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Oat milk production is increasing due to consumer demand for nutritious dairy alternatives. Oat pulp is an insoluble residue and the main by-product of oat milk production. Approximately 0.2–0.45 kg of oat pulp is generated from every 1 kg of oat milk, and an estimated 228 kilotons is produced annually on a global scale, which is projected to increase to 500 kilotons by 2030. Oat pulp is rich in protein, dietary fibre, β-glucan, lipids, and bioactive compounds, but rapidly degrades due to microbial activity, and this byproduct is currently discarded to landfills with an associated negative impact on the environment. To promote the valorisation of oat pulp, it is important to understand the nutritional profile, oat milk processing, and its current applications. This review outlines and discusses oat milk production, nutrition, functionality, and food applications of oat pulp, and then proposes research trends for the valorisation of oat pulp, including fractionation into protein, dietary fibre, starch, and bioactive-rich fractions with potential use for various purposes. Cost-effective utilization of oat pulp and similar by-products is vital in tackling both environmental issues and the escalating need for sustainable food production. [ABSTRACT FROM AUTHOR]

This study aimed to enhance the economic viability and sustainability of the cotton industry by converting cottonseed into energy. Cottonseed was subjected to lipid extraction for biodiesel production, and a pyrolysis test was conducted under N2 and CO2 conditions to valorise defatted cottonseed. Under CO2 conditions, the increase in CO concentration was due to homogeneous reaction of CO2 with volatile matters. Biochar, a pyrolytic product of defatted cottonseed, was used as a catalyst for thermally induced transesterification, and showed high performance in biodiesel conversion efficiency due to its abundant alkaline earth metals and meso-/macro-pores. For example, transesterification using silica at 250 ˚C yielded only 1.6 wt.% biodiesel, whereas using biochar at the same temperature resulted in a significantly higher biodiesel yield of 83.5 wt.%. This study experimentally proved that 7,900 tons (304 million MJ) of biodiesel could be produced annually, surpassing the diesel fuel requirement (145 million MJ) for cotton cultivation. These results indicate the potential to fully replace fossil fuels in the cotton industry. Article highlights: Oil was extracted from cottonseed, and the defatted cottonseed was used in pyrolysis to produce syngas and biochar. Biochar demonstrated catalytic properties in thermally induced transesterification of cottonseed extracts into biodiesel. Biochar outperformed conventional silica, providing a biodiesel yield of 83.5 wt.% at 250 ˚C (silica: 1.6 wt.%). [ABSTRACT FROM AUTHOR]

Wet storage effects on fly ash mean that processing may be necessary to achieve the physical properties required for use in concrete. This paper considers drying, de-agglomeration and milling of various wet stored fly ashes at laboratory and pilot/benchtop scales, towards meeting these. In the laboratory, different batch quantities and milling times with as-received/pre-screened materials were examined using a ball mill. Greater particle size reductions were obtained with increased milling time but at gradually reducing rates. Pre-screening and batch quantity had relatively minor effects on particle size reductions, with small differences also found between wet and dry stored fly ash. Extended milling time resulted in a darkening of colour; slight increases in loss-on-ignition, the main oxides content and crystalline components; reductions in water requirement (to a point); and greater reactivity. Similar effects were generally noted in concrete for the superplasticising admixture dose to achieve a target slump and compressive (cube) strength. At pilot/benchtop scale, a dryer-pulveriser and spiral jet mill were used, which gave general agreement with the behaviour noted in the laboratory, but with the effects tending to be less. Fineness levels in Standards were achievable, with subsequent performance in concrete, appearing to depend on the milling process used. [ABSTRACT FROM AUTHOR]

The aim of this work is to provide a new composite material for applications in the thermal insulation of buildings. The composite was made with mortar reinforced with natural fibres extracted from the petiole of the Washington robusta (WR) palm tree. The fibres used were first chemically characterised by energy-dispersive X-ray spectroscopy, scanning electron microscopy, X-ray and infrared diffractometry spectroscopies alongside tensile testing to discover their morphological structure. Afterwards, the fibres were incorporated into mortar with mass percentages varying from 0 to 4% to determine experimentally the thermomechanical properties of the manufactured samples. The chemical findings indicated that WR fibres are rich in cellulose, hemicellulose and lignin, and possess a high crystallinity index, which enhances the mechanical properties and durability of the composite. The density obtained for the composite W2RC4% is 1305 kg/m3 and less than 2000 kg/m3; this composite can thus be classified as a lightweight concrete according to the standard NF EN 206 + A2/CN (2022). The thermal conductivity and thermal effusivity dropped by about 60% and 42%, respectively. Moreover, the WR reduces the compressive strength (76%) and the flexural strength (36%) to minimum values, respectively, of 5.9 MPa and 3.8 MPa. These values meet the mechanical requirements of lightweight concretes (> 3.5 MPa). [ABSTRACT FROM AUTHOR]

