Waste Valorization Research Articles

Pasta Enriched with De-oiled Sesame and Yellow Pepper Flours: Evaluation of Physicochemical Properties, Protein Quality, and Antioxidant Potential

Valorization of waste as a sustainable food additive to produce value-added products is a recent interest. De-oiled sesame flour (DSF) is underutilized despite its rich protein, fiber, and phenols content. Pasta has a poor nutritional value but is a good vehicle for fortification. Therefore, pasta was enriched with DSF at 10%, 20%, and 30%, in addition to 5% yellow pepper flour (YPF) to improve the taste (S10, S20, and S30, respectively). The enriched pasta was compared to control pasta (S0) made from 100% durum wheat semolina concerning the sensory attributes, cooking quality, physicochemical properties, and microstructure. S20 pasta demonstrated good cooking properties and a texture profile similar to the control, with high sensory appeal. It had the lowest cooking loss (7.60±0.10), gumminess (39.50±5.12 g), and chewiness (0.62±0.09 mJ), the highest water absorption and volume expansion (101.30±1.27% and 295.00±7.07%), a shorter cooking time (10.05±0.71 min) and hardness (73.00±5.66 g), with a moderate cohesiveness (0.54±0.03) (p<0.05). DSF increased the protein content of the enriched pasta significantly compared to the control (14.40±0.57g to 16.90±0.57g versus 13.20±0.28 g/100g). Besides, the protein quality was improved by adding 20% DSF: The essential amino acid index increased from 62.76±0.05% to 73.11±0.95% in S20 (p<0.05). Furthermore, the antioxidant activity was increased from 1.67±2.12% (control) to 28.75±1.53% (S20) (p<0.05). Besides, iron, calcium, and zinc were increased considerably (p<0.05). De-oiled sesame flour at 20% (S20) is a promising additive for pasta producers that offers acceptable physical changes, high nutritional value, and enhanced protein quality compared to control.

Plastic Waste Valorization: Prospects for Green Hydrogen Production

: Plastic waste is a current issue worldwide that is already negatively influencing and threatening the lives of human beings, with residual micro- and nanoplastics entering water and soil bodies inducing recalcitrant pollution and health issues. The proposed perspective has been aimed to provide an overview of the potential of plastic waste valorization to green hydrogen and carbonaceous nanostructures. The overall concept additionally includes the utilization of the generated carbonaceous nanostructures to design advanced functional materials in combination with the obtained green hydrogen from plastic waste in a number of batch-to-flow catalytic hydrogenations to close the circle of sustainable integrated valorization of plastic waste. The concept also includes insightful Life-Cycle Assessment (LCA) and techno-economic studies in order to select the most relevant lines from the sustainability and cost-competitive standpoints.

Sustainable syngas production from thermochemical processing of cellulosic textile waste in the presence of CO2

In response to ever-expanding textile industry, substantial generation in clothing waste has posed the environmental risks caused by conventional treatments. As an alternative approach, this study aims to establish pyrolytic valorisation of cellulosic textile waste. To impart sustainability to the pyrolysis system, a novel approach was proposed by employing carbon dioxide (CO2), key greenhouse gas, as reactive feedstock. This study mainly investigated mechanical function of carbon dioxide on all pyrogenic products derived from cellulosic textile waste. Remarkably, CO2 interacted with volatile pyrogenic products and transformed them into carbon monoxide (CO). CO2 led to 0.82 times reduction of carbohydrate compounds and 1.18 times increase of CO, in reference to the results from N2. To further enhance the identified reactivity of CO2, the established experimental setup was modified by installing an additional furnace (isothermally heated at 600 °C) and a nickel catalyst (5 wt% Ni/Al2O3). Consequently, CO production from the proposed catalytic pyrolysis increased by 2.01 times. The findings demonstrate that introducing CO2 to the pyrolysis system contributed to the improvement of carbon utilisation efficiency in the form of CO. Therefore, this study offers a framework highlighting technical reliability of carbon dioxide-assisted pyrolysis system for promoting environmental sustainability and resource recovery.

