Thermochemical processing of biowaste generates renewable carbon-rich materials with potential agronomic uses, contributing to waste valorization. This study evaluates the application of hydrochar obtained from hydrothermal carbonization of food waste, those obtained by different post-treatments (washing, aging, and thermal treatment), as well as biochar obtained by pyrolysis as soil amendments. For this purpose, the effect of char addition (1-10 wt% d.b.) on a marginal agricultural soil on germination and growth of Solanum lycopersicum (tomato) plants was assessed. All the hydrochars exhibited a chemical composition suitable for agronomic use, characterized by high nutrient content, abundant organic matter, and low concentration of phytotoxic metals. In contrast, biochar exceeded the permissible limits for Cr, Cu, and Ni concentrations rendering it unsuitable for application to agronomic crops. The high temperature of thermal post-treatment and pyrolysis favored mineral and heavy metal concentration while washing significantly reduced nutrient content (N, S, P, K, Mg) along with the electrical conductivity. The addition of biochar or both washed and thermally post-treated hydrochar negatively affected tomato growth. Reduced chlorophyll content was associated with the decreased expression of genes encoding enzymes involved in antioxidant metabolism. This led to photosynthetic membrane damage, as evidenced by chlorophyll fluorescence-related parameters. Conversely, the addition of aged (<= 5 wt %) and fresh (1-10 wt%) hydrochars increased both germination and plant growth compared to unamended soil, indicating that hydrochar from food waste does not require additional post-treatments to be used as a soil amendment.

Transforming waste materials into valuable commodities is a promising strategy to alleviate challenges associated with managing solid waste, benefiting both the environment and human well-being. This study is focused towards harnessing the potential of waste eggshell microparticles (ESMP) (0.10, 0.15, 0.20 g/150 mL) as reinforcing biofiller and orange peel essential oil (OPEO) (14 %, 25 % and 36 %, w/w) as bioactive agent with pectin (2.80, 2.85, 2.90, and 3.00 g/150 mL) to fabricate five different biocomposite films using particle dispersion and solvent casting technique. The addition of ESMP and OPEO progressively increased film thickness and led to variations in transparency. Micromorphological analysis and vibrational spectroscopy indicated hydrophobicity and compactness, as showed by the loss of free O- H bonds, sharpening of aliphatic C- H and stretching of C = C, C- O and C- O- C bonds with increasing filler content. Noticeable improvements in thermal stability and tensile strength were observed, while the flexibility was minimized. The films displayed remarkable barrier properties against hydrological stress, as evidenced by a reduction in water activity, moisture content, water uptake capacity, and solubility. The antioxidant activity against DPPH radicals suggested efficient release of bioactive compounds. Antibacterial assessment revealed inhibitory effect on Staphylococcus aureus and Bacillus cereus. During soil burial, notable weight loss along with shrinkage confirmed the film biodegradability. In conclusion, the pectin-ESMP-OPEO biocomposite films show potential characteristics as food packaging materials, warranting further performance testing on food samples.

Waste from the fishing industry is disposed of in soils and oceans, causing environmental damage. However, it is also a source of valuable compounds such as chitin. Although chitin is the second most abundant polymer in nature, its use in industry is limited due to the lack of standardized and scalable extraction methods and its poor solubility. The deacetylation process increases its potential applications by enabling the recovery of chitosan, which is soluble in dilute acidic solutions. Chitosan is a polymer of great importance due to its biocompatible and bioactive properties, which include antimicrobial and antioxidant capabilities. Chitin extraction and its deacetylation to obtain chitosan are typically performed using chemical processes that involve large amounts of strongly acidic and alkaline solutions. To reduce the environmental impact of this process, extraction methods based on biotechnological tools, such as fermentation and chitin deacetylase, as well as emerging technologies, have been proposed. These extraction methods have demonstrated the potential to reduce or even avoid using strong solvents and shorten extraction time, thereby reducing costs. Nevertheless, it is important to address existing gaps in this area, such as the requirements for large-scale implementation and the determination of the stoichiometric ratios for each process. This review highlights the use of biotechnological tools and emerging technologies for chitin extraction and chitosan production. These approaches truly minimize environmental impact, reduce the use of strong solvents, and shorten extraction time. They are a reliable alternative to fishery waste valorization, lowering costs; however, addressing the critical gaps for their large-scale implementation remains challenging.