This study evaluated the recovery of amorphous calcium phosphate and vivianite from industrial wastewater produced by a toothpaste manufacturing facility, where phosphorus concentrations exceed 3,000 mg L−1. The goal was to reduce the phosphorus concentration on-site to below 20 mg P L−1, so that treated wastewater can be discharged to a municipal wastewater treatment plant. In bench-scale experiments, various dosages of Ca(OH)2 (10–25 g L−1) and FeSO4·7H2O (20–60 g L−1) were evaluated to identify optimal conditions for precipitating >99% of the phosphorus. Pilot-scale experiments showed that recovery of amorphous calcium phosphate required dosing 25 g L−1 Ca(OH)2 and mixing for 60 min, whereas recovery of metavivianite required co-dosing 60 g L−1 FeSO₄·6–7H₂O and 7.2 g L−1 NaOH and mixing for 15 min. Variations in influent wastewater composition were found to significantly affect the pH as well as concentrations of residual Fe2+ and Ca2+ in the treated wastewater. Impurities present in chemicals used for precipitating phosphorus were found to influence purity of the recovered phosphate products. The chemical demand for recovering 99% of the phosphorus in the toothpaste industry wastewater was found to be significantly higher than for recovering 95% of the phosphorus in conventional municipal wastewater. This was due to a higher treatment goal and the unique composition of the wastewater, characterised by its high ionic strength and elevated concentrations of Na+ and Cl−, which potentially inhibited nucleation and crystal growth during chemical precipitation. A preliminary economic analysis indicated that recovering vivianite, with potential applications in the electronics industry, could generate significantly higher profits compared to amorphous calcium phosphate, but this depends on the product purity. Overall, this study highlights the potential for industrial wastewater to contribute to a circular phosphorus economy. [ABSTRACT FROM AUTHOR]

Regulatory and market forces compel companies to integrate transparency and sustainability into their operations. In response to the pressing need, the study proposes a blockchain-enabled, sustainable, integrated three-layer inventory model for the cheese industry under carbon cap-and-trade policy. The ultimate aim is to maximize the integrated total profit of the system with optimal investment in green technology. Prior studies have neglected to account for blockchain costs and spoilage rate control, whereas our findings demonstrate that strategic investments in preservation technology yield substantial reductions in spoilage rates. Results indicate that the downstream end of the supply chain, retail, also plays a crucial role in maintaining total profitability, indicating the significance of collective inventory management along with sustainability initiatives. This study concludes that technology-driven sustainability initiatives, coupled with effective spoilage management, can optimize sustainability outcomes in the cheese supply chain without compromising financial performance. [ABSTRACT FROM AUTHOR]

Fruit and vegetable industrialisation is a major contributor to food waste; thus, its integral transformation into functional powders has gained attention. Pretreatments can be incorporated into valorisation processes to generate structural or biochemical changes that improve powders' characteristics. This study deepens into the impact of biological (fermentation, FERM) and thermophysical (autoclaving, AUTO; microwaves, MW; ultrasound, US; and pasteurisation, PAST) pretreatments, combined with dehydration (hot air-drying, HAD; or freeze-drying, FD) on the characteristics of powdered products obtained from broccoli stems. The impact of pretreatments on physicochemical (moisture, water activity, total soluble solids) and antioxidant properties (phenols, flavonoids, antioxidant capacity by ABTS and DPPH) on residue and powdered products was studied, together with their impact on plant tissue structure (Cryo-SEM) and the powders' phenolic profile (HPLC). Probiotic viability was also determined on the fermented samples. The pretreatments applied, particularly the ultrasound, improved the antioxidant properties of the broccoli stems compared to the unpretreated samples, in line with microscopic observations. Dehydration did also improve the antioxidant attributes of the broccoli wastes, especially drying at 60 °C. However, pretreatments combined with dehydration did not generally lead to an improvement in the antioxidant properties of the powders. Probiotic properties were preserved in the freeze-dried products (>107 CFU/g). In conclusion, pretreatments may be applied to enhance the antioxidant attributes of broccoli wastes, but not necessarily that of dried powdered products. [ABSTRACT FROM AUTHOR]

Synthetic textiles such as polyesters are essential for daily life. However, large‐scale production generates large amounts of waste. This study introduces a new approach for valorising polyester textile waste (PTW) by transforming it into a catalyst for biodiesel production via pyrolysis. Specifically, a metal/carbon composite (PTW + steel slag [SS] composite—PSC) with enhanced catalytic properties was prepared by pyrolysing PTW with SS. The alkaline metals in SS facilitate the carbonisation of PTW via decarboxylation, resulting in a PSC rich in carbon, iron, and alkaline compounds. This composite featured mesopores that were larger than the micropores (MPs) typically found in PTW char. The use of porous material (silica) in thermally induced transesterification has been proven to be an efficient method for biodiesel production, achieving a yield of 97.20 wt.% in 1 min (faster than the 93.82 wt.% yields in 60 min observed from conventional alkali‐catalysed transesterification). However, the high reaction temperature (≥ 360°C) poses economic/technical challenges. To overcome this, PSC has been employed as a catalyst in thermally induced transesterification, leveraging its mesoporous structure and high alkaline content, particularly calcium oxide. The PSC achieved a biodiesel yield of 98.10 wt.% at a markedly lower reaction temperature of 120°C within 1 min. This performance was not attainable using silica or PTW char under similar conversion conditions. These findings highlight the potential of PSC produced through the pyrolysis of PTW and SS as effective catalysts for biodiesel production. This process is a promising strategy for converting waste into valuable resources and mitigating the environmental impacts associated with polyester waste. [ABSTRACT FROM AUTHOR]

