg VS, respectively. The case study of Kozani, Greece, demonstrated the methodology's applicability, revealing a potential annual CH4 production of 15,429,102 m3 (corresponding to 551 TJ of energy), with SGM, WS, and CM as key substrates. Kozani, aiming for climate neutrality by 2030, currently employs conventional waste management, like composting, while many local business residual streams remain unused. The proposed model facilitates the design and implementation of AD units for a sustainable, climate-neutral future. [ABSTRACT FROM AUTHOR]

The present paper explores the biological potential of bioactive compounds present in wine industry wastes, highlighting their valorization to promote sustainability and circular economy. Wine by-products, such as grape pomace and vine shoots, contain a high concentration of polyphenols, flavonoids, anthocyanins and other phytochemicals with antioxidant, anti-inflammatory and anticarcinogenic properties. Both conventional extraction methods, such as solid–liquid extraction, and emerging technologies, including enzyme-assisted extraction, ultrasound-assisted extraction, supercritical fluid extraction, microwave-assisted extraction, pressurized liquid extraction, high-hydrostatic-pressure extraction, and deep natural solvent-assisted extraction (NaDES), are discussed. In addition, the preservation of polyphenolic extracts by microencapsulation, a key technique to improve the stability and bioavailability of bioactive compounds, is addressed. The combination of advanced extraction methods and innovative preservation techniques offers a promising perspective for the valorization of bioactive compounds from wine residues, driving sustainability and innovation in the industry. [ABSTRACT FROM AUTHOR]

Organo-mineral fertilizers (OMFs) with low organic carbon (Corg) content have been associated with higher mineral fraction nutrient use efficiency. However, the extraction of peat, which is typically used in these OMFs, from endangered ecosystems causes long-time stored Corg to mineralize and to be released back into the atmosphere as carbon dioxide (CO2). This study analyzes the replacement of peat in OMFs with biowaste materials. These materials, considered organic byproducts that microorganisms and other living things can decompose through composting and aerobic or anaerobic digestion, offer a viable opportunity. This study investigated three stabilized biowastes--green compost (GC) from pruning residues, municipal solid waste compost (MSWC), and manure-based vermicompost (VC)--as the organic matrices for granular OMFs. These matrices were impregnated with dissolved ammonium sulfate and urea and used to coat diammonium phosphate granules. Each biowaste OMF contained 7.5% Corg, 20% mineral N, and 10% mineral P2O5 (OMF20-10). Fertilizers with high nutrient concentrations have the advantage of requiring low application volumes, facilitating their application in the field. Biowaste OMFs were compared with peat OMFs with the same Corg-N-P2O5 concentration. Peat and MSWC were also used to create OMFs containing 7.5% Corg, 10% mineral N, and 5%mineral P2O5 (OMF10-5). A 75-day tunnel trial was conducted under semi-controlled conditions using tomato plants (Solanum lycopersicum L.) fertilized to an equivalent of 81mg N kg-1 soil and 18mg P kg-1 soil. Controls included no fertilization (N0P0) and mineral N and P fertilization (MFNP). The Soil Plant Analysis Development (SPAD) chlorophyll meter and the BBCH (from German Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie) scale as well as the number of shoots weremeasured over time, as berry and total aboveground yield, N and P uptakes, and N and P use efficiencies (NUE and PUE, respectively) were calculated at harvest. All treatments outperformed the control N0P0 in most indicators. Peat20-10 did not have more berry yield than other OMF20-10; however, the higher number of shoots indicated a higher potential yield in the event of prolonging the experiment. At the end of 75 days, VC20-10 and MSWC20-10 showed similar PUE to peat, suggesting that those materials can be used as replacements. In the case of OMF10-5, MSWC10-5 had yield and N and P uptakes like peat OMFs, confirming the potential use of MSWC as peat replacement even at different nutrient concentrations. This research provides reassuring evidence of the effectiveness of biowaste OMFs, offering a positive outlook for sustainable agriculture. However, their use is not recommendable for short growing seasons. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) serves as a sustainable method to transform pine needle waste into nitrogen-doped (N-doped) hydrochars. The primary focus is on evaluating these hydrochars as catalytic electrodes for the oxygen reduction reaction (ORR) and carbon dioxide reduction reaction (CO2RR), which are pivotal processes with significant environmental implications. Hydrochars were synthesized by varying the parameters such as nitrogen loading, temperature, and residence time. These materials were then thoroughly characterized using diverse analytical techniques, including elemental analysis, density measurements, BET surface area analysis, and spectroscopies like Raman, FTIR, and XPS, along with optical and scanning electron microscopies. The subsequent electrochemical assessment involved preparing electrocatalytic inks by combining hydrochars with an anion exchange ionomer (AEI) to leverage their synergistic effects. To the best of our knowledge, there are no previous reports on catalytic electrodes that simultaneously incorporate both a hydrochar and AEI. Evaluation metrics such as current densities, onset and half-wave potentials, and Koutecky–Levich and Tafel plots provided insights into their electrocatalytic performances. Notably, hydrochars synthesized at 230 °C exhibited an onset potential of 0.92 V vs. RHE, marking the highest reported value for a hydrochar. They also facilitated the exchange of four electrons at 0.26 V vs. RHE in the ORR. Additionally, the CO2RR yielded valuable C2 products like acetaldehyde and acetate. These findings highlight the remarkable electrocatalytic activity of the optimized hydrochars, which could be attributed, at least in part, to their optimal porosity. [ABSTRACT FROM AUTHOR]

