Upcycling Of Waste Research Articles

Challenges and Technological Requirements in Agri-Food Waste Upcycling: the Case Study of Olive Leaf Extract

Challenges and Technological Requirements in Agri-Food Waste Upcycling: the Case Study of Olive Leaf Extract

Biodegradability of tomato stem-reinforced composites: Towards a virtuous approach to local and circular waste upcycling

Biodegradability of tomato stem-reinforced composites: Towards a virtuous approach to local and circular waste upcycling

Development of a Facile and Green Synthesis Strategy for Brightly Fluorescent Carbon Dots from Various Waste Materials.

Carbon dots (CDs) are fluorescent carbon-based nanomaterials with remarkable properties, making them more attractive than traditional fluorophores. Consequently, researchers focused on their development and application in fields such as sensing and bioimaging. One potential advantage of employing CDs is using organic waste as carbon precursors in their synthesis, providing a pathway for waste upcycling for a circular economy. However, waste-based CDs often have low fluorescence quantum yields (QYFL), limiting their practical applications. So, there is a need for a well-defined strategy to consistently produce waste-based CDs with appreciable QYFL, irrespective of the starting waste material. Herein, we developed a fabrication strategy based on the hydrothermal treatment of waste materials, using citric acid as a co-carbon precursor and ethylenediamine as N-dopant. This strategy was tested with various materials, including corn stover, spent coffee grounds, cork powder, and sawdust. The results showed consistently appreciable QYFL, reaching up to ~40 %. A Life Cycle Assessment (LCA) study demonstrated that producing these waste-based CDs has lower environmental impacts compared to CDs made solely from commercial reagents. Thus, we have established a framework for the environmentally friendly production of CDs by upcycling different waste materials without significant sacrifices in performance (QYFL).

A chemoenzymatic cascade for sustainable production of chiral N-arylated aspartic acids from furfural and waste

Both biomass valorization and waste upcycling are important routes to sustain the circular bioeconomy. In this work, we present a chemoenzymatic cascade for selective synthesis of chiral N-arylated aspartic acids from biomass-derived furfural and waste nitrophenols (NPs) by merging robust photo- and electrocatalysis with stereoselective biocatalysis. Concurrent photoelectrocatalytic oxidation of furfural into maleic acid (MA) and fumaric acid (FA) was significantly enhanced by combining catalyst and reaction engineering strategies including identification of a powerful photocatalyst meso-tetra(4-carboxyphenyl)porphyrin, continuous flow technique, enhancing dissolved O2 and paired electrosynthesis. The overall space-time yield (STY) approached 2.8 g L−1 h−1 in a fed-batch process, with the product titer of 28.3 g L−1. Besides, photoelectrosynthesis of MA/FA was effectively fueled by sunlight, with the STY of up to 3.6 g L−1 h−1. Both MA selectivity and yield could be facilely improved to around 89% by reducing the buffer concentrations. Paired electrosynthesis strategy not only resulted in greatly improved MA production at the anode, but also enabled NPs upcycling into value-added aminophenols (APs) at the cathode. The products formed in the two electrode chambers were converted into N-arylated (S)-aspartic acids by a bienzymatic cascade. This work presents a multicatalytic approach for integrating selective biomass valorization and waste upcycling towards sustainable manufacture.

Metabolic engineering of Escherichia coli for upcycling of polyethylene terephthalate waste to vanillin.

Polyethylene terephthalate (PET) waste presents a significant environmental challenge due to its durability and resistance to degradation. Innovative approaches for upcycling PET waste into high-value chemicals can mitigate these issues while contributing to a circular economy. In this study, we developed a multi-enzyme cascade system in E. coli to convert PET-derived monomer terephthalic acid (TPA) into vanillin (VAN). The metabolic engineering approach was then employed to increase VAN production, including 1) inhibition of VAN degradation by knocking out endogenous aldehyde reductases and alcohol dehydrogenases and 2) enhancement of TPA uptake by modifying membrane proteins to increase cell permeability. The engineered E. coli demonstrated a VAN production of 658.55mg/L from 1992mg/L of TPA with a molar conversion rate of 71.1%, representing the highest production of VAN using TPA as the substrate. Additionally, the engineered E. coli effectively converted post-consumer PET waste into VAN under mild conditions, with the highest production of 259.2mg/L in 20× diluted PET hydrolysates, highlighting its potential for application in PET waste upcycling. This approach not only provides an environmentally friendly alternative to traditional chemical synthesis but also offers substantial economic benefits by transforming low-value waste into high-value chemicals.