Predicting metabolic pathways and microbial interactions in dark fermentation systems treating real cheese whey effluents

Dark fermentation of agro-industrial effluents is a promising way for waste valorization. However, understanding the complex microbial dynamics and metabolic interactions within the microbial communities remains challenging. This study investigates the microbial communities involved in continuous hydrogen production from cheese whey and fermented cheese whey using functional profiling with PICRUSt2. The analysis reveals the primary roles of key microbial genera. Lactobacillus dominates carbohydrate consumption and lactate production, while Clostridium sensu stricto 12 and Caproiciproducens are engaged in a competitive dynamic for lactate utilization. Clostridium sensu stricto 12 drives hydrogen production via electron bifurcation reactions, whereas Caproiciproducens may utilize alternative energy conservation mechanisms. The interaction between these genera is influenced by substrate availability and process conditions. This study highlights the utility of functional profiling in elucidating microbial interactions and metabolic pathways in dark fermentation. The findings emphasize the importance of understanding microbial interactions to optimize biohydrogen production processes

Plastic waste valorization for formic acid production: A comparison between the electrolysis and hydrogenation process

Plastic waste valorization for formic acid production: A comparison between the electrolysis and hydrogenation process

Valorization of marble sludge waste in biodiesel production using a central composite design.

This work addresses the scarcity of energy resources and environmental issues by concentrating on the synthesis of biodiesel by the transesterification of waste cooking oil with methanol. Marble sludge (MS), a novel heterogeneous catalyst, was used to speed up the rate of reaction. The catalyst's physical and chemical characteristics were thoroughly examined using a variety of methods, including X-ray diffraction, X-ray Fluorescence, SEM, particle size distribution, and BET analysis. Using the MS catalyst, the study investigated the impact of important parameters on the yield of biodiesel from waste cooking oil with the aid of response surface methodology using Design-Expert version 13 software. These parameters included temperature (50-70℃), reaction time (1-4h), catalyst concentration (1-5 wt%), and methanol-to-oil molar ratio (5-20mol/mol). Optimization of the parameters was performed for economic targets to lower the production cost of biodiesel. The results showed that a methanol-to-oil molar ratio of 20:1, a catalyst of 5 wt%, and a reaction time of 1h at 57℃ were the ideal parameters for obtaining a biodiesel yield of 93.5%. The resultant biodiesel revealed promising characteristics, such as a flash point of 160℃, a kinematic viscosity of 4 mm2/s, and a density of 0.871g/cm3. The study demonstrates the significant consequences and real-world advantages of using rational engineering methods to use MS as a very effective, stable, and easily recoverable catalyst for the long-term, sustainable generation of biodiesel from waste cooking oil.

Valorization of Wastes from Wine Industry in the Production of Lightweight Clay Bricks

Lightweight clay brick is an idea that arose from the need to reduce waste by giving grape pomace, a waste product from the Portuguese wine sector, a new use, promoting a circular economy. Compared to ordinary building clay bricks, lightweight clay bricks have higher porosity, and consequently lower density and lower thermal conductivity, while maintaining good mechanical strength, allowing them to be used to build the inner walls in buildings. The production process for this brick, from obtaining the raw materials to manufacturing the brick itself, was studied using process simulation and an economic analysis. The latter led to the conclusion that the project is economically viable and profitable, with each tonne of bricks selling for €57.96.

The Role of Yeast in the Valorisation of Food Waste

The implementation of the circular bioeconomy is now widely accepted as a critical step towards reducing the environmental burden of industrial waste and reducing the impact of this waste on climate change. The valorisation of waste using microorganisms is an attractive and fast-developing strategy capable of achieving meaningful improvements in the sustainability of the biotechnology industry. Yeasts are a powerful chassis for developing valorisation strategies and key opportunities. Thus, this study examines how waste from the food sector can be effectively targeted for valorisation by yeast. Yeasts themselves are critically important elements in the production of food and brewing, and thus, the valorisation of waste from these processes is further reviewed. Policy and regulatory challenges that may impact the feasibility of industrial applications of yeast systems in the valorisation of food waste streams are also discussed.