In vitro studies were undertaken aiming to study the methane (CH4) mitigation potential of biowaste (BW) of Padina gymnospora at the graded inclusion of 0% (C), 2% (A2), 5% (A5), and 10% (A10) of the diet composed of straw and concentrate in 40:60 ratio. The chemical composition analysis revealed that the BW contained higher crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and ether extract (EE) than the PF (fresh seaweed, P. gymnospora). The concentration of cinnamic acid, sinapic acid, kaempferol, fisetin p-coumaric acid, ellagic acid, and luteolin in BW was 1.5-6-folds less than the PF. Inclusion of BW decreased (P < 0.0001) CH4 production by 34%, 38%, and 45% in A2, A5, and A10 treatments, respectively. A decrease (P < 0.0001) of 7.5%-8% in dry matter (DM) and organic matter (OM) digestibility was also recorded with the BW supplementation. The BW inclusion also decreased the numbers of total (P = 0.007), Entodinomorphs (P = 0.011), and Holotrichs (P = 0.004) protozoa. Metagenome data revealed the dominance of Bacteroidetes, Proteobacteria, Firmicutes, Actinobacteria, and Fibrobacter microbial phyla. At the phylum level, Euryarchaeota dominated the archaeal community, whereas Methanobrevibacter was most abundant at the genus level. It can be concluded that the inclusion of BWin straw and concentrate based diet by affecting rumen fermentation, protozoal numbers, and compositional shift in the archaeal community significantly decreased CH4 production. Utilization of biowaste of P. gymnospora as a CH4 mitigating agent will ensure its efficient utilization rather than dumping, which shall cause environmental pollution and health hazards. [ABSTRACT FROM AUTHOR]

Fruit juice industry generates huge amounts of waste by-products such as peel, leaf, and pulp, which might be alternative natural antioxidant source for the development of novel functional foods. In this study, plum was selected as the source of waste by-products. Peel comparing to leaf and pulp has been determined as the richest source (7–9 times more) in terms of the major phenolic compound (cyanidin-3-glucoside). Automatic solvent extraction (ASE) has been used to extract high added-value substances from the peels. In order to optimize the ASE system, response surface method (RSM) was used as statistical experimental design approach. Box-Behnken design type of RSM produced 17 experimental runs. The best phenolic (TPC), flavonoid (TFC) and cyanidin-3-glucoside yields of plum peel extract were found to be 34.94 mg-GAE, 612.96 mg-CE and 21.19 mg per g fresh peel under the optimal conditions (37% ethanol concentration, ∼20% acid concentration, and 35 min of time). Additionally, antioxidant activity test results performed by 2 methods (DPPH and ABTS) show that the selected raw material is a source of potential antioxidant additive in food formulations. [ABSTRACT FROM AUTHOR]