Dirty, difficult and dangerous: Establishing a plastics waste upcycling system in Nepal

Dirty, difficult and dangerous: Establishing a plastics waste upcycling system in Nepal

Waste upcycling of Sapota peels as a green route for the synthesis of silver nanoparticles and their application as catalytic and colorimetric detection of Co2+ and Hg2+

Biochemical synthesis of nanoparticles (NPs) using plant part extracts as capping and reducing agents has drawn considerable attention in research with a growing focus on green chemistry. The present study utilized Sapota (Manilkara zapota L.) peel extract to synthesize silver nanoparticles (SP-AgNPs) using ultrasonic vibration. Different characterization techniques such as UV-vis spectroscopy, dynamic light scattering, Fourier Transform Infrared Spectroscopy, Field emission scanning electron microscope, High resolution transmission electron microscopy, and X-ray diffraction were employed to check the production of SP-AgNPs. The AgNPs were crystalline in nature and had an average particle size of 27.906 nm. The research primarily focused on two aspects: the catalytic activity of SP-AgNPs in degrading environmental pollutants and their ability to act as colorimetric sensors for toxic metal ions. SP-AgNPs exhibited significant catalytic activity in the decomposition of various pollutants such as Methyl Orange (0.035 ± 0.090 min−1, 92.89 ± 1.79%), Crystal Violet (0.1097 ± 0.1016 min−1, 85.56 ± 2.21%) and Cosmic Brilliant Blue G-250 (0.0697 ± 0.0275 min−1, 79.56 ± 1.80%). The high degradation percentages and reaction rate constants indicate the efficiency of SP-AgNPs in pollutant degradation. Additionally, the study demonstrated the effectiveness of SP-AgNPs as sensors for detecting toxic metal ions, particularly Co2+ and Hg2+ with limits of detection 54.40 ± 1.43 µM and 10.70 ± 0.16 µM. With impressive sensitivity and low detection limits, SP-AgNPs showed promise in detecting these ions, which are often found in environmental contaminants. Moreover, their plant-based synthesis, low toxicity, and cost-effectiveness make them attractive options for environmental remediation efforts.Graphical abstract

Lightweight aggregates produced from low-temperature sintering of multiple solid wastes for heavy metals removal: Adsorption kinetics and stabilization

Solid wastes, including incinerated sewage sludge ash (ISSA), waste bentonite, and waste glass powder (WGP), were recycled and sintered at a low temperature (680 °C) to produce lightweight aggregates (WSA). WGP acted as a fluxing agent to significantly lower sintering temperature of 1000–1200 °C in other studies. WSA demonstrated an excellent mechanical strength of 3.76 MPa. The adsorbent dosage, initial pH, kinetics and isotherm on heavy metals adsorption were evaluated in batch adsorption experiments. The isothermal data exhibited a good correlation with the Langmuir model, and the maximum adsorption capacity was approximately 9.26 mg/g at 296 K. Pb(II) removal was dominated by precipitation and cation exchange. Breakthrough curves were determined for fixed-bed adsorption. At 50% breakthrough, the maximum adsorption capacity was 1.82 mg/g. The WSA after heavy metals adsorption were then reused to replace river sand (10–50%) in producing lightweight mortars. The solidification of spent WSA in the lightweight mortars could significantly reduce the leaching of Pb(II) by 98.5%. Moreover, the reuse of spent WSA resulted in low density and low thermal conductivity of cement mortars. This study demonstrates total waste management for municipal solid wastes: upcycling of waste–utilization–permanently stored as construction materials.

