Search Results (21)

Plastic materials are widely used for packaging due to their versatility and availability. Global production, mainly from petrochemicals, is estimated at 380 million tons, increasing annually by 4%. Packaging plastics have the shortest lifespan and contribute significantly to environmental pollution. Current production, use, and disposal of these plastics harm the environment, hu-mans, and ecosystems. Microplastics, (plastics particles ranging from 1 µm to 5 mm) formed through degradation, accumulate in ecosystems and the human body, including the brain. Bioplastics and biodegradable polymers from biological sources are a sustainable alternative; however, most production still relies on food crops, raising concerns about food security and sustainability. Utilizing organic wastes reduces production costs, lessens pressure on food systems, and supports waste management efforts. Cellulose, an abundant natural polymer, offers strong potential due to biodegradability, availability, and mechanical properties. This review explores extracting cellulose from banana pseudostem waste for packaging, high-lighting extraction and conversion methods and characterization via FTIR, TGA, SEM, XRD, and mechanical testing. FTIR confirmed the effective removal of lignin and hemicellulose, XRD revealed increased crystallinity corresponding to Type I cellulose, SEM showed a roughened fiber surface after alkaline treatment, and TGA indicated high thermal stability up to 250 °C. The goal is eco-friendly packaging by promoting agrowaste use. Further research should improve performance and scalability of cellulose-based bioplastics to meet industry needs and compete effectively with conventional plastics. Full article

In the food packaging industry, significant efforts have been dedicated to addressing the pressing market demand for environmentally friendly and sustainable products. Biocomposite films based on compostable and biobased polymers represent a sustainable alternative to conventional packaging materials, offering biodegradability and enhanced functional properties. Additionally, there is growing interest in utilizing waste materials from agriculture and the food industry. This study focuses on the development of multifunctional eco-sustainable biocomposite films by combining poly(lactic acid) (PLA) as a biopolymeric matrix and extracts derived from coffee silverskin (CS), a significant agro-industrial waste byproduct of the coffee roasting process. Extracts of coffee silverskin were obtained via extraction with several solvents. Several properties of the prepared biocomposites were measured using techniques such as scanning electron microscopy (SEM), infrared spectroscopy (FTIR, ATR), differential scanning calorimetry (DSC), and oxygen and water vapor permeability, together with mechanical and physico-chemical characterization and measurements of water content, film solubility, and degree of swelling. The results demonstrate that optimized formulations of PLA/CS biocomposite films exhibit enhanced oxygen barrier properties, reduced permeability, and significant antioxidant activity. These findings underscore the potential for agro-waste valorization in creating eco-friendly food packaging solutions. Full article

Agricultural waste derivatives, particularly tomato cutin, a biopolymer found in the cuticular layer of plants, present a promising alternative for the development of sustainable materials in biomedical applications. Cutin, composed primarily of fatty acids and hydroxy acids, exhibits favorable biodegradability, biocompatibility, and hydrophobic properties, positioning it as a viable candidate for applications such as drug delivery systems, wound healing, and tissue engineering. This study investigates the extraction, characterization, and potential biomedical utilization of 10,16-dihydroxy hexadecenoic acid monomer derived from tomato cutin agro-waste. The cytotoxicity of cutin-based materials was evaluated through in vitro assays, demonstrating minimal toxicity and confirming their suitability for biomedical applications. The extraction process was optimized using various solvents, and the molecular characteristics of the extracted monomer were assessed using techniques such as Gel Permeation Chromatography (GPC), Gas Chromatography–Mass Spectroscopy (GC-MS) ¹H and ¹³C Nuclear Magnetic Resonance (NMR), Fourier Transformed Infrared (FT-IR) spectroscopy, Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC). MTT assay was also performed on NHDFs cultured in monomer solutions to assess their cytocompatibility. The findings suggest that cutin-based materials, when processed under environmentally sustainable conditions, offer an effective and biocompatible alternative to conventional synthetic polymers, opening new avenues for the development of sustainable biomedical products. Full article