Pulp and paper mill sludge is composed of cellulosic waste and clay and is rich in microorganisms that can benefit horticulture. However, its application in horticulture has received less research attention. Field and greenhouse studies were carried out to determine if sludge from a case study industry can replace the typical cellulosic additive utilized in hydroseeding, and the ideal application rate of a sludge-soil-seed mixture. The treatments were 0-100% sludge and soil by mass with a consistent mass of embedded seeds of Kentucky Bluegrass (Poa pratensis), Creeping Red Fescue (Festuca rubra), Perennial (Lolium perenne) and Annual Ryegrass (Lolium multiflorum). Seeding with a top layer of soil and 5 to 75% sludge gave the best outcome using a cellulosic additive after 3 weeks of growth. Mixtures containing 5-25% sludge resulted in the quickest seed germination rate. The cellulosic additive has the capacity to retain a higher volume of water but requires 15 times more material by volume. An increase in sludge increased water retention by 20%. Overall, the cellulosic additive in hydroseeding applications can be replaced by sludge without plant detriment. However, further testing is needed to determine long-term effects. [GRAPHICS] .

There is an increasing demand for sustainable construction materials to address the challenges posed by the environmental impact of the built environment (BE), which is driven by climate change, population growth, and urbanization. Conventional construction materials like cement contribute significantly to carbon emissions during production, transport, use, and disposal phases, and their poor thermal conductivity hinders efforts to maintain comfortable indoor environments. To address these challenges, there is an urgent need for innovative, locally sourced thermal insulation materials specifically designed for regions with extreme climates and high energy demands to maintain building comfort. This research explores synthesizing novel, environmentally friendly building materials using locally sourced date palm fiber waste and clay. The study also investigates the developed material's 3D printing (3DP) capabilities and optimizes its printing parameters with lab-scale prototypes. Additionally, thermo-mechanical characterization is conducted to assess its suitability for built environment applications. Different concentrations, from 1 to 5 wt% of date palm fiber to clay ratio (Dpf/C), were studied regarding microstructural, thermal, and mechanical properties, dimensional accuracy, and feasibility for 3DP of BE structures. Results demonstrated a significant reduction in thermal conductivity by 73%, achieving 0.244 W/mK, and an increase in compressive strength by 106%, reaching 10.9 MPa at 5 wt% Dpf/C. The promising thermomechanical properties of these composites and their suitability for 3DP support their use in real-world applications in the future's sustainable built environment. This scalable methodology can be adapted to regions with similar sustainable local and waste resources, advancing the circular economy.

To prevent the transmission of airborne infectious diseases (SARS, H1N1, COVID-19, and influenza), the use of disposable surgical face masks has increased dramatically in the past few years. To mitigate the environmental consequences associated with mask waste, implementing circular economy strategies with the reuse of mask waste is a sustainable method. This study explores an innovative way to reuse mask fiber (MF) with dredged sediment waste together as road construction materials. First, the MF was introduced into cement-treated/ untreated dredged marine sediment mixtures with different content and lengths. Then, a variety of laboratory tests were carried out to explore the basic physical and chemical characterization of raw materials and the development of mechanical properties of mixtures. In addition, the intrinsic mechanism of MF inclusion on cement-treated sediments was analyzed by scanning electron microscope (SEM) test. The results show that the inclusion of MF significantly improves the unconfined compression strength (UCS) and splitting tensile strength (STS) of both treated and untreated specimens. The highest UCS and STS values are at the condition with an MF content of 0.25%, a length of MF of 2 cm, and a curing time of 28 days. The combined strength increase caused by cement-MF together inclusion is much greater than the strength increase caused by either of them separately. It was also found that the elastic modulus (E50) decreased with the inclusion of MF. Furthermore, the addition of MF changes the brittle behavior of the specimens, which also improves the ductility and residual strength of the specimens. The SEM analysis demonstrates the microstructure of MF and MF-reinforced specimens. The creation of a stable and interconnected microstructure is largely attributed to the bridging impact of MF and the binding effect of hydration products, which significantly improves the mechanical behavior of specimens. The MFreinforced cement-treated sediment could be an innovative, environmentally friendly, and economical material for road construction.