Upcycling of waste polyethylene terephthalate (PET) into CoFe@C for highly efficient PV-driven bifunctional seawater splitting via a “waste materialization” strategy

Developing green and efficient techniques to convert plastic wastes into functional materials is attractive and remains highly challenging. This study employs a hydrothermal combining with pyrolysis process for constructing a Co3Fe1@C heterostructure from the polyethylene terephthalate (PET) waste-mediated metal-organic frameworks. The as-obtained Co3Fe1@C shows a core-shell structure and possesses good performance towards water electrolysis. The Co3Fe1@C can attain the current density of 100 mA cm−2 with an overpotential of 250 mV for oxygen evolution reaction (OER). In addition, the bifunctional Co3Fe1@C can realize the overall seawater electrolysis at 50 mA cm−2 with good stability for 280 h driven by a 2.2 V commercial silicon solar cell. Overall, this study demonstrates a green chemistry approach to simultaneous plastic waste upcycling and cost-effective electrocatalyst fabrication, which may stimulate further research on the “waste materialization” approach to converting solid waste into highly efficient catalysts for various chemistry and energy industry applications.

Upcycling of Food By-Products and Waste: Nonthermal Green Extractions and Life Cycle Assessment Approach

Food loss and waste constitute a substantial threat to global food system sustainability, representing 38% of energy consumption in the supply chain. The 2030 Agenda for Sustainable Development highlights a vision integrating social, economic, and environmental pillars. Addressing environmental impact requires recycling (destruction for new creations) and upcycling (converting waste into valuable products). This review highlights nonthermal green extractions and sustainable techniques in upcycling raw materials such as olives, red beetroot, sugar beet, and coffee, which are widely used in the food industry. Nonthermal processing efficiently extracts bioactive compounds and utilizes waste. Key approaches for its valorization include life cycle assessment, environmental footprint analysis, energy efficiency strategies, digitalization, and sustainability considerations. However, challenges remain in calculating their environmental impact. Waste and by-product valorization from raw materials address disposal issues, offering economic and environmental benefits. Nonthermal techniques show optimistic opportunities in green extraction and sustainable upcycling. The focus is on raw materials including olives, red beetroot, sugar beet, and coffee byproducts, and possible product development. There are powerful connections offering industry tools for impactful sustainability management and guiding decisions on waste-to-value or ‘upcycling’ products. The review contributes to filling the gap in usage of nonthermal processing in upcycling of waste and by-products.

Stirring digital innovation in wood waste upcycling: system dynamics as a circular design decision-making methodology

Abstract The urgency to reduce climate-changing emissions and natural resources exploitation is pushing architecture and industrial design to explore viable options to innovate current practices on material use. In forest-based industries, in particular, wood upcycling is emerging as a pivotal investigation field, with a specific research agenda aimed at reducing the impacts generated by the rising demand of timber products and the actual incineration and landfilling rates. Indeed, the development of new technological solutions needs to account for energy and material flows, as well as for the environmental impacts and social and economic dynamics. Such a new complexity pushes towards a design approach that links digital technologies to circularity goals for a more comprehensive understanding of the forest-based resource management and the evalutation of alternative scenarios. In this paper, we propose System Dynamics (SD) as a methodology to provide a qualitative and quantitative framework to promote digital circular innovation in the wood industry. SD is a dynamic, multi-scale, multi-dimension and site-specific decision-making support tool wich helps designers, researchers and industrial stakeholders to understand and simulate the dynamic behavior and performances of complex systems within specific time and space parameters. The proposed SD for wood waste upcycling allows to model “stock and flow” scenarios, to simulate and compare the consequences of technological options on the system and to target their development in time - and space-based projections. This study outlines the first advances for the SD application to the Italian wood industry, and examines the consequences of the application of different circular strategies on a “business-as-usual” scenario.

Catalytic pyrolysis upcycling of waste thermosetting epoxy resin into fire‐retardant additive

AbstractThis research introduces a low‐temperature catalytic‐assisted pyrolysis method for recycling waste thermosetting epoxy resins, transforming them into an efficient fire‐retardant additive for new epoxy resin formulations. In this study, we demonstrate that boric acid (BA) can significantly reduce the temperature required for epoxy resin (EP) pyrolysis, resulting in degradation products containing boron atoms that can act as a fire‐retardant additive. The impact of 5%–20% content of recycled EP (R‐EP) on the curing process, thermal stability, fire retardancy, and mechanical properties of the new EP was comprehensively investigated. The TGA results show that adding BA to epoxy resin at a 1:4 BA:EP ratio significantly reduces pyrolysis temperature. Neat EP degrades in two stages in 341°C and 557°C, while EP with BA degrades in three stages, starting below 120°C and peaking around 142°C. The results demonstrated an outstanding effect of incorporating 20% R‐EP on the char formation and fire retardancy of the new EP, surpassing the performance of 20% triphenyl phosphate (TPP), a commercially available fire retardant. The storage modulus for neat EP is 1510 MPa, increasing to 2280 MPa with EP/R‐EP 20%, indicating enhanced rigidity. Addition of R‐EP raised glass transition temperature (Tg) of the epoxy resin up to 38°C, indicating highly cross‐linked structures compared to TPP‐modified EP, which shows lower Tg values.

