Andre Christian Daum, Kara Johanna Drath, Harald Weigand
et al.
Despite the significant environmental impact of the healthcare sector, with Germany’s system accounting for a large proportion of national emissions, quantitative sustainability research on specific medical procedures, such as those in dentistry, is critically scarce. This study aimed to address this issue by conducting a Life Cycle Assessment to quantify and compare the Global Warming Potential of the conventional analog and the digital (intraoral scanner) impression techniques for the manufacturing of single-tooth crowns in a German dental practice. The methodology employed a cradle-to-grave approach, defining a positive dental model as the functional unit and focusing on material consumption, waste streams, and equipment usage while excluding patient travel and facility energy. The results revealed that the digital impression procedure offers significant environmental advantages, with its average carbon footprint (approx. 550 CO<sub>2</sub>-eq) being nearly threefold lower than the analog impression (approx. 1620 g CO<sub>2</sub>-eq). This difference is primarily driven by the analog impression technique’s intensive use of disposable materials and the generation of contaminated waste requiring incineration. In contrast, the digital impression’s burden shifts to the manufacturing of the intraoral scanner, highlighting the importance of high clinical utilization to achieve the ecological benefit. This work concludes that the adoption of digital impression taking is a critical step towards more sustainable dentistry by promoting material avoidance and waste reduction, provided that high equipment utilization rates can be ensured. It should be noted that these results are specific to the regional context, particularly the German energy mix and national waste management standards, and may vary in different geographical settings
Dimitrios Kalompatsios, Martha Mantiniotou, Dimitris P. Makris
This investigation aimed at studying the effect of enrichment of corn oil, which was used as a model lipid, using waste orange peel (WOP), polyphenolic antioxidants, to provide effective shielding against oxidation. An initial comparison of two modes, a stirred-tank and an ultrasound-assisted one, evidenced that the latter was more efficacious in enriching corn oil with total polyphenols. However, detailed examination of the polyphenolic composition revealed that the oil enriched with the stirred-tank mode may have almost two times higher polyphenolic content, which totaled 109 mg per kg of oil. The major polyphenolic constituents identified were polymethylated flavones, but also ferulic acid and naringenin. Oil stability trials, including the monitoring of peroxide value and <i>p</i>-anisidin value, demonstrated that the oil enriched with WOP polyphenols using the stirred-tank mode exhibited significantly higher oxidative resilience compared to control (neat oil), but also compared to the oil enriched using ultrasonication. Furthermore, it was observed that when neat oil was ultrasonicated, it also displayed exceptional stability against oxidation. Based on the outcome of this study, it is recommended that WOP, owed to its richness in lipophilic flavonoids, might be an ideal candidate for edible oil fortification, which could provide the oil with natural powerful antioxidants. Such a process could lend oils high oxidative resilience, but also functional ingredients.
Khudair Kifah M., Khudier Ahmed S., Al-Tofan Mohammed H.
Municipal solid waste (MSW) decomposition in a landfill produces what is called “landfill gas” (LFG). LFG contains methane besides other gases. It can be utilized for energy generation and, thus, reduce its emission into the atmosphere and its adverse impact on global climate. Exploitation of LFG is critical for Basrah city, Iraq (one of the hottest spots in the world) to reduce its demand for non-renewable fuels. This study aims to compare the electrical power generation potential from MSW in Basrah city adopting two scenarios: (1) LFG and (2) refuse-derived fuel (RDF) with LFG. In the first scenario, all MSW components are dumped into the landfill and the LFG is converted to energy. However, in the second scenario, only the organic wastes are dumped into the landfill and the RDF components are incinerated. Thus, energy will be produced from both the LFG and RDF. For both scenarios, LandGEM software was used for quantifying the LFG. The study results showed that the annual rates of electrical energy generation by the first and second scenarios for the period between 2022 and 2035 varied in the ranges of 4.3–9.1 MW and 26.4–36.1 MW, respectively. Therefore, the application of RDF with LFG is the better choice for electrical power generation from MSW in Basrah city.
Mark J. Wong, Viral Sagar, Mohammad Tarikuzzaman
et al.
