Search Results (13)

This paper investigates the cultural, spiritual, and ecological use and value of fish by-products in the material practices of Alaska Native (Indigenous Peoples are the descendants of the populations who inhabited a geographical region at the time of colonisation and who retain some or all of their own social, economic, cultural, and political institutions. In this paper, I use the terms “Indigenous” and “Native” interchangeably. In some countries, one of these terms may be favoured over the other.) and Greenlandic Inuit women. It aims to uncover how fish remnants—skins, bones, bladders, vertebrae, and otoliths—were transformed through tanning, dyeing, and sewing into garments, containers, tools, oils, glues, and adornments, reflecting sustainable systems of knowledge production rooted in Arctic Indigenous lifeways. Drawing on interdisciplinary methods combining Indigenist research, ethnographic records, and sustainability studies, the research contextualises these practices within broader environmental, spiritual, and social frameworks. The findings demonstrate that fish-based technologies were not merely utilitarian but also carried symbolic meanings, linking wearers to ancestral spirits, animal kin, and the marine environment. These traditions persisted even after European contact and the introduction of glass trade beads, reflecting continuity and cultural adaptability. The paper contributes to academic discourse on Indigenous innovation and environmental humanities by offering a culturally grounded model of zero-waste practice and reciprocal ecology. It argues that such ancestral technologies are directly relevant to contemporary sustainability debates in fashion and material design. By documenting these underexamined histories, the study provides valuable insight into Indigenous resilience and offers a critical framework for integrating Indigenous knowledge systems into current sustainability practices. Full article

Although oily sludge is an industrial waste and difficult to separate, its calorific value can still reach 6000 cal/g, thus possessing significant recycling value. This study compares various types of non-thermal plasma for refining oily sludge. The pre-treatment technology utilized filtration combined with solvent extraction to extract the oil portion from the oily sludge. Subsequently, two types of non-thermal plasma, DC streamer discharge and dielectric plasma discharge, were used to crack and activate the oily sludge under different operating conditions. The fuel compositions and properties of the refined fuel treated by two types of non-thermal plasma were compared. The elemental carbon and oxygen of the oily sludge after treatment in a direct DBD plasma reactor for 8 min were 1.96 wt.% less and 1.38 wt.% higher than those of commercial diesel. The research results indicate that the pre-treatment process can effectively improve the refined fuel properties. After pre-treatment, the calorific value of the primary product from the oily sludge can reach 10,598 cal/g. However, the carbon residue of the oily sludge after pre-treatment remained as high as 5.58 wt.%, which implied that further refining processes are required. The streamer discharge plasma reactor used a tungsten needle tip as a high-voltage electrode, leading to a rather small treated range. Corona discharge and arc formation are prone to being produced during the plasma action. Moreover, the addition of quartz glass beads can form a protruding area on the surface of the oily sludge, generating an increase in the reacting surface of the oily sludge, and hence an enhancement of treatment efficiency, in turn. The direct treatment of DBD plasma can thus have a wider and more uniform operating range of plasma generation and a superior efficiency of plasma reaction. Therefore, a direct DBD type of non-thermal equilibrium plasma reactor is preferable to treat oily sludge among those three types of plasma reactor designs. Additionally, when the plasma voltage is increased, it effectively enhances fuel properties. Full article

This study investigates the potential of additive-free extraction techniques to produce a proteolytically active yeast extract for use in the food industry. Brewer’s spent yeast, a by-product of the brewing industry, is utilized as a feedstock, and thus a new route for its valorization is proposed. Four methods of releasing these components while maintaining their intrinsic bioactivity are investigated: thermal autolysis, ultrasonication, cell milling and high-pressure homogenization. Thermal yeast autolysis resulted in the highest release of protease activity, with 2.45 ± 0.05 U/g_dm after 3 h incubation at 45 °C. However, autolysis poses challenges for automation, and thus a stop criterion, due to the lack of in-line enzyme activity assays,. While glass bead treatment gave the highest reproducibility, ultrasonication and high-pressure homogenization resulted in comparably high protease activities in the BSY extracts produced. Both methods, in the form of a cell mill and high-pressure homogenizer, are cell disruption methods that are already employed on an industrial scale. It has now been demonstrated that these methods can be used to produce proteolytically active yeast extracts from a previously considered waste stream. Full article