Circular product development strategies for sustainable production and consumption based on waste valorization

PurposeThis study aims to propose guidelines for developing circular products based on waste recovery that are aligned with sustainable production and consumption.Design/methodology/approachA systematic literature review and case studies on circular product development were conducted. In total, 15 companies with products based on waste recovery and aligned with sustainable production and consumption goal were studied.FindingsThe results show the decisions and strategies applied at each stage of the new product development process, including the design for recycling, the use of waste as a raw material for products and the concern for reducing pollution and recovering end-of-life products.Practical implicationsThe cases studied meet the goals of efficient use of natural resources and waste reduction by preventing, reducing, recycling and reusing waste. For practitioners, a set of guidelines is proposed to help companies develop circular products based on waste recovery.Originality/valuePrevious studies have not evaluated the new product development process and circularity from the institutional theory and waste valorization perspectives.

Supply Chain Design for Waste Valorization Through High-Energy-Density Pellet Production in Chile

This study presents the development and application of a mathematical optimization model to improve decision-making in the supply chain for high-energy-density pellet (HEDP) production and commercialization. Focused on the Metropolitan Region of Chile, the research involved a detailed analysis of key supply chain components, including identifying landfills and controlled dumps, waste volume assessments, plant location analysis, technology evaluation, and market potential exploration. The model revealed that the available raw material in the region was sufficient to meet 100% of HEDP demand, with a surplus of 2,161,952 tons remaining after satisfying maximum demand. An optimization analysis of potential plant locations identified Santa Marta as the optimal choice, resulting in annual cost savings of USD 100,000 compared to other sites. This work underscores the role of mathematical optimization in enhancing supply chain efficiency for biomass-based energy products, offering valuable insights for strategic decision-making in similar contexts.

Briquetting of black soldier fly frass as a post-harvest stabilization strategy

ABSTRACT The production–consumption cycle needs a transition towards a circular economy where waste valorization is included. This study investigated briquetting as a stabilization method for black soldier fly frass (BSFF) with faecal matter, pig manure, and poultry manure as the larvae feed. Herein, dried BSFF was pyrolyzed at 350 °C for 2 h to produce biochar then mixed with charcoal dust in equal ratio to produce biobriquettes through densification, with cassava gel (10 wt%) as binder. One-way ANOVA showed statistical significance in carbon, nitrogen, hydrogen, and oxygen. There were significant differences (p &amp;lt; 0.05) between the calorific value, moisture content, ash content, volatile matter, and fixed carbon of the briquettes. The fixed carbon, volatile matter, moisture, and ash content ranged from 29.66 ± 0.86 to 42.01 ± 0.92, 29.26 ± 0.52 to 32.59 ± 0.80, 2.95 ± 0.1 to 5.08 ± 0.04, and 21.48 ± 0.14 to 37.20 ± 0.29, respectively. The calorific value of the produced briquettes ranged from 16.25 ± 0.57 to 20.70 ± 0.53 MJ/kg, which exceeds the minimum requirement of 14.5 MJ/kg recommended for non-woody briquettes. During combustion, concentrations of NOx, N2O, CO, and CO2 varied significantly across the treatments with the acacia charcoal having the highest concentration of CO. Briquetting is a potential stabilization method for frass resulting in waste reduction, bioenergy production, reduced adverse effects of climate change, and enhanced sustainability.