It is a truism by now that the combustion of fossil fuels has execaerbated climate change, and its repercussions. Biomass in pelletised form, will emerge as substitutes, in the circular bioeconomies of the future. This brief review focuses on the utilisation of agricultural residues as raw materials for pellets, and explores the aspects of sustainability - socio-cultural, economic, environmental, and techno-functional - in the 20-plus peer-reviewed articles selected for that purpose using Scopus with a set of search-phrases. The articles are case studies dated between 2012 to 2023, tracing their provenance to different countries in the world - Brazil, Canada, China, Denmark, Greece, India, Italy, Mexico, Peru, Spain, Thailand, Türkiye, Zambia, etc. Among the many gleanings which are reported in this review, some deserve mention here in the abstract. The social aspect of sustainability has not been studied as much as the economic and environmental. The case studies emphasize the importance of adapting the pelleting process to the properties of the agricultural/horticultural residues and the prevalent local conditions. It is encouraging to note that there is a surfeit of agricultural residues (corn, coffee, quinoa, beans, oats, wheat, olives, tomatoes, pomegranates, grapes, etc. in the articles reviewed) which can be valorised to pellets, also in combination with the in-vogue forestry wastes. This is more advisable if the status quo is open burning of such residues in the fields. The journey towards the sustainable development goals (SDGs) will be aided by investments in such biorefinery-projects, SDG 17 is extremely vital for their success - collaboration and cooperation among several stakeholders around the world. This review, though based on only 20-plus articles from around the world, is an in-depth analysis which promises to be of interest to decision-makers and sustainability-specialists keen on contributing to the transition to a circular bioeconomy. [ABSTRACT FROM AUTHOR]

Silica (SiO2) plays a major key ingredient in producing products such as toothpaste, ceramics, and paints, to name a few, as it acts as a stabilizing agent, filler and additive. Due to its excellent properties, the use of high-purity SiO2 in industrial applications is favourable. Unfortunately, high-purity SiO2 is expensive. Tetraethyl Orthosilicate (TEOS) is an example of a SiO2 precursor that is costly and harmful, yet frequently employed. This paper provides a short review of the advantages of biowaste materials as SiO2 precursors and their role as fillers in the fabrication of superhydrophobic coating. Researchers nowadays are attempting to lower the expense of employing high-purity SiO2 by extracting silica from biowaste using many methods such as acid leaching and alkali treatment as this option is highly sustainable. The growth of agricultural industries is exponential due to the increase in biowaste production. Therefore, this is one of the ways to utilize the use of biowaste in combatting the environmental issues regarding excess biowaste and receding pure resources. SiO2 from biowaste also can be utilized as filler and used to develop superhydrophobic coating, providing numerous potential applications. [ABSTRACT FROM AUTHOR]