A tremendous amount of waste black tea bags (BTBs) and date palm surface fibers (DPSFs), at the end of their life cycle, end up in landfills, leading to increased pollution and an increase in the negative impact on the environment. Therefore, this study aims to utilize these normally wasted materials efficiently by developing new composite materials for thermal insulation and sound absorption. Five insulation composite boards were developed, two were bound (BTB or DPSF with polyvinyl Acetate resin (PVA)) and three were hybrids (BTB, DPSF, and resin). In addition, the loose raw waste materials (BTB and DPSF) were tested separately with no binder. Thermal conductivity and sound absorption coefficients were determined for all boards. Thermal stability analysis was reported for the components of the tea bag (string, label, and bag) and one of the composite hybrid boards. Mechanical properties of the boards such as flexural strain, flexural stress, and flexural elastic modulus were determined for the bound and hybrid composites. The results showed that the thermal conductivity coefficients for all the hybrid composite sample boards are less than 0.07 at the ambient temperature of 24 °C and they were enhanced as the BTB ratio was reduced in the hybrid composite boards. The noise reduction coefficient for bound and all hybrid composite samples is greater than 0.37. The composite samples are thermally stable up to 291 °C. Most composite samples have a high flexure modulus between 4.3 MPa and 10.5 MPa. The tea bag raw materials and the composite samples have a low moisture content below 2.25%. These output results seem promising and encouraging using such developed sample boards as eco-friendly thermal insulation and sound absorption and competing with the synthetic ones developed from petrochemicals in building insulation. Moreover, returning these waste materials to circulation and producing new eco-friendly composites can reduce the number of landfills, the level of environmental pollution, and the use of synthetic materials made from fossil resources. Full article

Straw, the primary agricultural waste, constitutes approximately 20% of the total biomass in the EU. Only a small fraction of the material is applied in various products, e.g., animal bedding, mulch, building, and composite materials, while a significantly larger portion is often burned in the field. This practice, while prohibited for several reasons, including the increased risk of fire and the release of carbon dioxide contributing to global warming, is still prevalent. Given the increasingly evident effects of climate change, EU legislation aims to reduce greenhouse gas emissions as much as possible. One of the strategies includes applying the cascade principle in the circular economy. This principle aims to use the entire raw material, in this case, cereal crops, such that the products with the highest added value, like cellulose fibers from cereal straw, are extracted first. The vast potential for utilizing lignocellulosic agro-waste sustainably arises from its status as the most abundant organic compound on Earth. Its significant presence, renewability, and biodegradability make it a desirable source for producing materials in numerous industries. This study examines the potential of wheat fibers, isolated from the straw of two distinct cultivars (Srpanjka represents an old variety, and Kraljica represents the new variety) primarily for application in technical textiles. The following testing methods were applied: determination of wheat fibers and residues yield, fibers tensile properties, length, moisture content/regain, density, morphology, and Fourier transform infrared (FTIR) spectroscopy. The yield of isolated fibers relies on the wheat variety and the climatic conditions affecting plant growth, resulting in fiber yields from 10.91% to 15.34%. Fourier transform infrared (FTIR) analysis indicates reduced peak intensity, which is related to hemicellulose and lignin content, suggesting their improved deposition following the process of chemical maceration. Wheat fiber quality was found to be comparable to cotton fibers regarding its density. However, they showed a significant difference in higher moisture regain (9.72–11.40%). The vast majority of the scientific papers related to wheat fibers did not indicate the length of the individual fibers obtained by chemical maceration nor their strength. Therefore, this paper indicated that both varieties demonstrated sufficient fiber tenacity (greater than 10 cN/tex) and fiber length (2–3 cm), stressing the spinning potential of these fibers into yarns and extending their use to the apparel industry. Moreover, our research underscores the feasibility of adhering to the zero-waste principle. A high percentage of solid waste remaining after fiber extraction (25.3–39.5%) was successfully used for biofuel production, thus closing the loop in the circular economy. Full article