A critical issue facing extraterrestrial expansion has always been long-term life support capabilities. The large energy requirements to move even small amounts of material from Earth necessitate the ability to reuse and recycle as much as possible, particularly waste. The weight of food supplies eventually starts to limit the length of the expedition. Hydroponic growth systems offer the ability to grow plants, and with them, a miniature ecosystem. This offers the ability to repurpose both carbon dioxide and waste salts such as ammonia and other compounds, such as those found in urine. A major issue facing hydroponic systems is the need to provide a stable water-based nutrient stream. Direct contact membrane distillation (DCMD) was tested for viability as a method of re-concentrating and stabilizing the nutrient-rich water stream. Polytetrafluoroethylene (PTFE)- and polyvinylidene (PVDF)-based polymer hydrophobic membranes were used to separate solutes from water. The DCMD method was tested with the feed stream operating at temperatures of 50 °C, 65 °C, and 80 °C. The results were analyzed using UV-Visible spectroscopy to determine concentrations. The benefits and limitations of the PTFE and PVDF membranes in DCMD were compared. The larger-pore PTFE membranes concentrated solutions effectively at 80 °C, while the PVDF membranes removed more water at lower temperatures, but permitted detectable phosphate ion leakage. Adjusting temperature and flow rates can help maintain stable ion and water transfer, benefiting hydroponic systems in achieving reliable nutrient levels.
Sergey M. Frolov, Viktor A. Smetanyuk, Anton S. Silantiev
et al.
Printed circuit boards (PCBs) are the main components of e-waste. In order to reduce the negative impact of waste PCBs on human health and the environment, they must be properly disposed of. A new method is demonstrated for recycling waste PCBs. It is referred to as the high-temperature thermo-mechano-chemical gasification (TMCG) of PCBs by the detonation-born gasification agent (GA), which is a blend of H<sub>2</sub>O and CO<sub>2</sub> heated to a temperature above 2000 °C. The GA is produced in a pulsed detonation gun (PDG) operating on a near-stoichiometric methane–oxygen mixture. The PDG operates in a pulsed mode producing pulsed supersonic jets of GA and pulsed shock waves possessing a huge destructive power. When the PDG is attached to a compact flow reactor filled with waste PCBs, the PCBs are subject to the intense thermo-mechano-chemical action of both strong shock waves and high-temperature supersonic jets of GA in powerful vortical structures established in the flow reactor. The shock waves grind waste PCBs into fine particles, which undergo repeated involvement and gasification in the high-temperature vortical structures of the GA. Demonstration experiments show full (above 98%) gasification of the 1 kg batch of organic matter in a setup operation time of less than 350 s. The gaseous products of PCB gasification are mainly composed of CO<sub>2</sub>, CO, H<sub>2</sub>, N<sub>2</sub>, and CH<sub>4</sub>, with the share of flammable gas components reaching about 45 vol%. The solid residues appear in the form of fine powder with visible metal inclusions of different sizes. All particles in the powder freed from the visible metal inclusions possess a size less than 300–400 μm, including a large fraction of sizes less than 100 μm. The powder contains Sn, Pb, Cu, Ni, Fe, In, Cd, Zn, Ca, Si, Al, Ti, Ni, and Cl. Among these substances, Sn (10–20 wt%), Pb (5–10 wt%), and Cu (up to 1.5 wt%) are detected in the maximum amounts. In the powder submitted for analysis, precious elements Ag, Au, and Pt are not detected. Some solid mass (about 20 wt% of the processed PCBs) is removed from the flow reactor with the escaping gas and is partly (about 10 wt%) trapped by the cyclones in the exhaust cleaning system. Metal inclusions of all visible sizes accumulate only in the flow reactor and are not detected in powder samples extracted from the cyclones. The gasification degree of the solid residues extracted from the cyclones ranges from 76 to 91 wt%, i.e., they are gasified only partly. This problem will be eliminated in future work.
This study investigates key demographic and behavioural factors influencing food waste behaviours among Greek consumers, offering insights into effective waste reduction strategies. Using k-means clustering, Greek consumers were segmented into three groups based on data from a structured online survey: ‘Moderate Consumers’, who demonstrate moderate awareness of food waste but lack consistent practices; ‘Indifferent Consumers’, primarily younger urban residents, with limited concern and significant contributions to waste; and ‘Conscious Consumers’, generally older individuals with structured habits that actively minimise waste. The findings reveal distinct engagement levels across these groups, highlighting the importance of tailored interventions. Conscious Consumers can serve as community advocates for sustainable practices, while Indifferent Consumers require targeted awareness campaigns to foster engagement. Moderate Consumers, with their sporadic efforts, could benefit from practical tools such as meal-planning apps. By exploring these unique consumer profiles, this research provides a culturally contextualised understanding of food waste attitudes in Greece and lays the groundwork for designing targeted strategies to encourage sustainable consumption.