Summary: This study investigated the physicochemical, microscopical, and functional properties of chickpea (Cicer arietinum) okara flours. The flours were prepared from chickpea okara obtained as a by‐product following the preparation of chickpea beverages using conventional, microwave, and ultrasound processing. The assessment of the okara flours focused on evaluating the influence of the processing methods on their physicochemical, functional, and microstructural characteristics. Through comprehensive analyses, the study examined how the different processing techniques affected the composition and properties of the resulting okara flours. Furthermore, the study included a comparative mass balance analysis to assess the extraction efficiency of the three processing methods. The findings revealed significant variations in the composition and properties of the okara flours among the different processing methods. Each method exhibited unique effects on the physicochemical, functional, and microstructural attributes of the resulting flours. Consequently, it was not possible to identify a single "best" processing method for obtaining optimal okara flour characteristics since all flours had interesting and unique properties. Overall, this study provides valuable insights into the effects of different processing methods on chickpea okara flour. The findings highlight the importance of selecting an appropriate processing technique based on the desired properties and applications of the flour. The results can contribute to the development of tailored processing approaches for enhancing the utilisation of chickpea okara flour in various food formulations, thereby promoting sustainability and reducing waste in the food industry. [ABSTRACT FROM AUTHOR]

The remediation of dredged sediments (DS) as a major waste generation field has become an urgent environmental issue. In response to the limited strategies to restore DS, the current study aimed to investigate the suitability of Paulownia tomentosa (Thunb.) Steud as a tool for decontamination of DS, both independently and in combination with a sewage sludge-based biochar. The experimental design included unamended and biochar-supplemented DS with the application rates of 2.5, 5.0, and 10.0%, in which vegetation of P. tomentosa was monitored. The results confirmed that the incorporation of biochar enriched DS with the essential plant nutrients (P, Ca, and S), stimulated biomass yield and improved the plant's photosynthetic performance by up to 3.36 and 80.0 times, respectively; the observed effects were correlated with the application rates. In addition, biochar enhanced the phytostabilisation of organic contaminants and shifted the primary accumulation of potentially toxic elements from the aboveground biomass to the roots. In spite of the inspiring results, further research has to concentrate on the investigation of the mechanisms of improvement the plant's development depending on biochar's properties and application rate and studying the biochar's mitigation effects in the explored DS research system. [ABSTRACT FROM AUTHOR]

The global demand for sustainable and non-toxic alternatives across various industries is driving the exploration of naturally derived solutions. Hydrosols, also known as hydrolates, represent a promising yet underutilised byproduct of the extraction process of essential oils (EOs). These aqueous solutions contain a complex mixture of EO traces and water-soluble compounds and exhibit significant biological activity. To fully use these new solutions, it is necessary to understand how factors, such as distillation time and plant-to-water ratio, affect their chemical composition and biological activity. Such insights are crucial for the standardisation and quality control of hydrosols. Hydrosols have demonstrated noteworthy properties as natural antimicrobials, capable of preventing biofilm formation, and as antioxidants, mitigating oxidative stress. These characteristics position hydrosols as versatile ingredients for various applications, including biopesticides, preservatives, food additives, anti-browning agents, pharmaceutical antibiotics, cosmetic bioactives, and even anti-tumour agents in medical treatments. Understanding the underlying mechanisms of these activities is also essential for advancing their use. In this context, this review compiles and analyses the current literature on hydrosols' chemical and biological properties, highlighting their potential applications and envisioning future research directions. These developments are consistent with a circular bio-based economy, where an industrial byproduct derived from biological sources is repurposed for new applications. [ABSTRACT FROM AUTHOR]

The aim of this study is to assess the feasibility of using foundry by-products in porcelain tiles. This feasibility has been evaluated by three different perspectives: technical, radiological and environmental. Firstly, given that the main impurities in foundry by-products are carbon and organic compounds, thermal treatments that successfully reduce carbon and organic compounds have been evaluated. Subsequently, both calcined and uncalcined by-products have been characterised from a technological and radiological point of view and finally, porcelain tile compositions with both calcined and uncalcined by-products have been obtained. These compositions were fully characterised and their performance in the manufacturing process has been evaluated. The environmental impacts of this recycling process were also assessed by means of a life cycle assessment. The results confirm that foundry by-products can partially replace sand in porcelain tile bodies. [ABSTRACT FROM AUTHOR]

Fluorine-containing silicon residue (FSR) is a solid waste that is harmful to the environment. A new alkali-free liquid accelerator based on aluminium sulfate (LAFS) was prepared using FSR. The addition of LAFS to cement mortar shortened the setting times and significantly improved the early strength. With the addition of 8% LAFS, the initial and final setting times were 2.48 min and 11.83 min, respectively, and the 1-day compressive strength was 14.6 MPa, which was 200% of that of the mortar without LAFS. The mechanism of the action of LAFS was studied using isothermal calorimetry test, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and other analytical methods. The results showed that the LAFS rapidly generated a large amount of ettringite and promoted the formation of calcium silicate hydrate in the cement paste. A conceptual model of the early hydration process of cement paste with added LAFS was established based on the analytical results. [ABSTRACT FROM AUTHOR]