Correction: Upcycling of waste masks into carbon nanotubes combined with ZIF-8 for the detection of heavy-metal ions and nitrite

Correction: Upcycling of waste masks into carbon nanotubes combined with ZIF-8 for the detection of heavy-metal ions and nitrite

Elemental content and safety evaluation of wild-harvested Australian abalone (Haliotis spp.) viscera: Addressing safety concerns in food waste upcycling

Abalone viscera has been shown to be a valuable human nutraceutical, yet the food safety considerations of consuming whole abalone viscera have been largely overlooked. Hence, this research was conducted to investigate and evaluate elemental compositions and safety of it. The elemental data was compared to international food safety regulations and evaluated using the USEPA hazard index (HI) equation and HI-derived estimated upper limit (EDUL) equation, which EDUL allows comparison of novel foods with a large variety of similar existing products. To further demonstrate that food safety of upcycled food could be improved with simple processing, a risk mitigation trial was conducted. The results indicated that whilst heavy metal levels (mg/kg) and HI were shown to reach unsatisfactory food safety levels, this exceedance was likely caused by overestimation in daily consumption. The EDUL results supported this explanation and demonstrated that abalone viscera posed no safety concern even when eaten in quantities similar to common shellfish. The risk mitigation trial was as well successful, demonstrating up to 32 % reduction in HI. The findings identified options to evaluate and improve safety of novel food and can be a case study to evaluate, understand and overcome food safety challenges in other upcycled food.

Electrocatalytic upcycling of plastic waste: Progress, challenges, and future

AbstractThe escalating accumulation of plastic waste has been developed into a formidable global environmental challenge. Traditional disposal methods such as landfilling and incineration not only exacerbate environmental degradation by releasing harmful chemicals and greenhouse gases, but also squander finite resources that could otherwise be recycled or repurposed. Upcycling is a kind of plastic recycling technology that converts plastic waste into high‐value chemicals and helps to avoid resource waste and environmental pollution. Electrocatalytic upcycling emerges as a novel technology distinguished by its mild operational conditions, high transformation efficiency and product selectivity. This review commences with an overview of the recycling and upcycling technology employed in plastic waste management and the respective advantages and inherent limitations are also delineated. The different types of plastic waste upcycled by electrocatalytic strategy are then discussed and the plastic waste transformation process is examined together with the mechanisms underlying the electrocatalytic upcycling. Furthermore, the structure‐activity relationships between electrocatalysts and plastic waste upcycling performance are also elucidated. The review aims to furnish readers with a comprehensive understanding of the electrocatalytic techniques for plastic waste upcycling and to provide a guidance for the design of electrocatalysts towards efficient plastic waste transformation.

WITHDRAWN: Elemental content and safety evaluation of wild-harvested Australian abalone (Haliotis spp.) viscera: addressing safety concerns in food waste upcycling.

Abalone viscera has shown to be a valuable human nutraceutical, yet the food safety considerations of consuming whole abalone viscera have been largely overlooked. Hence, this research was conducted to investigate and evaluate elemental compositions and safety of it. The elemental data was compared to international food safety regulations and evaluated using the USEPA hazard index (HI) equation and HI-derived estimated upper limit (EDUL) equation, which EDUL allows comparison of novel foods with a large variety of similar existing products. To further demonstrate that food safety of upcycled food could be improved with simple processing, a risk mitigation trial was conducted. The results indicated that whilst heavy metal levels (mg/kg) and HI were shown to reach unsatisfactory food safety levels, this exceedance was likely caused by overestimation in daily consumption. The EDUL results supported this explanation and demonstrated that abalone viscera posed no safety concern even when eaten in quantities similar to common shellfish. The risk mitigation trial was as well successful, demonstrating up to 32 % reduction in HI. The findings identified options to evaluate and improve safety of novel food and can be a case study to evaluate, understand and overcome food safety challenges in other upcycled food.