Lignocellulosic biomass, including agricultural, forestry, and energy crop waste, is one of Earth’s most abundant renewable resources, accounting for approximately 50% of global renewable resources. It contains cellulose, hemicellulose, and lignin, making it crucial for biofuels and bio-based chemicals. Due to its complex structure, single-pretreatment methods are inefficient, leading to the development of combined pretreatment technologies. These methods enhance cellulose accessibility and conversion efficiency. This paper analyzes the principles, advantages, and disadvantages of various combined pretreatment methods and their practical benefits. It highlights recent research achievements and applications in biofuel, biochemical production, and feed. By integrating multiple pretreatment methods, biomass degradation efficiency can be significantly improved, energy consumption reduced, and chemical reagent use minimized. Future advancements in combined physical, chemical, and biological pretreatment technologies will further enhance biomass utilization efficiency, reduce energy consumption, and protect the environment, providing robust support for sustainable renewable energy development and ecological protection.
The main thrust of the current study is to examine the effects of ground granulated blast-furnace slag (GGBS), pulverized fuel ash (PFA), and bi-combination of GGBS and PFA on the mechanical properties of concrete. Seven concrete mixes were carried out in this study; including the control mix and the other six mixes had supplementary cementitious materials (GGBS, and PFA) as partial replacement of Portland cement at different replacement levels. The physical properties, oxides, and chemical composition of OPC, GGBS and PFA were experimentally investigated. The workability of the fresh concrete mixes was carried out by means of slump test and compaction index test. This study also examined the compressive strength of the different concrete mixes at different curing ages along with the splitting tensile strength. Cost analysis and the environmental impact of the different concrete mixes was also evaluated. The study results showed that the workability was significantly improved through the replacement of cement with PFA and GGBS. The utilisation of fly ash at 30% replacement level achieved the highest workability. The highest compressive strength was achieved by concrete mixes replacing 30% GGBS with cement, and a bi-combination of 10% PFA and 20% GGBS. The results also showed that the bi-combination of fly ash and GGBS at 10% and 20% replacement level was found to be favorable in terms of both cost and environmental impact.
Abstract Plastics are non-biodegradable, strong, durable, moisture resistant, light weight polymers of carbon along with hydrogen, nitrogen, sulphur, and other organic and inorganic elements and are manufactured from fossil fuel which is a non-renewable source. Low density polyethylene is the most commonly occurring non-biodegradable waste material which constitutes approximately 60% of the total plastic production. In the present study, an attempt has been made to isolate, screen, and characterize the most efficient polyethylene degrading bacteria by using partially degraded polyethylene samples with adhered soil collected from two municipal waste dumping grounds of Jammu region. A total of 62 bacterial isolates were obtained from different waste disposal sites were screened on synthetic Medium. Low density polyethylene powder was used as the sole carbon source in synthetic medium. The biodegradation activity of the isolates was investigated based on the percent weight loss and percent loss in tensile strength of the polyethylene. Maximum percent weight loss (%WL; 22.66) was recorded with MB57 after 2 months of shaking at room temperature. Maximum percent loss in tensile strength (% loss in TS; 74.35) was documented MB57. Further, the level of degradation was confirmed by scanning electron microscopic (SEM) analysis. In SEM analysis, scions/ crakes were found on the surface of the degraded polyethylene.
Ioannis Varvaringos, Eva Skourtanioti, Georgios Letsos
et al.
Sustainable bioeconomy is a promising pathway towards the transition to a circular and climate-neutral economy. The valorization of biowaste is a key player in this direction. This paper presents the design and development of the AgriPLaCE Platform, which aims to promote synergies that enable the utilization of biowaste from the fruit and vegetable supply chain. The platform consists of the AgriPLaCE Waste Management Database, which provides users with an extended list of potential utilization methods for various types of fruit and vegetable biowaste streams, and the AgriPLaCE Synergies Tool, which facilitates synergies between different actors involved in the biowaste-to-resource value chain from agricultural waste production to waste treatment and new valuable products’ exploitation. Initially, the conceptual design of both tools took place based on analysis of user needs and services alongside the system architecture. Following this, the AgriPLaCE Platform was developed with the implementation of all the necessary subsystems. The results of the platform’s implementation demonstrated its potential to generate multiple collaborations and synergies while users can also deepen their knowledge about alternative and emerging treatment technologies and valuable products from a wide range of fruit and vegetable biowaste streams.