On a global scale, millions of tons of diverse agricultural residues are generated annually. Most of these wastes are burned or dumped in landfills, which causes environmental pollution. Addressing environmental issues arising from agricultural waste materials, in addition to mitigating heating and cooling expenses in the construction sector, is an interesting challenge for researchers. The utilization of agricultural wastes in different parts of construction is producing positive findings day by day, and investigating research in this field is a curiosity for researchers. This short study reviewed the most recent achievements in using agricultural wastes as a substitute or additive material for construction. Using these wastes as aggregate, ash (as a supplementary for cement), or fibers for foam concrete, insulation materials, etc. has been reviewed. This review has focused on very recent published papers. Several studies have demonstrated the effective influences of agro-waste materials in construction, like retaining the compressive strength (155 MPa) of concrete at standard levels and reducing heat losses in buildings (69% energy savings for brick insulated using wheat straw), as well as sound insulation. The use of agro-waste materials for insulation positively improved thermal conductivity, costs, and energy savings. However, some wastes did not provide a high added value, which shows that more investigations still need be performed to fill this gap in the research. Considering the global scale of agricultural waste generation and the potential benefits to both the environment and construction industry, continued research in this area is essential. Full article

Pineapple leaf fiber (PALF), striped sunflower seed fiber (SFSF), and watermelon seed (WMS) are considered natural waste polymer materials, which are biodegradable and sustainable. This study presents new novel thermal insulation and sound absorption materials using such waste as raw materials. PALF, SFSF, and WMS were used as loose, bound, and hybrid samples with different compositions to develop promising thermal insulation and sound-absorbing materials. Eleven sample boards were prepared: three were loose, three were bound, and five were hybrid between PALF with either SFSF or WMS. Wood adhesive was used as a binder for both the bound and hybrid sample boards. Laboratory scale sample boards of size 30 cm × 30 cm with variable thicknesses were prepared. The results show that the average thermal conductivity coefficient for the loose samples at the temperature range 20–80 °C is 0.04694 W/(m.K), 0.05611 W/(m.K), and 0.05976 W/m.K for PALF, SFSF, and WMS, respectively. Those for bound sample boards are 0.06344 W/(m.K), 0.07113 W/(m.K), and 0.08344 W/m.K for PALF, SFSF, and WMS, respectively. The hybrid ones between PALF and SFSF have 0.05921 W/m.K and 0.06845 W/(m.K) for two different compositions. The other hybrid between PALF and WMS has 0.06577 W/(m.K) and 0.07007 for two different compassions. The sound absorption coefficient for most of the bound and hybrid boards is above 0.5 and reaches higher values at some different frequencies. The thermogravimetric analysis for both SFSF and WMS shows that they are thermally stable up to 261 °C and 270 °C, respectively. The three-point bending moment test was also performed to test the mechanical properties of the bound and hybrid sample boards. It should be mentioned that using such waste materials as new sources of thermal insulation and sound absorption materials in buildings and other applications would lead the world to utilize the waste until zero agrowaste is reached, which will lower the environmental impact. Full article

The industrial harvesting of sea buckthorn (SBT) berries with twigs and subsequent pruning creates a large volume of lignocellulosic agro-waste. This study aimed to valorize this agro-waste as a raw material for animal feed and fuel granules, for developing a sustainable cascading SBT production scheme. Five SBT cultivars’ biomasses were characterized by analytical pyrolysis, mass spectrometry, and GC analysis. Condensed tannins, which are undesirable components for animal feed, were separated by extraction. The residue was analyzed for total protein, vitamins (A, C, and E), ash, crude fat, wood fiber, and macroelements (P, K, Ca, and Na), and showed great potential. The heavy metal (Cd, Hg, and Pb) content did not exceed the permitted EU maximum. Granulation regimes were elaborated using a flat-die pelletizer, KAHL 14-175. The digestibility and the amount of produced gas emissions were determined using in vitro systems that recreate the digestion of small ruminants. The investigation proved that SBT leaves and stems are a unique underutilized source of animal feed, used alone or in combination with others. Twigs, due to their thorns, were granulated and valorized according to standards for application as fuel. The scheme offered in this study enables SBT agro-waste utilization and sustainable SBT berry production. Full article