Due to developing technology and increasing population, human needs have increased, and textile activities have gained momentum. Many synthetic dyestuffs are used to meet the needs in this field. In this study, a cheap, useful, innovative, environmentally friendly and sustainable adsorbent was developed for the removal of Methylene Blue(MB), which is one of the dyes that is harmful to the environment. In the cultivation of fruit trees, in addition to the product, very high amounts of by-products/waste (garbage, branches, bark, leaves, etc.) are produced. In this direction, fig tree wastes were immobilized with chitosan, made magnetic, and MB adsorption on the developed adsorbent was examined in a batch system. Glutaraldehyde was used as crosslinker. Characterization of synthesized glutaraldehyde cross-linked chitosan-coated magnetic vegetable waste composite beads (g-CMBW) was carried out by SEM, EDX, FTIR and XRD. In the study, the effects of temperature (25–55 °C), pH (3.0–8.0), initial MB concentration (10–250mg/L), contact time (5–360min) and the amount of adsorbent (2–10 g/L) on MB adsorption with g-CMBW were examined. The optimum conditions obtained were determined as pH 6.0, temperature 25 °C, adsorbent amount 6 g/L, and contact time 120 min. The maximum adsorption capacity in MB removal using g-CMBW composite beads was calculated as 103.1 mg/g according to the Langmuir isotherm model. The temperature studies showed that the adsorption capacity decreased with increasing temperature, showing that the system was exothermic. In light of these results, it was determined that there are new promising adsorbents of natural origin, with higher adsorption capacity, lower cost, and alternatives to commercially used adsorbents in the removal of MB from aqueous media. In this study, we developed a renewable magnetic composite bead as a low-cost pioneer based on a new sustainable biopolymer using chitosan and plant waste. The novelty of this work is based on the development of a new composite adsorbent that can be synthesized in a fast, simple, and environmentally friendly method, not requiring expensive reagents or complex equipment. Another innovation is that methylene blue, a common micropollutant, can be easily removed from polluted water using simple biowaste-based adsorbents by adopting appropriate procedures. It exhibited higher micropollutant adsorption performance compared to most other adsorbents. These results showed that it could be a very effective adsorbent for methylene blue removal from aqueous media. [ABSTRACT FROM AUTHOR]

Harmful cyanobacteria blooms and the escalating impact of cyanotoxins necessitates the effective removal of cyanobacteria from water ecosystems before they release cyanotoxins. In this study, cyanobacteria removal from water samples taken from the eutrophic Aleksandrovac Lake (southern Serbia) was investigated. For that purpose, novel activated carbons derived from waste biomass—date palm leaf stalk (P_AC), black alder cone-like flowers (A_AC), and commercial activated carbon from coconut shell (C_AC) as a reference were used. To define the best adsorption conditions and explain the adsorption mechanism, the influence of contact time, reaction volume, and adsorbent mass, as well as FTIR analysis of the adsorbents before and after cyanobacteria removal, were studied. The removal efficiency of P_AC and A_AC achieved for the applied concentration of 10 mg/mL after 15 min was ~99%, while for C_AC after 24 h was only ~92% for the same concentration. To check the safety of the applied materials for human health and the environment, the concentrations of potentially toxic elements (PTEs), the health impact (HI) after water purification, and the toxicity (MTT and Comet assay) of the materials were evaluated. Although the P_AC and A_AC achieved much better removal properties in comparison with the C_AC, considering the demonstrated genotoxicity and cytotoxicity of the P_AC and the higher HI value for the C_AC, only the A_AC was further investigated. Results of the kinetics, FTIR analysis, and examination of the A_AC mass influence on removal efficiency indicated dominance of the physisorption mechanism. Initially, the findings highlighted the superior performance of A_AC, with great potential to be globally commercialized as an effective cyanobacteria cell adsorbent. [ABSTRACT FROM AUTHOR]