Agricultural residues are generated during the production and processing of agricultural crops. Under modern date palm plantation practices, field operations generate huge quantities of residues, which are discarded with little valorization. The date palm agro-industry produces significant amounts of waste. The accumulation of these residues can cause ecological damage to the oasis ecosystems. There is a lack of comprehensive data on long-term research studies that aim to assess the impact of date palm waste management practices. Composting and/or pyrolysis of date palm residues showed benefits for improving soil physical and chemical properties, particularly in sandy soils. This claim holds particular significance for arid and semi-arid regions, which are characterized by low fertility and are susceptible to soil degradation, accentuated by ongoing climate change. This review summarizes the existing literature concerning the valorization of date palm residues with regards to compost and pyrolysis processes, as well as the impact of their application on soil quality. Further research is required to assess the effects of using date palm residues for better soil amendment management. Research should focus on composting and biochar technologies for date palm residues and their application in arid and semi-arid regions to combat soil erosion and degradation. Increasing the beneficial uses of date palm residues could lead to sustainable and economic growth in dry areas.

Plastic pots used in horticultural nurseries generate substantial waste, causing environmental pollution. This study aimed to develop biodegradable composites from banana pseudo-stem reinforced with agricultural residues like pineapple leaves, taro and water hyacinth as eco-friendly substitutes. The aim of this study is to develop optimised banana biocomposite formulations with suitable reinforcements that balance mechanical durability, biodegradation, and seedling growth promotion properties to serve as viable eco-friendly alternatives to plastic seedling pots. This study was carried out by fabricating banana fibre mats through pulping, drying and hot pressing. Composite sheets were reinforced with 50 % pineapple, taro or water hyacinth fibres. The mechanical properties (tensile, yield strength, elongation, bursting strength), hydrophilicity (contact angle, water absorption), biodegradability (soil burial test), and seedling growth promotion were evaluated through appropriate testing methods. The results show that banana-taro composites exhibited suitable tensile strength (25 MPa), elongation (27 %), water uptake (41 %) and 82 % biodegradation in 60 days. It was observed that biodegradable seedling trays fabricated from banana-taro composite showed 95 % tomato seed germination and a 125 cm plant height increase in 30 days, superior to plastic trays. The finding shows that the study demonstrates the potential of banana-taro biocomposites as alternatives to plastic nursery pots, enabling healthy seedling growth while eliminating plastic waste pollution through biodegradation.

The environmental invasion of plastic waste leads to, among other things, a reassessment of natural fibers. Environmental pollution has shown the importance of the degradability, among other properties, of the raw materials used by the textile industry or other industrial fields. Wool seems to be a better raw material than the polymers that generate large quantities of micro- and nano-plastics, polluting the soil, water, and air. However, the usual processing of raw wool involves a number of chemically very polluting treatments. Thus, sustainable procedures for making wool processing environmentally friendly have been considered, leading to the reappraisal of wool as a suitable raw material. Besides their applications for textile products (including smart textiles), new directions for the valorization of this natural material have been developed. According to the recent literature, wool may be successfully used as a thermal and phonic insulator, fertilizer, or component for industrial devices, or in medical applications, etc. In addition, the wool protein alpha-keratin may be extracted and used for new biomaterials with many practical applications in various fields. This review makes a survey of the recent data in the literature concerning wool production, processing, and applications, emphasizing the environmental aspects and pointing to solutions generating sustainable development.

The development of sustainable materials from the valorization of waste is a good alternative to reducing the negative environmental impact of plastic packaging. The objectives of this study were to develop and characterize pectin-based composite films incorporated with cork or cork with either coffee grounds or walnut shells, as well as to test the films' genotoxicity, antioxidant properties, and biodegradation capacity in soil and seawater. The addition of cork, coffee grounds, or walnut shells modified the films' characteristics. The results showed that those films were thicker (0.487 +/- 0.014 mm to 0.572 +/- 0.014 mm), more opaque (around 100%), darker (L* = 25.30 +/- 0.78 to 33.93 +/- 0.84), and had a higher total phenolic content (3.17 +/- 0.01 mg GA/g to 4.24 +/- 0.02 mg GA/g). On the other hand, the films incorporated only with cork showed higher values of elongation at break (32.24 +/- 1.88% to 36.30 +/- 3.25%) but lower tensile strength (0.91 +/- 0.19 MPa to 1.09 +/- 0.08 MPa). All the films presented more heterogeneous and rougher microstructures than the pectin film. This study also revealed that the developed films do not contain DNA-reactive substances and that they are biodegradable in soil and seawater. These positive properties could subsequently make the developed films an interesting eco-friendly food packaging solution that contributes to the valorization of organic waste and by-products, thus promoting the circular economy and reducing the environmental impact of plastic materials.