Expanded polystyrene (EPS) waste upcycling and efficient oil/water emulsion separation with advanced EPS-cotton membranes

The current work describe the fabrication of an oleophilic and hydrophobic EPS-cotton membrane through a facile one-step process, involving the immersion of pristine cotton fabric in a freshly prepared solution of EPS in tetrahydrofuran (THF). The characterization of EPS-cotton membrane is carried out using FTIR spectroscopy, scanning electron microscopy (SEM), and contact angle measurements. The EPS-cotton membrane exhibits remarkable absorption capacity for diesel, gasoline, olive oil, and canola oil, i.e., 0.21 gg−1, 0.13 gg−1, 3.7 gg−1 and 0.40 gg−1, respectively. Using vacuum filtration, the membrane effectively segregates diesel oil, gasoline, olive oil, and canola oil emulsions from water. The flux of membrane for diesel oil, gasoline, olive oil, and canola oil emulsions with water is found to be 133 LMH, 207 LMH, 59 LMH and 89 LMH, respectively. Moreover, the water rejection (%) remains above 95 % in all cases. The separated samples are monitored through FTIR and UV/Vis, which suggests high separation efficiency of EPS-cotton membrane. Furthermore, FTIR and SEM analyses of EPS-cotton membrane before and after separations demonstrate suitable membrane stability, allowing for at least six cycles of effective use. EPS-cotton membrane fabrication not only facilitates the eco-friendly recycling of waste plastics but also promises versatile applications in environmental remediation.

Upcycling of waste masks into carbon nanotubes combined with ZIF-8 for the detection of heavy-metal ions and nitrite

Upcycling of waste masks into carbon nanotubes combined with ZIF-8 for the detection of heavy-metal ions and nitrite

A Review of Grease Trap Waste Management in the US and the Upcycle as Feedstocks for Alternative Diesel Fuels

As byproducts generated by commercial and domestic food-related processes, FOGs (fats, oils, and grease) are the leading cause of sewer pipe blockages in the US and around the world. Grease trap waste (GTW) is a subcategory of FOG currently disposed of as waste, resulting in an economic burden for GTW generators and handlers. This presents a global need for both resource conservation and carbon footprint reduction, particularly through increased waste upcycling. Therefore, it is critical to better understand current GTW handling practices in the context of the urban food–energy–water cycle. This can be accomplished with firsthand data collection, such as onsite visits, phone discussions, and targeted questionnaires. GTW disposal methods were found to be regional and correspond to key geographical locations, with landfill operations mostly practiced in the Midwest regions, incineration mainly in the Northeast and Mid-Atlantic regions, and digestion mainly in the West of the US. Select GTW samples were analyzed to evaluate their potential reuse as low-cost feedstocks for biodiesel or renewable diesel, which are alternatives to petroleum diesel fuels. Various GTW lipid extraction technologies have been reviewed, and more studies were found on converting GTW into biodiesel rather than renewable diesel. The challenges for these two pathways are the high sulfur content in biodiesel and the metal contents in renewable diesel, respectively. GTW lipid extraction technologies should overcome these issues while producing minimum-viable products with higher market values.

Valorization of Food Waste: Utilizing Natural Porous Materials Derived from Pomelo-Peel Biomass to Develop Triboelectric Nanogenerators for Energy Harvesting and Self-Powered Sensing.

Food waste is an enormous challenge, with implications for the environment, society, and economy. Every year around the world, 1.3 billion tons of food are wasted or lost, and food waste-associated costs are around $2.6 trillion. Waste upcycling has been shown to mitigate these negative impacts. This study's optimized pomelo-peel biomass-derived porous material-based triboelectric nanogenerator (PP-TENG) had an open circuit voltage of 58 V and a peak power density of 254.8 mW/m2. As porous structures enable such triboelectric devices to respond sensitively to external mechanical stimuli, we tested our optimized PP-TENG's ability to serve as a self-powered sensor of biomechanical motions. As well as successfully harvesting sufficient mechanical energy to power light-emitting diodes and portable electronics, our PP-TENGs successfully monitored joint motions, neck movements, and gait patterns, suggesting their strong potential for use in healthcare monitoring and physical rehabilitation, among other applications. As such, the present work opens up various new possibilities for transforming a prolific type of food waste into value-added products and thus could enhance long-term sustainability while reducing such waste.