Alistair F. Holdsworth, Harry Eccles, Clint A. Sharrad
et al.
Nuclear fuel is both the densest form of energy in its virgin state and, once used, one of the most hazardous materials known to humankind. Though commonly viewed as a waste—with over 300,000 tons stored worldwide and an additional 7–11,000 tons accumulating annually—spent nuclear fuel (SNF) represents a significant potential source of scarce, valuable strategic materials. Beyond the major (U and Pu) and minor (Np, Am, and Cm) actinides, which can be used to generate further energy, resources including the rare earth elements (Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, and Tb), platinum group metals, (Ru, Rh, Pd, and Ag), noble gases (He, Kr, and Xe), and a range of isotopes useful for medical and energy generation purposes are also produced during fission. One reason for the accumulation of so much SNF is the low uptake of SNF recycle (or reprocessing), primarily due to the high capital and operational costs alongside concerns regarding proliferation and wastes generated. This study will highlight the predominantly overlooked potential for the recovery of strategic materials from SNF, which may offset costs and facilitate advanced waste management techniques for minimised waste volumes, thus increasing the sustainability of the nuclear fuel cycle on the path towards Net Zero. Potential challenges in the implementation of this concept will also be identified.
Regenerative Robust Gasification promises to convert unsorted organic waste, including all plastic waste, into the fungible, primary feedstock chemical methanol. As the backbone of the C1 chemical industry, methanol has broad application in circular economy chemical synthesis. This paper summarizes traditional and newer approaches for producing methanol from synthesis gas. Approaches, methods, reaction mechanisms, catalyst systems, catalyst synthesis methods, reactor types, and many other aspects are summarized.
Audrey Lallement, Christine Peyrelasse, Camille Lagnet
et al.
Agricultural biogas plants are increasingly being used in Europe as an alternative source of energy. To optimize the sizing and operation of existing or future biogas plants, a better knowledge of different feedstocks is needed. Our aim is to characterize 132 common agricultural feedstocks in terms of their chemical composition (proteins, fibers, elemental analysis, etc.) and biochemical methane potential shared in five families: agro-industrial products, silage and energy crops, lignocellulosic biomass, manure, and slurries. Among the families investigated, manures and slurries exhibited the highest ash and protein contents (10.3–13.7% DM). High variabilities in C/N were observed among the various families (19.5% DM for slurries and 131.7% DM for lignocellulosic biomass). Methane potentials have been reported to range from 63 Nm<sup>3</sup> CH<sub>4</sub>/t VS (green waste) to 551 Nm3 CH<sub>4</sub>/t VS (duck slurry), with a mean value of 284 Nm<sup>3</sup> CH<sub>4</sub>/t VS. In terms of biodegradability, lower values of 52% and 57% were reported for lignocelluloses biomasses and manures, respectively, due to their high fiber content, especially lignin. By contrast, animal slurries, silage, and energy crops exhibited a higher biodegradability of 70%. This database will be useful for project owners during the pre-study phases and during the operation of future agricultural biogas plants.
This review provides an overview of the biotransformation of limonene and α-pinene, which are commonly found in wood residues and citrus fruit by-products, to produce high-value-added products. Essential oils derived from various plant parts contain monoterpene hydrocarbons, such as limonene and pinenes which are often considered waste due to their low sensory activity, poor water solubility, and tendency to autoxidize and polymerise. However, these terpene hydrocarbons serve as ideal starting materials for microbial transformations. Moreover, agro-industrial byproducts can be employed as nutrient and substrate sources, reducing fermentation costs, and enhancing industrial viability. Terpenes, being secondary metabolites of plants, are abundant in byproducts generated during fruit and plant processing. Microbial cells offer advantages over enzymes due to their higher stability, rapid growth rates, and genetic engineering potential. Fermentation parameters can be easily manipulated to enhance strain performance in large-scale processes. The economic advantages of biotransformation are highlighted by comparing the prices of substrates and products. For instance, R-limonene, priced at US$ 34/L, can be transformed into carveol, valued at around US$ 530/L. This review emphasises the potential of biotransformation to produce high-value products from limonene and α-pinene molecules, particularly present in wood residues and citrus fruit by-products. The utilisation of microbial transformations, along with agro-industrial byproducts, presents a promising approach to extract value from waste materials and enhance the sustainability of the antimicrobial, the fragrance and flavour industry.