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The saw-milling residues are biowaste generated during the sawing of logs into lumber, and they may be lucrative when turned into biowaste pellets. Using biowaste as a renewable fuel helps address the limited availability of fossil fuels, reduces pollution, and additionally decreases the need for landfill. This study investigated the thermal reaction kinetics and physical properties of oxidative torrefied sawdust (TSD) and waste medical plastic pyrolysis oil (WMPPO) blended pellets, TSD25 and TSD50, referring to 25% and 50% of WMPPO with TSD, respectively, using thermogravimetric analysis (TGA), whereas the pellets are prepared using a small-scale pellet processing system. The reported additional physicochemical properties like density, pellet durability index (PDI), moisture adsorption, and impact resistance (IR) were as per the American Society of Agricultural and Biological Engineers (ASABE) recommended tests for densified fuel pellets, proximate Fourier transform infrared spectroscopy (FTIR) were used for identifying the blend's chemical composition active constituents. Ultimate analysis was carried out for the elemental analysis, and the morphological study was conducted using scanning electron microscopy. The samples have a moisture content of less than 10%, a volatile matter content that seems to be 75 to 82%, and an ash content that seems to be 1.05 to 6.65%. Oxidative torrefied sawdust scanning electron micrographs reveal micro, macro, and meso pores and improved the Brunauer-Emmett-Teller (BET) surface area. FTIR and TGA validate the addition of 50% WMPPO with TSD-controlled combustion zone temperature with the activation energy of 27.63 kJ/mol for an effective thermal conversion process. The physicochemical properties of density, pellet durability index (PDI), moisture adsorption, and impact resistance (IR) for sawdust (SD), TSD, and TSD blends with WMPPO are also reported. Both low-temperature torrefaction and waste medical plastic pyrolysis oil blending reduce volatile loss and improve fuel pellet physicochemical and thermochemical characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • The biological CO production in the compost pile was carried out by bacteria. • Bacteria isolated from compost produced CO with concentration > 1000 ppm. • The most common genus in compost was Bacillus with four representatives. • B. paralicheniformis and B. licheniformis produced the highest concentrations of CO. • High CO concentrations were accompanied by low O 2 (<6%) and high CO 2 levels (>8%) Carbon monoxide (CO) formation has been observed during composting of various fractions of organic waste. It was reported that this production can be biotic, associated with the activity of microorganisms. However, there are no sources considering the microbial communities producing CO production in compost. This preliminary research aimed to isolate and identify microorganisms potentially responsible for the CO production in compost collected from two areas of the biowaste pile: with low (118 ppm) and high CO concentration (785 ppm). Study proved that all isolates were bacterial strains with the majority of rod-shaped Gram-positive bacteria. Both places can be inhabited by the same bacterial strains, e.g. Bacillus licheniformis and Paenibacillus lactis. The most common were Bacillus (B. licheniformis, B. haynesii, B. paralicheniformis, and B. thermolactis). After incubation of isolates in sealed bioreactors for 4 days, the highest CO levels in the headspace were recorded for B. paralicheniformis (>1000 ppm), B. licheniformis (>800 ppm), and G. thermodenitrificans (∼600 ppm). High CO concentrations were accompanied by low O 2 (<6%) and high CO 2 levels (>8%). It is recommended to analyze the expression of the gene encoding CODH to confirm or exclude the ability of the identified strains to convert CO 2 to CO. [ABSTRACT FROM AUTHOR]

The Adrar region (Algeria) has a total of 397,800 date palm trees (Phoenix dactylifera L.). Due to annual palm cleaning, large quantities of lignocellulosic biomass are produced. Depending on the variety, an average of 65 kg of biowaste is obtained per palm tree. Since the value of this biowaste is underrated, most of the palms are burned outdoors, causing air and visual pollution. This work explores the gasification potential of lignocellulosic waste from date palms (Phoenix dactylifera L. Takarbouche variety) into useful energy. The technology investigated is air updraft fixed-bed gasification, thanks to an originally designed and built reactor, with the capability to process 1 kg of feedstock. Four types of palm waste—namely, palms, petioles, bunch, and bunch peduncles—are first characterized (bulk density, proximate analysis, fixed carbon, elemental composition, and calorific value) and then used as feedstock for two gasification tests each. The syngas produced for the four date palm wastes is combustible, with an outlet temperature between 200 and 400 °C. The operating temperature inside the gasifier varies according to the feature of the biomass cuts (from 174 °C for the peduncles to 557 °C for palms). The experimental setup is also equipped with a cyclone, allowing for the recovery of some of the tar produced during the tests. Finally, the results show that the residence time has a positive effect on the conversion rate of date palm waste, which can significantly increase it to values of around 95%. [ABSTRACT FROM AUTHOR]