Efforts are ongoing to utilise agricultural waste to achieve a full resource use approach. Bambara groundnut is an important crop widely grown in the sub-Saharan Africa with potential future importance because of its resilience to thrive under heightened weather uncertainty and widespread droughts that have challenged food security. After harvesting, the edible nuts are separated from the shells which are discarded as waste. Therefore, this research is aimed at characterising the chemical composition and the structural properties of Bambara groundnut shells (BGS) in view of their potential application as a biomass for different bio-products. The chemical composition of BGS was found to be 42.4% cellulose, 27.8% hemicellulose, 13% lignin and 16.8% extractives. Proximate analysis showed a high amount of volatile matter (69.1%) and low moisture (4.4%). XRD analysis confirmed crystallinity of cellulose I polymer and FTIR analysis observed functional groups of lignocellulosic compounds. Thermal stability, maximum degradation temperature and activation energy were found to be 178.5 °C, 305.7 °C and 49.4 kJ/mol, respectively. Compared to other nutshells, BGS were found to have a relatively high amount of cellulose and crystallinity that may result in biocomposites with improved mechanical properties. [ABSTRACT FROM AUTHOR]

Herein, it is demonstrated that a chemical waste from the silicon industry, namely polymethylhydrosiloxane (PMHS), is a suitable hydrosilane source for the challenging, selective aerobic oxidation of olefins into methyl ketones under cobalt catalysis: a first row, abundant in the Earth's crust and cheap metal with low toxicity. The catalytic system operates under unprecedented, stoichiometric amounts of hydrosilane while the cobalt catalyst loading is kept at a very low 1 mol% with the reactions being finished in less than 1 hour with very high turnover numbers (1,340) and record‐breaking turnover frequency values up to 530 h−1. Mechanistic studies highlight the key role of the porphyrin ligand for stabilizing the active cobalt species that does follow a radical‐based reaction pathway under these particular conditions. These results are relevant for replacing the expensive and scarce palladium catalyst, traditionally used for Wacker‐type oxidations, by first‐row, Earth‐abundant transition metals under green conditions including the efficient valorization of a chemical waste such as PMHS. [ABSTRACT FROM AUTHOR]

Cannabinoid extraction during Cannabis processing produces a wax by-product which is currently underutilised, partially because the composition is poorly understood. This study applied both gas and liquid chromatography methods to characterise the major compounds present in the waxy by-product from commercial Cannabis processing. Two industrial wax by-products (wax A and wax B) were used as the feedstock for the characterisation, differing in both strain of Cannabis used and downstream processing conditions. The main classes quantified in the Cannabis waxes were cannabinoids, n-alkanes, fatty alcohols, fatty acids, sterols, and various terpenoids. The cannabinoid fraction was the most abundant fraction in both waxes, reporting a total fraction of 509.3 mg/g for wax A and 392.6 mg/g for wax B, on a solvent-free basis. For wax A the largest remaining wax compound class was the fatty acids, which reported a concentration of 172.2 mg/g, with linoleic acid being the most abundant at a concentration of 68.47 mg/g. The most abundant wax compound class in wax B was the n-alkanes at a concentration of 54.55 mg/g and the dominant species in that fraction was nonacosane (C29) with a concentration of 24.47 mg/g. It can be concluded that due to the high concentration of cannabinoids remaining in the wax even after processing, and their relative commercial value, recovery of the cannabinoids from the wax could form a potential valorisation application for the underutilised Cannabis wax by-product. [ABSTRACT FROM AUTHOR]

Approximately 99% of plastics produced worldwide were produced by the petrochemical industry in 2019 and it is predicted that plastic consumption may double between 2023 and 2050. The use of biodegradable bioplastics represents an alternative solution to petroleum-based plastics. However, the production cost of biopolymers hinders their real-world use. The use of waste biomass as a primary carbon source for biopolymers may enable a cost-effective production of bioplastics whilst providing a solution to waste management towards a carbon–neutral and circular plastics economy. Here, we report for the first time the production of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with a controlled molar ratio of 2:1 3-hydroxybutyrate:3-hydroxvalerate (3HB:3HV) through an integrated pre-treatment and fermentation process followed by alkaline digestion of cassava peel waste, a renewable low-cost substrate, through Cupriavidus necator biotransformation. PHBV was subsequently melt blended with a biodegradable polymer, polycaprolactone (PCL), whereby the 30:70 (mol%) PHBV:PCL blend exhibited an excellent balance of mechanical properties and higher degradation temperatures than PHBV alone, thus providing enhanced stability and controllable properties. This work represents a potential environmental solution to waste management that can benefit cassava processing industries (or other crop processing industries) whilst developing new bioplastic materials that can be applied, for example, to packaging and biomedical engineering. [ABSTRACT FROM AUTHOR]