Glass was introduced as an additive to filaments used for the manufacturing of composite materials, employed by Additive Manufacturing applications. Glass accounts for a large waste electric and electronic equipment (WEEE) percentage, and its recovery and recycling can lead to the production of sustainable composite materials. In this work, poly(lactic acid) (PLA)/commercially available silicon oxide composite filaments were manufactured and their structural, thermal, rheological, and mechanical properties were assessed. Scanning Electron Microscopy confirmed the 1:2 ratio of silicon: oxygen, along with the relatively low adhesion between the filler and the matrix. Differential Scanning Calorimetry presented steady glass transition and melting temperatures of composites, whereas a crystallization temperature of 10% wt. and a crystallinity of 15% wt. composite slightly increased. Rheological analysis showcased that the viscosity of the composite filaments decreased compared to PLA (10–100 compared to 300–400 Pa·s), with a more shear-thinning behavior. Dynamic mechanical analysis exhibited increased elastic, flexural moduli, and flexural strength of composites (up to 16, 23, and 11%, respectively), whereas tensile strength and elongation decreased. The affordability of raw materials (with the future introduction of recycled ones) and the minimal processing steps can lead to the potential scaling up of the study. Full article

With the wide application of graphene oxide nanoparticles (GONPs), a great amount of GONP waste is discarded and concentrated in landfills. It has been proven that GONPs have strong toxicity and could gather toxic substances due to their high adsorption capacity. GONPs will seriously pollute the surrounding environment if they leak through the geosynthetic clay liner (GCL) in landfills. To investigate various factors (temperature, ionic strength (IS) and humic acid (HA)) on the transport and retention of GONPs in the GCL, a self-designed apparatus was created and column tests were carried out. The experimental results show that GONPs could be transported through the GCL. The mobility and sorption ratio of GONPs in GCL decreased with an increase in temperature and IS, and increased with an increase in HA. The temperature had little effect on the deposition ratio of GONPs in the GCL. The deposition ratio of GONPs in the GCL increased with IS, and decreased with an increase in HA. The transport of GONPs in GCL, glass beads and quartz sand was compared, and the results show that the retention ability of the GCL is much better than other porous materials. The experimental results could provide significant references for the pollution treatment in landfills. Full article

Extraction is one of the most commonly used methods for obtaining and purifying chemical compounds for commercial usage. The aim of this study was to evaluate the effect of unconventional permeabilization and cell disruption methods on the yield of lipid extraction from cells of the oleaginous yeast Yarrowia lipolytica. Batch cultures in a medium with molasses and waste post-frying oil were carried out. The biomass was subjected to pulsed electric field (PEF), high-pressure processing (HPP), ultrasounds (US), and several conventional processing techniques with chemical and mechanical agents (glass beads, acetone, Triton and Tween surfactants). The effectiveness of the applied methods, either on cell permeabilization or cell disruption, was investigated by analyzing the oil and total protein extraction yield and oil leaching efficiency, as well as by using microscope images. The PEF and US treatments proved to be effective permeabilization methods as a step of sample pretreatment for extraction. These unconventional physical methods could efficiently increase intracellular lipid extraction yield in solvent applications. Full article

Waste glass (WG), as a nonbiodegradable material, poses a threat to environmental protection. The reuse of WG as a raw material to replace cement or aggregate in concrete production is gaining attention for recycling purposes. However, the optimal proportion of WG in concrete mixtures and its particle size distribution are hard to determine. Large glass particles are prone to leading to the undesirable alkali–silica reaction (ASR) in concrete. Therefore, in this study, cement and aggregate in concrete mixtures are partially replaced by combinations of glass powder (<30 μm) and glass beads (0.2–1.7 mm), respectively. Glass concretes (GCs) containing waste glass at various replacement ratios (0, 10, 15, 20, and 30%) are prepared, and their flowability and compressive strength are evaluated and compared. Finally, steel tubes filled by ordinary concrete (OCFSTs) and steel tubes filled by glass concrete (GCFSTs) are fabricated and tested in axial compression. The test results show that the slump and slump flow increase when the replacement ratio is lower than 20%, and the maximum slump value (250 mm) is achieved for concrete with the use of 20% waste glass. With regard to compressive strength, as the glass replacement percentage is increased, the compressive strength of GC continues to reduce. The maximum decrease of compressive strength (merely 70% of compressive strength for original concrete) is observed in GC mixed with 20% glass, which might be attributed to the smooth surface of glass, consequently weakening the interfacial bond strength between the glass and matrix. In terms of the bearing capacity of GCFSTs, the axial compressive strength of GCFSTs decreases as more GC is used. However, no obvious reduction is observed compared to OCFSTs (less than 10% for GCFSTs containing 30% GP). Moreover, GCFSTs show greater (no less than 25% more) deformational ability at peak strength over OCFST columns, demonstrating that GC is a promising alternative for normal concrete. Finally, the feasibility of existing design codes (AISC, EC4, and GB50936-2014) to assess the bearing capacity of GCFSTs is evaluated by comparing the test and calculated results. The current codes, in general, give a conservative prediction and EC4 provides the closest value (predicted to experimental peak load ratio is 0.9). Full article