High-Performance Concrete from Rubber and Shell Waste Materials: Experimental and Computational Analysis

Waste and its environmental impact have driven the search for sustainable solutions across various industries, including construction. This study explores the incorporation of solid waste in the production of eco-friendly structural concrete, aiming to reduce pollution and promote ecological and sustainable construction practices. In this context, two types of eco-friendly concrete were produced using marine shells and recycled rubber as waste materials and compared with conventional concrete through experimental and computational approaches. The results demonstrated that the concrete with marine shells achieved a compressive strength of 32.4 MPa, 26.5% higher than conventional concrete, and a 1% reduction in weight. In contrast, the recycled rubber concrete exhibited a compressive strength of 22.5 MPa, with a 2 MPa decrease compared to conventional concrete, but a 4.3% reduction in density. Computational analysis revealed that porosity affects Young’s modulus, directly resulting in a reduction in the maximum achievable strength. This work demonstrates that it is feasible to produce eco-friendly structural concrete through the proper integration of industrial waste, contributing to decarbonization and waste valorization.

Assessing the Overall Sustainability Performance of the Meat Processing Industry Before and After Wastewater Valorization Interventions: A Comparative Analysis

The meat processing industry is rapidly growing, aiming to enhance the accessibility and affordability of meat products. However, this vital sector also presents significant environmental and social challenges alongside substantial waste management issues. Efforts to improve sustainability in this industry include introducing advanced waste treatment technologies. This study evaluates the overall sustainability of the meat processing industry by comparing the current waste treatment system with an advanced system incorporating improved technologies for water reuse, solid waste valorization, and energy production. We conducted environmental, social, and economic Life Cycle Assessments (LCAs) using OpenLCA and the SOCA v2 database, with 1 kg of processed meat as the functional unit. The comparative analysis highlights significant improvements in the ‘50%’ scenario, where half of the wastewater undergoes advanced treatment. Environmental impacts decreased notably: Freshwater Eutrophication and Human Carcinogenic Toxicity by 25.9% and 31.5%, respectively, and Global Warming and Fossil Resource Scarcity S by 9.2% and 8.8%. Social risk indicators improved by 33.7% to 37.0%. The treatment system achieved a cost saving of EUR 0.00187 per kg of meat (EUR 63,152.70 annually), though these results are specific to this study and heavily dependent on the location and time period. Further analysis of four scenarios, including the baseline, demonstrated that increasing the proportion of wastewater treated by the new system improved environmental, social, and economic outcomes, with the 75% treatment scenario proving the most sustainable. Overall, the advanced treatment system significantly enhances sustainability in the meat industry, promoting a more environmentally, socially, and economically friendly waste management approach.

Humic Substances from Waste-Based Fertilizers for Improved Soil Fertility

This research explores how different organic waste transformation methods influence the production of humic substances (HSs) and their impact on soil quality. Using olive and orange wastes as substrates, the study compares vermicomposting, composting, and anaerobic digestion processes to determine which method produces the most humic-substance-rich products. The characterization of HSs in each product included analyses of total organic carbon (TOC), humic and fulvic acid content, humification rate, humification degree, and E4/E6 ratio, with HSs extracted using potassium hydroxide (KOH) and analyzed via Diffuse Reflectance Infrared Fourier-Transform (DRIFT) spectroscopy to assess structural complexity. The results revealed that the chemical composition of the input materials significantly influenced the transformation dynamics, with orange by-products exhibiting a higher humification rate and degree. Vermicomposting emerged as the most efficient process, producing fertilizers with superior humic content, greater microbial biodiversity, and enhanced cation exchange capacity, thus markedly improving soil quality. Composting also contributed to the stabilization of organic matter, albeit less effectively than vermicomposting. Anaerobic digestion, by contrast, resulted in products with lower levels of HSs and reduced nutrient content. Aerobic processes, particularly vermicomposting, demonstrated the most rapid and effective transformation, producing structurally complex, stable humus-like substances with pronounced benefits for soil health. These findings underscore vermicomposting as the most sustainable and efficacious approach for generating HS-rich organic fertilizers, presenting a powerful alternative to synthetic fertilizers. Furthermore, this study highlights the potential of organic waste valorization to mitigate environmental pollution and foster circular economy practices in sustainable agriculture.