Coffee is one of the most consumed products globally, and yet its eco-efficiency is still unknown. To address this knowledge gap, this paper examines for the first time the life cycle eco-efficiency of different coffee drinks to identify the most sustainable options and opportunities for improvements in the coffee industry. Nine types of coffee are considered: espresso, latte, cappuccino, Americano, drip-filter, coffee pods, spray-dried and freeze-dried instant, and instant coffee mix. Taking a cradle-to-grave approach, the following life stages are included: coffee cultivation, production and consumption, and end-of-life valorisation of spent coffee grounds. The methodology follows the eco-efficiency ISO 14045 standard to measure the environmental efficiency of a system relative to the economic value it generates. The eco-efficiency is estimated at both the product (one serving) and sectoral (annual consumption) levels based on life cycle assessment (LCA), life cycle costing (LCC) and economic value added (VA). The results show that latte has the highest environmental impacts and LCC but it also has the highest VA at both the product and sectoral levels. Spray-dried instant coffee, on the other hand, has the lowest impacts but also the lowest VA, which makes it the least eco-efficient option. Espresso emerges as the most eco-efficient drink because it has moderate environmental impacts and high VA. Latte and coffee pods are the second most eco-efficient drinks, followed by cappuccino, Americano, and instant coffee mix. Valorising spent coffee grounds could reduce the environmental impacts, LCC and increase the VA at the sectoral level. For example, the climate change impact would be reduced by 80.5–132.1 kt CO2 eq./yr and primary energy demand by 0.9–2.3 PJ/yr while also increasing the VA by £50.2–95 M/yr. When compared to some other food sectors, coffee is 6.4 times more eco-efficient than cheddar cheese and 5.4 times than ice cream and biscuits, respectively. The findings of this study can be used to guide businesses, consumers and policy makers in identifying more eco-efficient coffee products and improving the environmental and economic sustainability of the coffee industry.

This study evaluated the recovery of amorphous calcium phosphate and vivianite from industrial wastewater produced by a toothpaste manufacturing facility, where phosphorus concentrations exceed 3,000 mg L−1. The goal was to reduce the phosphorus concentration on-site to below 20 mg P L−1, so that treated wastewater can be discharged to a municipal wastewater treatment plant. In bench-scale experiments, various dosages of Ca(OH)2 (10–25 g L−1) and FeSO4·7H2O (20–60 g L−1) were evaluated to identify optimal conditions for precipitating >99% of the phosphorus. Pilot-scale experiments showed that recovery of amorphous calcium phosphate required dosing 25 g L−1 Ca(OH)2 and mixing for 60 min, whereas recovery of metavivianite required co-dosing 60 g L−1 FeSO₄·6–7H₂O and 7.2 g L−1 NaOH and mixing for 15 min. Variations in influent wastewater composition were found to significantly affect the pH as well as concentrations of residual Fe2+ and Ca2+ in the treated wastewater. Impurities present in chemicals used for precipitating phosphorus were found to influence purity of the recovered phosphate products. The chemical demand for recovering 99% of the phosphorus in the toothpaste industry wastewater was found to be significantly higher than for recovering 95% of the phosphorus in conventional municipal wastewater. This was due to a higher treatment goal and the unique composition of the wastewater, characterised by its high ionic strength and elevated concentrations of Na+ and Cl−, which potentially inhibited nucleation and crystal growth during chemical precipitation. A preliminary economic analysis indicated that recovering vivianite, with potential applications in the electronics industry, could generate significantly higher profits compared to amorphous calcium phosphate, but this depends on the product purity. Overall, this study highlights the potential for industrial wastewater to contribute to a circular phosphorus economy.

This study evaluates anaerobic bioconversion using landfill-derived microbes to produce volatile fatty acids (VFAs) as bioproducts. The research was conducted using different substrates, including elephant grass, starch waste, and fruit waste. Landfill-derived microbes collected from the landfill site were used as inoculum. The results show that the carbohydrate composition in the substrate affects VFA production. Simpler substrates, such as starch waste and fruit waste, produced more VFAs (approximately 50 mmol · L–1) than that of more complex substrate of grass (approximately 25 mmol · L–1). The results showed that using simpler substrates (i.e. starch and fruit waste) produce VFAs two times higher than that of the complex substrate or lignocellulosic biomass-based feedstock (i.e. grass). These findings provide valuable insights into the potential use of landfill-derived microbes in the anaerobic bioconversion process to produce VFAs. By understanding the influence of carbohydrate composition, we can enhance the efficiency of VFA production from organic waste, which can be used in various industrial applications. This is a crucial step towards more sustainable waste management and more efficient resource utilisation.

Following the goals of the circular economy, this work demonstrates that an industrial by-product can be used in environmental remediation. Metallurgical slag and citric acid were used to form an Fe:Cit complex by simultaneously carrying out the lixiviation of the iron and the chelating stages with an 87% iron recovery. This complex was evaluated in the photo-Fenton process to produce HO• through salicylic acid dosimetry or salicylic acid hydroxylation, producing 0.13 ± 0.1 mM HO• after 30 min of operation; such a value is three orders of magnitude higher than the one reported for the metallurgical slag (as a heterogeneous catalyst, 22 μM) in the photo-Fenton-like process. The system was tested for its ability to degrade a mixture of drugs, including dexamethasone (DEX), naproxen (NAP), and ketorolac (KTR), which are often used to treat the symptoms of COVID-19. The drug degradation tests were performed in two stages. In the first stage, the Fe:Cit complex from the metallurgical slag was compared to the one formed by analytical-grade reactants; the drug degradation was faster for the former, with the major difference being observed at 5 cm and 500 W/m2. Here, 85–90% of the drugs was degraded in 5 min using Fe:Cit from slag, while at least 20 min was necessary to achieve such degradation with the analytical reagent, conceivably because of the trace compounds being lixiviated from the slag. Then, the effects of the liquid depth (5, 10, and 15 cm) and irradiance (250, 500, and 750 W/m2) were tested; the pseudo-first-order kinetic degradation constants for the three model pollutants were in the range of 0.009 > kD > 0.09 min−1, showing that degradation is more feasible for DEX than for NAP and KRT because the radical attack feasibility is related to the molecular structures. [ABSTRACT FROM AUTHOR]