The exponential growth of agricultural output is a result of the increasing world population. Agro-wastes are now acknowledged as an alternative material for the manufacture of renewable, inexpensive, and sustainable bio-composite-based products. Huge amounts of agricultural produce are often lost owing to a lack of processing facilities or storage space. Agriculture wastes contain a significant concentration of carbohydrates as well as various multifunctional groups and organic substances, such as polymeric proteins. Interestingly, nanotechnology provides better potential to transform agricultural wastes easily into valuable and cost-effective products, removing the need to utilize noxious chemicals, which can create a variety of health and environmental difficulties. Recently, there has been an increase in interest in eco-friendly nanomaterial (NM) production techniques that utilize extracts generated from agricultural waste. Such nanoparticles (NPs) have been extensively studied for numerous uses, including antibacterial agents, water purification, the breakdown of industrial colours, and many others. Consequently, the purpose of this review is to investigate the different sources, characteristics, and nano-management of agro-waste; valuable NMs derived from agro-waste; and their possible applications. Full article

Waste management in the agricultural sector has become a major concern. Increased food production to satisfy the surge in population has resulted in the generation of large volumes of solid waste. Agro-waste is a rich source of biocompounds with high potential as a raw material for food packaging. Utilization of agro-waste supports the goal of sustainable development in a circular economy. This paper reviews recent trends and the development of agro-wastes from plant and animal sources into eco-friendly food packaging systems. Different plant and animal sources and their potential development into packaging are discussed, including crop residues, process residues, vegetable and fruit wastes, and animal-derived wastes. A comprehensive analysis of the properties and production methods of these packages is presented. Future aspects of agro-waste packaging systems and the inherent production problems are addressed. Full article

Geopolymers have been mainly utilized as structural materials; their chemical structure and morphologies have been explored for their potential as a high-performance material in emerging applications. Geopolymer composites reinforced with materials based on agro-waste are attracting interest in engineering applications due to their easy processing, low cost, low density, and high strength-to-weight ratio. This investigation pursues an experimental methodology that consists of a scheme to make composites with a geopolymer matrix and agro-waste (rice husk, barley, and coffee) as aggregate material, that can be applied in various fields of construction. The study was intended to determine the influence of adding various agro-wastes on the mechanical properties of the geopolymer. According to the respective ASTM standards, the materials obtained were prepared and analyzed to determine their compressive strength, flexural strength, hardness and scanning electron microscopy (SEM)-determined characteristics. The results revealed that, for the compression tests, the composites formed by a sol-gel matrix and barley husk showed a better yield, obtaining the highest value of 3.5 N/mm². Concerning hardness testing, the composites with a geopolymer matrix and coffee husks obtained higher values compared to the other composites. For the flexural tests, the compounds with the sol-gel/fly ash matrix obtained the highest yield stress value, which was 5.25 MPa with an elastic modulus of 7.59 GPa. The results of the microstructural analysis showed good husk-matrix interaction, together with failure mechanisms. The conformation of such waste-based compounds may enable them to replace natural wood in some applications, such as in the finishing of interiors of homes, during the final stages in the construction of buildings, or in the decoration of inhabited houses, as well as in finishing in the manufacture of furniture. Full article

This current study reviews the utilization of the traditional extraction methods and latest findings in extraction of silica from agricultural wastes, in particular, sugarcane bagasse, using inorganic acids to produce nano-silicon. The three key processes discussed in detail include electrochemical, ball milling, and sol–gel processes. The sugarcane bagasse has been identified as the cheapest source of producing silica from the potential raw material for the preparation of nano-silicon. The acid-base extraction and precipitation methodology involves the use of bases like sodium hydroxide (NaOH) and potassium hydroxide (KOH), and acids such as hydrofluoric acid (HF), sulphuric acid (H₂SO₄), nitric acid (HNO₃), and hydrochloric acid (HCl) for the treatment of the ash. Sugarcane bagasse has notably emerged as an excellent and sustainable source of both tailored silica particles and bioenergy production. The ability to manipulate the engineered silica particles at the nano-level from sugarcane bagasse-based silica is explained in detail. Silica is a significant raw material with various industrial applications, with much research underway to extract it efficiently from industrial agro-waste, such as sugarcane bagasse. The production of highly pure silicon nanoparticles from sugarcane bagasse ash will serve as an important synthetic route in lowering the manufacturing costs and providing a low-cost polycrystalline silicon semiconductor for niche application in thin film solar technology. Full article