High-strength concrete (HSC) uses binders and microfillers with ultrafine particles, such as silica fume. The resulting dense internal hydration structure rapidly decreases HSC humidity, causing shrinkage cracks and affecting internal hydration. Herein, the hydration degree inside high-strength cement composites (HSCCs) was examined using waste glass beads (WGBs) as lightweight aggregates (LWAs). Moreover, unreacted hydrate reduction and hydrate formation tendencies were investigated. WGBs with particle sizes within 2.00–6.00 mm were added at ratios of 5%, 10%, and 20% after pre-wetting. The increased number of hydrates inside the specimens were examined under steam curing (80 °C) and room temperature curing (25 °C). The strength decreased as the WGB content increased. Thermogravimetric, X-ray diffraction, and Si nuclear magnetic resonance analyses revealed that the hydration degree of Si inside HSCCs changed when the content of pre-wetted LWAs changed. A visual inspection of the specimen cross-section and scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM–EDS) analysis revealed the moisture trapped inside WGB pores and the hydration tendency. Under steam curing and room temperature curing, the paste contained different amounts of hydrates, depending on WGB content. Moreover, water-absorbed WGBs were continuously desorbed through SEM–EDS, and hydrates were present in WGB pores. Full article

The abrasive blasting industry is identified as the most unsafe operation in terms of potential exposure to airborne crystalline silica. This is due to the free silica content in the common abrasives that are used for blasting activities. This paper will identify a sustainability-based or green blasting media to replace free silica content abrasives for blasting activities. The characteristics of sustainability-based abrasives are determined based on systematic review procedure. The combination keywords of “Abrasive blasting”, “Garnet’’, “Free Silica Media”, “Sustainable blasting”, “Eco-friendly blasting”, “Glass Bead blasting” and “Green blasting” were used to collect the existing studies on abrasive blasting operations. Six characteristics of green abrasives were identified: (1) zero content of free silica, (2) high efficiency and productivity, (3) low consumption media (4) low amount of waste generation and emission potentials (5) high recyclability and (6) environmentally friendly in line with sustainable development goals SDG3, SDG12, SDG13, SDG14 and SDG15. The application of green abrasives as substitution to free silica media is therefore important not only for safety and health reasons, but also for the environmental protection and sustainable business operations. Full article

Reproducible preparation of lithium tetraborate fused beads for XRF analysis of glass and mineral samples is of paramount importance for analytical repeatability. However, as with all glass melting processes, losses due to volatilisation must be taken into account and their effects are not negligible. Here the effects of fused bead melting time have been studied for four Certified Reference Materials (CRM’s: three feldspars, one silicate glass), in terms of their effects on analytical variability and volatilisation losses arising from fused bead preparation. At melting temperatures of 1065 °C, and for feldspar samples, fused bead melting times shorter than approximately 25 min generally gave rise to a greater deviation of the XRF-analysed composition from the certified composition. This variation might be due to incomplete fusion and/or fused bead inhomogeneity but further research is needed. In contrast, the shortest fused bead melting time for the silicate glass CRM gave an XRF-analysed composition closer to the certified values than longer melting times. This may suggest a faster rate of glass-in-glass dissolution and homogenization during fused bead preparation. For all samples, longer melting times gave rise to greater volatilisation losses (including sulphates and halides) during fusion. This was demonstrated by a linear relationship between SO₃ mass loss and time^1/2, as predicted by a simple diffusion-based model. Iodine volatilisation displays a more complex relationship, suggestive of diffusion plus additional mechanisms. This conclusion may have implications for vitrification of iodine-bearing radioactive wastes. Our research demonstrates that the nature of the sample material impacts on the most appropriate fusion times. For feldspars no less than ~25 min and no more than ~60 min of fusion at 1065 °C, using Li₂B₄O₇ as the fusion medium and in the context of feldspar samples and the automatic fusion equipment used here, strikes an acceptable (albeit non-ideal) balance between the competing factors of fused bead quality, analytical consistency and mitigating volatilisation losses. Conversely, for the silicate glass sample, shorter fusion times of less than ~30 min under the same conditions provided more accurate analyses whilst limiting volatile losses. Full article