[Display omitted] • Recycling aluminium in a rotary furnace saves great environmental impacts. • Valorising the salt slag instead of landfilling improves LCA indicators by 5–25 %. • The discounted impacts from the secondary aluminium dominate the LCA results. • Other benefits are recovery of NMCs, ammonium sulphate and landfill prevention. • Metal Yield assumptions from 20 to 95 % change the GWP from −3.5 to −17 t CO 2 eq. Recycling aluminium in a rotary furnace with salt-fluxes allows recovering valuable alloys from hard-to-recycle waste/side-streams such as packaging, dross and incinerator bottom ash. However, this recycling route generates large amounts of salt-slag/salt-cake hazardous wastes which can pose critical environmental risks if landfilled. To tackle this issue, the metallurgical industry has developed processes to valorise the salt-slag residues into recyclable salts and aluminium concentrates, while producing by-products such as ammonium sulphate and non-metallic compounds (NMCs), with applications in the construction or chemical industries. This study aims to assess through LCA the environmental impacts of recycling aluminium in rotary furnaces for both salt-slag management routes: valorisation or landfill. It was found that this recycling process brings forth considerable net environmental profits, which increase for all the considered impact categories if the salt-slag is valorised. The main benefits arise from the production of secondary cast aluminium alloys, which is not unexpected due to the high energy intensity of aluminium primary production. However, the LCA results also identify other hotspots which play a significant role, and which should be considered for the optimisation of the process based on its environmental performance, such as the production of by-products, the consumption of energy/fuels and the avoidance of landfilling waste. Additionally, the assessment shows that the indicators for mineral resource scarcity, human carcinogenic toxicity and terrestrial ecotoxicity are particularly benefited by the salt-slag valorisation. Finally, a sensitivity analysis illustrates the criticality of the metal yield assumptions when calculating the global warming potential of aluminium recycling routes. [ABSTRACT FROM AUTHOR]

Global concern about plastic pollution is forcing new policies and modifications of human consumption as well as promoting new research lines aiming at the replacement of non-degradable plastics with other polymers more environmentally friendly. Addressing food waste and promoting circular economy strategies, among other approaches, are crucial in reducing environmental impacts and fostering sustainability in several sectors like the agri-food industry. The European Union’s Circular Economy Action Plan is a significant initiative in this direction. Biotechnological processes, especially the valorisation of agri-food waste to produce highly marketed biomolecules like poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) using microorganisms as cellular factories, offer promising avenues for achieving these goals. PHBV is a biodegradable polymer firstly characterised as an isolated biopolymer from bacterial biomass. This biopolymer shows interesting physicochemical properties making possible immense potential in various applications due to its biocompatibility and sustainability, thus revealing it as a good candidate to replace plastics produced by chemical synthesis from petroleum (which are highly recalcitrant and consequently pollutants). This review critically analyses the PHBV synthesis and end-of-life scenarios from their synthesis using chemical and biological pathways, through the forms of biotechnological operation and production, to the forms described until the moment of recycling. [ABSTRACT FROM AUTHOR]

Metal nanoparticles (MNPs) have gained significant attention due to their multifunctional properties and broad applications in various fields. In this study, we present a novel and sustainable approach for the synthesis of silver nanoparticles (AgNPs) using waste materials, dried banana pith extract (BPE) and rice water. The synthesised AgNPs exhibit a size of 43 nm and zeta potential of −24.1 mV. A maximum temperature rise of 4°C with an efficiency of 41% is achieved within a short time by the photothermal activity. The qualitative colorimetric detection of Fe3+ and its quantitative spectroscopic detection are achieved in a linear detection range of 20–80 μM and with a limit of detection of 8.5 μM. The sensing mechanism is explained in terms of cooperative binding of Fe3+ ions to BPE-AgNPs. A homogeneous, flexible and stable AgNP-rice starch gel is formed. The work offers environmentally conscious nanomaterials for diverse applications. [ABSTRACT FROM AUTHOR]