Valorisation of corn waste as fiber, biosilica, and their epoxy composites: fatigue, fracture toughness, water absorption, and drilling properties

Valorisation of corn waste as fiber, biosilica, and their epoxy composites: fatigue, fracture toughness, water absorption, and drilling properties

Design and Technical-Economic-Environmental Evaluation of a Biorefinery Using Non-Marketable Edible Mushroom Waste

Edible mushrooms are gaining popularity as functional foods, not only for their distinctive taste and subtle flavor but also for their potential health benefits. They are rich in essential nutrients, including carbohydrates, proteins, fiber, minerals, and vitamins. However, it is estimated that up to 30% of total mushroom production generates non-marketable waste, which is currently used as animal feed, fertilizer, or compost. From a circular economy perspective, the objective of this work is to propose a conceptual design for a biorefinery to produce high-value-added products from non-marketable edible mushroom waste and to conduct a comprehensive assessment using modeling and simulation tools for process engineering. The general approach first involves identifying high-potential products, then determining the best processing routes, followed by developing a process flowsheet diagram for a case study (A. bisporus), and ultimately conducting a comprehensive assessment of the biorefinery to evaluate its sustainability. As a result, the proposed biorefinery may produce chitin, citric acid, and fertilizer, demonstrating the technical feasibility of waste valorization in terms of product yields, with positive profitability in terms of the rate of return on investment and payback period, and low environmental impact in terms of water and energy consumption as well as CO2 emissions.

Bioactive Compounds, Composition and Potential Applications of Avocado Agro-Industrial Residues: A Review

In recent years, the global production and industrialization of avocados has led to the generation of large numbers of peel, seeds, and leaf by-products with significant environmental implications. Current efforts, including the Sustainable Development Goals, aim towards the development of sustainable operations through the valorization of waste. Previous research has focused on studying the rich chemical composition of these avocado by-products. Current studies are working on the isolation of polyphenols, flavonoids, phenolic acids and other bioactive compounds found in avocado peel, seeds and leaves for applications in nutraceutical products in the food, pharmaceuticals and cosmetics industries. The inclusion of these extracts in industrial matrices often requires stabilization technologies such as encapsulation emulsions to ensure the delivery and bioactivity of these target compounds. This review will discuss the global production volumes of avocado and its by-products as well as the potential inclusion in various industries based on their chemical compositions. Additionally, this work addresses the various applications that have been previously proposed for the wastes and their extracts. This review also covers the stabilization techniques previously employed in avocado extract treatment, their applications, and the current challenges and opportunities associated with avocado by-products.

Sustainable valorization of food waste into a pore-forming agent for ceramic membrane production: Experimental and DFT studies on methylene blue dye removal

Sustainable valorization of food waste into a pore-forming agent for ceramic membrane production: Experimental and DFT studies on methylene blue dye removal

Highly-efficient co-production of microbial lipid and magnesium ammonium phosphate from N-acetyl-D-glucosamine

The valorization of chitin-rich wastes into chemicals and biofuels holds immense economic and environmental benefits. Here, N-acetyl-D-glucosamine (GlcNAc), the basic structural unit of chitin, was firstly described for co-producing microbial lipid and magnesium ammonium phosphate (MAP). Due to the strong substrate inhibition of GlcNAc, a fed-batch culture mode was successfully adopted to achieve high cell density by Cutaneotrichosporon oleaginosum. When a phosphate limitation strategy was applied, cell mass, lipid titer, content, yield, and productivity were 102.7 g/L, 74.2 g/L, 72.2 %, 21.4 g/100 g, and 0.69 g/L/h, respectively. The ammonium ion was efficiently precipitated by forming MAP with a removal rate around 95.4 %. The lipid samples showed high similarity to vegetable oil, which emerged as high-quality precursor for biodiesel production. This study offers a promising strategy for full conversion of GlcNAc into lipid and slow-release fertilizer, which provides an attractive technical route for turning the chitin-rich materials into valuable products.

Novel and sustainable valorization of biogenic waste into microbial protein based fish dietary ingredient in bioreactor: process optimization and sustainable utilization

Novel and sustainable valorization of biogenic waste into microbial protein based fish dietary ingredient in bioreactor: process optimization and sustainable utilization