Purpose: Agroforestry biowaste compiles large amount of solid waste, which could be pyrolyzed into biochar and applied as soil amendment. The application of biochar has emerged as an excellent tool to mitigated the greenhouse gases emissions. However, effects of biochar could be varied according to soil type, feedstock type and rate of biochar application. Materials and methods: We studied the effect of three types of biochar (FS, fruit shell of Camellia oleifera-based; MS, spent mushroom substrate-based and RS, rice straw-based) on N2O emissions with nitrogen treatment N (urea, 0 and 0.02%) from and two soils with different origin (rice paddy soil, RPS and C. oleifera plantation soil, CPS). Results and discussion: FS and MS biochar significantly reduced N2O emissions in fertilized CPS by 66% and 33%, respectively, while that in RPS were increased by 74% and 49%, respectively. After RS biochar addition, N2O emissions were decreased by 82% only in fertilized CPS, indicating that FS and MS biochar applied in soil with the same origin as those of biochar feedstocks efficiently mitigated N2O emission rates. The relatively lower soil pH in CPS increased profoundly relative to RPS after biochar was added which contributed substantially to N2O emissions reduction, that result could be supported by the increased abundance of nosZ in RPS with nitrogen and biochar. Simultaneously, the higher soluble C and N of MS and FS biochar could increase that of RPS after application, which could further enhance N2O emissions in RPS. Conclusions: Biochar mitigated more N2O in soils with the same origin as that of biochar feedstocks compared with that of different origin ecosystems. Mitigating N2O emissions should consider the origin ecosystem of both biochar feedstock and soils, both of which profoundly impact the outcome of soil N2O mitigations. [ABSTRACT FROM AUTHOR]

The growing production of biowaste is causing serious environmental concerns, and composting has emerged as an environmentally friendly solution. This approach contributes to the real circular economy of biowaste, avoiding landfill disposal. This process is flexible as it can be carried out on a domestic or industrial scale. This work focused on the formulation and monitoring of two different composting processes (on a laboratory and domestic scale), to recover biowaste from a university canteen and a rural household, as well as evaluating the quality of the final composts. Three different mixtures of canteen food waste (CFW) and olive wood chips (OWC) were tested at lab scale (CFW:OWC 100:0, 40:60, and 60:40%), with two replicates carried out on the second mixture; a single mixture was tested at the domestic experiment (40:60%). The results showed that both processes reached thermophilic temperatures, with a peak of 65 °C on the lab scale and 75 °C recorded in the domestic composting. Reaching thermophilic temperatures is essential in composting, to maximize the rate of organic matter (OM) decomposition and improve compost quality (e.g., stability and maturation). The moisture content (MC) of biowaste proved to be a critical parameter since the high MC of CFW led to the inhibition of the aerobic process in the mixture without OWC (100% of CFW). On the contrary, a large quantity of OWC (60:40%) showed lower biodegradability due to the presence of lignocellulosic compounds. Analysis of the quality of the final compost revealed that although domestic composting was a process with a low level of control, it allowed obtaining quality compost for agronomic applications, similar to that produced on a laboratory scale. All final composts (after 120 days) were stable and mature, according to the oxygen uptake rate (OUR) and the germination index (GI). Indeed, OUR complied with the regulatory limits (15 and 25 mmolO2/kgOM.h) to be considered soil correctives or organic fertilizers, evidencing the stability of the materials. All composts are non-phytotoxic (GI above 80%), meaning that they are suitable for plant growth. The composts produced retained a significant amount of carbon (40–70%), with a high value for returning carbon to the soil in stable OM forms. Thus, when applied to the soil, a significant amount of carbon is carried to this compartment, making a valuable contribution to closing the carbon cycle and avoiding the emission of CO2 into the atmosphere. Overall, it was possible to conclude that biowaste from university canteens and households can be recovered by composting, as long as it is mixed with a bulking agent (such as OWC), which promotes the process and improves the properties of the composts. [ABSTRACT FROM AUTHOR]