• The black soldier fly links sustainable protein production and waste valorisation. • Larval diet impacts development time, lifespan, adult body size and egg production. • Spent Brewer's grains resulted in the best performing flies. • Even flies on low-nutritious larval diets produced fertile eggs. The interest in mass-rearing black soldier fly (Hermetia illucens) larvae for food and feed is rapidly increasing. This is partly sparked by the ability of the larvae to efficiently valorise a wide range of organic waste and by-products. Primarily, research has focused on the larval stage, hence underprioritizing aspects of the adult biology, and knowledge on reproduction-related traits such as egg production is needed. We investigated the impact of different organic waste and by-products as larval diets on various life-history traits of adult black soldier flies in a large-scale experimental setup. We reared larvae on four different diets: spent Brewer's grain, ground carrots, Gainesville diet, and ground oranges. Traits assessed were development time to pupa and adult life-stages, adult body mass, female lifespan, egg production, and egg hatch. Larval diet significantly impacted development time to pupa and adult, lifespan, body size, and egg production. In general, flies reared on Brewer's grain developed up to 4.7 d faster, lived up to 2.3 d longer, and produced up to 57% more eggs compared to flies reared on oranges on which they performed worst for these traits. There was no effect of diet type on egg hatch, suggesting that low-nutritious diets, i.e. carrots and oranges, do not reduce the quality but merely the quantity of eggs. Our results demonstrate the importance of larval diet on reproductive output and other adult traits, all important for an efficient valorisation of organic waste and by-products, which is important for a sustainable insect-based food and feed production. [ABSTRACT FROM AUTHOR]

Agricultural plantations in Indonesia and Malaysia yield substantial waste, necessitating proper disposal to address environmental concerns. Yet, these wastes, rich in starch and lignocellulosic content, offer an opportunity for value-added product development, particularly amino acid production. Traditional methods often rely on costly commercial enzymes to convert biomass into fermentable sugars for amino acid production. An alternative, consolidated bioprocessing, enables the direct conversion of agricultural biomass into amino acids using selected microorganisms. This review provides a comprehensive assessment of the potential of agricultural biomass in Indonesia and Malaysia for amino acid production through consolidated bioprocessing. It explores suitable microorganisms and presents a case study on using Bacillus subtilis ATCC 6051 to produce 9.56 mg/mL of amino acids directly from pineapple plant stems. These findings contribute to the advancement of sustainable amino acid production methods using agricultural biomass especially in Indonesia and Malaysia through consolidated bioprocessing, reducing waste and enhancing environmental sustainability. [ABSTRACT FROM AUTHOR]

The production of mineral fertilisers relies heavily on mineral deposits that are becoming depleted or is based on processes that are highly energy demanding. In this context, and in line with the circular economy and the European Green Deal, the recovery of nitrogen (N), phosphorus (P), and potassium (K) from organic wastes using chemical technologies is an important strategy to produce secondary raw materials for incorporation into mineral fertilisers, partially replacing the traditional sources of N, P, and K. However, there are very few studies on the agronomic and environmental effects of such substitution. The aim of this work was to evaluate plant growth under microcosm conditions and the effect on the soil microbiome of mineral fertilisers in which part of the N, P, or K content comes from bio-based materials (BBMFs), namely ash, struvite, and a patented chemical process. The crop was maize, and a metataxonomic approach was used to assess the effect on the soil microbiome. The BBMF treatments were compared with a control treated with a conventional mineral fertiliser. The conventional fertiliser performed significantly better than the bio-based fertilisers in terms of maize biomass production at the first sampling point 60 days after sowing (DAS), but at the last sampling point, 90 DAS, the BBMFs showed comparable or even better biomass production than the conventional one. This suggests that BBMFs may have a slightly slower nutrient release rate. The use of fertiliser, whether conventional or BBMF, resulted in a significant increase in microbiome biodiversity (Shannon index), while it did not affect species richness. Interestingly, the use of fertilisers modulated the composition of the bacterial community, increasing the abundance of beneficial bacterial taxa considered to be plant-growth-promoting bacteria, without significant differences between the conventional mineral fertilisers and the BBMFs. The predominance of PGPRs in the rhizosphere of crops when BBMFs are used could be part of the reason why BBMFs perform similarly or even better than conventional fertilisers, even if the rate of nutrient release is slower. This hypothesis will be tested in future field trials. Thus, BBMFs are an interesting option to make the food chain more sustainable. [ABSTRACT FROM AUTHOR]

Extractions of cashew nut shell liquid (CNSL) have always widely been carried out with non-environmentally friendly solvents. Hence, greener solvents are desired as alternative to currently used solvents. Herein, batch extractions of Nigerian CNSL with greener solvents: ethyl acetate and cyclohexane mixture in different ratios were investigated in hot and cold system and results compared with conventional solvent (petroleum ether). Compositional studies of the extracted CNSL and its isolated components were done with Fourier-Transformed Infrared (FTIR), Nuclear Magnetic Resonance (NMR) spectroscopy and Ultra High-Performance Liquid Chromatography-Mass Spectrometry (UHPLC-MS). Cost effectiveness analysis for the extraction solvents and methods was also investigated. It was revealed that ethyl acetate and ethyl acetate-cyclohexane mixture at cold and hot conditions recorded higher CNSL yields than previous reports even at a lower liquid-to-solid ratio. Chemical composition and component quantity extracted did not significantly change under hot or cold system. The present composition of the Nigerian CNSL contains unusually higher amount of anarcardic acid (79 %) and cardanol (14 %) than ever reported. Additionally, degree of unsaturation in the alkyl chain of the CNSL is in the order triene>monoene>diene in the anarcardic acid and cardanol components of the liquid. Cost effectiveness analysis at a kilogramme scale revealed that the order of greenness of extraction route based on solvent type, energy requirement and condition of extraction is ethyl acetate-solvent cold system> ethyl acetate-hot system> ethyl acetate-cyclohexane-system> cyclohexane system > pet. ether system.