Urban heat islands (UHI) are growing in size and intensity, which is partly attributable to the large amount of anthropogenic waste heat. Moreover, heat emitted from building exterior walls accounts for a large portion of the total anthropogenic waste heat. Thus, strategies and technologies for preventing the emission of heat from building exterior walls are being pursued by researchers worldwide. Amongst these technologies, the potential of use of retro-reflective (RR) materials instead of diffuse highly reflective (HR) materials applied to building envelopes for UHI mitigation is being studied widely. However, RR materials haven’t been applied to building envelopes in practice due to their unproven weather resistance. In order to develop RR materials with high weather resistance for application to building envelopes, two types of micro glass beads with different refractive indices (1.5, 1.9) and five different colors of base layers were evaluated in this study. Their RR performance was measured by optical experiment and compared to two types of RR sheets commercially available in Japan. The results showed that the glass bead RR samples with a refractive index of 1.9 had much higher retro-reflectivity (better RR capacity) compared to those with a refractive index of 1.5. Full article

A porous waste glass (RWPG = recycled waste porous glass) was used in wastewater treatments for the removal of lead ions from single, binary, and ternary metal solutions (with cadmium and nickel ions). Experiments were performed in columns (30 cm³, 10 g) filled with 0.5–1 mm beads till complete glass exhaustion (breakthrough). In the case of single and binary solutions, the columns were percolated at 0.2 Lh⁻¹ (2 mg Me⁺² L⁻¹); in the case of ternary solutions, the columns were percolated at 0.15–0.4 Lh⁻¹ (2 mg Me²⁺ L⁻¹) and with 2–5 mg Me²⁺ L⁻¹ influent concentration (0.2 Lh⁻¹). Lead ions were removed mainly by ion exchange and also by adsorption. From a kinetic point of view, the rate controlling step of the process was the interdiffusion of the lead ions in the Nernst stationary liquid film around the sorbent. The uptake of the metals and the glass selectivity were confirmed by Energy Dispersive X-ray spectroscopy (EDX) analysis. After lead retention process, glass beads were reused as lightweight aggregates for thermal insulating and environmental safe mortars. Full article

Low permeability clay-sand mixtures are often used to construct hydraulic barriers to prevent contaminated water leaching from landfills and other waste disposal sites from polluting local groundwater aquifers. In order to engineer effective hydraulic barriers, a proper knowledge of the hydraulic conductivity of clay-sand mixtures is required. While there are several empirical models available in the literature that can be used to predict reductions in hydraulic conductivity values of coarse sand due to the presence of clay and other fine minerals, all these models require measurement of multiple physical properties of the porous media. The resulting empirical expressions have several parameters that need to be individually evaluated using multiple soil characterization tests. In this study, we propose a single parameter model that can be used to capture the variations in hydraulic conductivity value of different types of porous media mixtures using a scalable modeling framework. Several laboratory tests were conducted to measure the hydraulic conductivity values of a variety of coarse and fine glass bead mixtures. The coarse glass beads were used to simulate sand and small glass beads were used to simulate fine minerals such as silt and clay. The model results were further validated using the data derived from experiments conducted with natural sand and clay mixtures, and also using multiple literature-derived datasets. Our results show that the proposed model is a useful tool for describing the hydraulic conductivity values of various types of coarse- and fine-grained porous media mixtures. Full article