Adsorption of the carcinogen aflatoxin B₁ (AFB₁) onto agro-waste-based materials is a promising alternative over conventional inorganic binders. In the current study, two unmodified adsorbents were eco-friendly prepared from kale and lettuce agro-wastes. A dynamic gastrointestinal tract-simulated model was utilized to evaluate the removal efficiency of the sorptive materials (0.5%, w/w) when added to an AFB₁-contaminated diet (100 µg AFB₁/kg). Different characterization methodologies were employed to understand the interaction mechanisms between the AFB₁ molecule and the biosorbents. Based on adsorption results, the biosorbent prepared from kale was the best; its maximum adsorption capacity was 93.6%, which was significantly higher than that of the lettuce biosorbent (83.7%). Characterization results indicate that different mechanisms may act simultaneously during adsorption. Non-electrostatic (hydrophobic interactions, dipole-dipole interactions, and hydrogen bonding) and electrostatic interactions (ionic attractions) together with the formation of AFB₁-chlorophyll complexes appear to be the major influencing factors driving AFB₁ biosorption. Full article

The common applications of poly(vinyl chloride) (PVC) in many industries mean that the topic of recycling and disposal of post-consumer waste is still very important. One of the methods of reducing the negative impact of PVC waste on the natural environment is to use technological or post-consumer waste of this polymer to produce new composite materials with favorable utility properties, with the addition of natural fillers, among which agro-waste, including hop residue, is deserving of special attention. In this study, the effect of the addition of residual hops (H) on the mechanical and physicochemical properties of poly(vinyl chloride) was investigated. PVC blends containing 10, 20 and 30 wt % of hop residue were mixed in an extruder, while the specimens were obtained by the injection molding method. It was observed that the addition of H increased their thermostability, as shown by a Congo red test. Furthermore, thermogravimetric analysis showed that the degradation rate of PVC/H composites in the first and second stages of decomposition was lower in comparison with unmodified PVC. In turn, composite density, impact strength and tensile strength decreased significantly with an increasing concentration of filler in the PVC matrix. At the same time, their Young’s modulus, flexural modulus and Rockwell hardness increased. Flame resistance tests showed that with an increasing residual hop content, the limiting oxygen index (LOI) decreased by 9.0; 11.8 and 13.6%, respectively, compared to unfilled PVC (LOI = 37.4%). In addition, the maximum heat release rate (pHRR) decreased with an increasing filler content by about 16, 24 and 31%, respectively. Overall, these composites were characterized by a good burning resistance and had a flammability rating of V0 according to the UL94 test. Full article

Several agro-waste materials have been utilized for sustainable engineering and environmental application over the past decades, showing different degrees of effectiveness. However, information concerning the wider use of palm oil clinker (POC) and its performance is still lacking. Therefore, as a solid waste byproduct produced in one of the oil palm processing stages, generating a huge quantity of waste mostly dumped into the landfill, the waste-to-resource potential of POC should be thoroughly discussed in a review. Thus, this paper provides a systematic review of the current research articles on the several advances made from 2005 to 2021 regarding palm oil clinker physical properties and performances, with a particular emphasis on their commitments to cost savings during environmental and engineering applications. The review begins by identifying the potential of POC application in conventional and geopolymer structural elements such as beams, slabs, and columns made of concrete, mortar, or paste for coarse aggregates, sand, and cement replacement. Aspects such as performance of POC in wastewater treatment processes, fine aggregate and cement replacement in asphaltic and bituminous mixtures during highway construction, a bio-filler in coatings for steel manufacturing processes, and a catalyst during energy generation are also discussed. This review further describes the effectiveness of POC in soil stabilization and the effect of POC pretreatment for performance enhancement. The present review can inspire researchers to find research gaps that will aid the sustainable use of agroindustry wastes. The fundamental knowledge contained in this review can also serve as a wake-up call for researchers that will motivate them to explore the high potential of utilizing POC for greater environmental benefits associated with less cost when compared with conventional materials. Full article