This research evaluates the economic and environmental feasibility of extracting dietary fibre (DF) from a by-product such as soybean hulls. Techno-economic (TEA) and life cycle assessment (LCA) were carried out to identify the critical factors that may limit the implementation of a potential biorefinery plant. The modelling of the process was carried out on the basis of mass and energy balances, as well as the characteristics of the required equipment. TEA indicators such as minimum selling price (MSP), fixed capital investment, manufacturing costs were evaluated. A cradle-to-gate LCA approach and a functional unit (FU) of 1 kg of product (85% DF content) were considered. Impact categories such as global warming (GW), eutrophication, eco-toxicity, among others, were analysed. The results indicate that the production capacity achieves the plateau at about 56 kt y−1, with an MSP value of 2.6 $·kg−1. Furthermore, the GW profile was 8.76 kg CO2eq per FU, and the main hotspot is the alkaline digestion stage due to the use of potassium hydroxide (KOH). Nevertheless, the management of the hulls from multi-product food plants and switching KOH production to renewable sources may reduce the profile in almost all categories analysed.

Fruit and vegetable industrialisation is a major contributor to food waste; thus, its integral transformation into functional powders has gained attention. Pretreatments can be incorporated into valorisation processes to generate structural or biochemical changes that improve powders’ characteristics. This study deepens into the impact of biological (fermentation, FERM) and thermophysical (autoclaving, AUTO; microwaves, MW; ultrasound, US; and pasteurisation, PAST) pretreatments, combined with dehydration (hot air-drying, HAD; or freeze-drying, FD) on the characteristics of powdered products obtained from broccoli stems. The impact of pretreatments on physicochemical (moisture, water activity, total soluble solids) and antioxidant properties (phenols, flavonoids, antioxidant capacity by ABTS and DPPH) on residue and powdered products was studied, together with their impact on plant tissue structure (Cryo-SEM) and the powders’ phenolic profile (HPLC). Probiotic viability was also determined on the fermented samples. The pretreatments applied, particularly the ultrasound, improved the antioxidant properties of the broccoli stems compared to the unpretreated samples, in line with microscopic observations. Dehydration did also improve the antioxidant attributes of the broccoli wastes, especially drying at 60 °C. However, pretreatments combined with dehydration did not generally lead to an improvement in the antioxidant properties of the powders. Probiotic properties were preserved in the freeze-dried products (>107 CFU/g). In conclusion, pretreatments may be applied to enhance the antioxidant attributes of broccoli wastes, but not necessarily that of dried powdered products.

Over 50 MioT of Waste Cooking Oil (WCO) was collected worldwide in 2020 from domestic and industrial activities, constituting a potential hazard for both water and land environments, and requiring appropriate disposal management strategies. In line with the principles of circular economy and eco-design, in this paper an innovative methodology for the valorisation of WCO as a rejuvenating agent for bitumen 50/70 coming from Reclaimed Asphalt Pavement (RAP) is reported. In particular, WCO or hydrolysed WCO (HWCO) was modified by transesterification or amidation reactions to achieve various WCO esters and amides. All samples were characterised by nuclear magnetic resonance, melting, and boiling point. Since rejuvenating agents for RAP Cold Mix Asphalt require a melting point ≤0 °C, only WCO esters could further be tested. Efficiency of WCO esters was assessed by means of the Asphaltenes Dispersant Test and the Heithaus Parameter. In particular, bitumen blends containing 25 wt% of WCO modified with 2-phenylethyl alcohol, showed high dispersing capacity in n-heptane even after a week, compared to bitumen alone (1 h). Additionally, the Heithaus Parameter of this bitumen blend was almost three times higher than bitumen alone, further demonstrating beneficial effects deriving from the use of WCO esters as rejuvenating agents. [ABSTRACT FROM AUTHOR]

The rapid increase in solid waste along with urbanisation, especially arising from the industrial and agricultural sectors, sparks concern from the public regarding their adverse impact on human and environmental wellness. Therefore, waste biorefinery is the current interest that aligns with the concept of 'waste-to-wealth'. The conversion of waste into valuable products such as cellulose nanocrystals (CNCs) is an alternative method of circular waste management as CNCs have various applications. Their non-toxicity, biocompatibility, excellent mechanical strength, and load-bearing properties render them a good reinforcement agent for packaging films, sensors, and scaffolds. Nonetheless, the lack of studies on the comparison of waste sources and the complex parameters for the extraction of CNCs hinders the development of CNC extraction from waste products. This review paper compares and organizes the information from previously published scientific papers and reports on waste product sources, methods, parameters, and environmental effects of the derivation of CNCs from waste. Previously, no thorough reviews have been done closely on the sustainability aspect of CNC extraction from waste products. Through this review, it shows that there is a positive trend where novel CNC extraction routes are discovered to improve the yield, environmental friendliness, performance, and cost. However, most of the studies did not specify the environmental impacts of the extraction routes, limiting their feasibility for conventional applications. [ABSTRACT FROM AUTHOR]