Arthur Chevalier, Philippe Evon, Florian Monlau
et al.
This study aimed to evaluate the effects of mechanical treatment through twin-screw extrusion for the enhancement of biomethane production. Four lignocellulosic biomasses (i.e., sweetcorn by-products, whole triticale, corn stover and wheat straw) were evaluated, and two different shear stress screw profiles were tested. Chemical composition, particle size reduction, tapped density and cellulose crystallinity were assessed to show the effect of extrusion pretreatment on substrate physico-chemical properties and their biochemical methane production (BMP) capacities. Both mechanical pretreatments allowed an increase in the proportion of particles with a diameter size less than 1 mm (from 3.7% to 72.7%). The most restrictive profile also allowed a significant solubilization of water soluble coumpounds, from 5.5% to 13%. This high-shear extrusion also revealed a reduction in cellulose crystallinity for corn stover (i.e., 8.6% reduction). Sweetcorn by-products revealed the highest BMP values (338–345 NmL/gVS), followed by corn stover (264–286 NmL/gVS), wheat straw (247–270 NmL/gVS) and whole triticale (233–247 NmL/gVS). However, no statistical improvement in maximal BMP production was provided by twin-screw extrusion. Nevertheless, BMP kinetic analysis proved that both extrusion pretreatments were able to increase the specific rate constant (from 13% to 56% for soft extrusion and from 66% to 107% for the high-shear one).
Landfills receive about 350 million tons of municipal solid wastes (MSWs) per year globally, including antibiotics and other coselecting agents that impact antimicrobial resistance (AMR). However, little is known about AMR in landfills, especially as a function of landfill ages. Here we quantified antibiotics, heavy metals, and AMR genes (ARGs) in refuse and leachates from landfills of different age (20 years). Antibiotics levels were consistently lower in refuse and leachates from older landfills, whereas ARG levels in leachates significantly increased with landfill age (One-way ANOVA, F = 10.8, P < 0.01). Heavy metals whose contents increased as landfills age (one-way ANOVA, F = 12.3, P < 0.01) were significantly correlated with elevated levels of ARGs (Mantel test, R = 0.66, P < 0.01) in leachates, which implies greater AMR exposure risks around older landfills. To further explain ARGs distributional mechanisms with age, microbial communities, mobile genetic elements (MGEs) and environmental factors were contrasted between refuse and leachate samples. Microbial communities in the refuse were closely correlated with ARG contents (Procrustes test; M2 = 0.37, R = 0.86, P < 0.001), whereas ARG in leachates were more associated with MGEs.
Plastic has invaded the rural Andean landscape in recent decades. Its increase is due to the emergence of new consumption patterns, the absence of adequate waste management systems, and the persistence of a logic that incorporates waste into nature—which was appropriate when waste was biodegradable. However, the rural indigenous population is aware of plastic’s polluting effects. Tourism, which transmits urban and Western perceptions of cleanliness, is one of the factors that have led to this view. Tourism spreads an ecological perception that supports the sustainability of natural resources. It also spreads a bucolic perception of the landscape. Sometimes, the two discourses complement each other, but they can also clash. From the discard studies paradigm, and based on the case of Amantaní Island (Lake Titicaca, Peruvian Andes), the article shows that tourist demand for a pristine landscape can drive practices that increase the environmental and health risks of plastic waste.
Municipal refuse. Solid wastes, Standardization. Simplification. Waste
Anne Shayene Campos de Bomfim, Daniel Magalhães de Oliveira, Eric Walling
et al.
As an everyday beverage, coffee is consumed worldwide, generating a high amount of waste after brewing, which needs attention for its disposal. These residues are referred to as spent coffee grounds (SCGs), which have been shown to have applications as polymers/composites precursors, biofuels, and biofertilizers. This review focuses on agricultural applications usually based on organic matter to fertilize the soil and consequently improve plant growth. To date, SCGs have been shown to exhibit outstanding performance when applied as soil amendment and composting because it is a nutrient-rich organic waste without heavy metals. Therefore, this review presents the different options to use SCGs in agriculture. First, SCG composition using different characterization techniques is presented to identify the main components. Then, a review is presented showing how SCG toxicity can be resolved when used alone in the soil, especially at high concentrations. In this case, SCG is shown to be effective not only to enhance plant growth, but also to enhance nutritional values without impacting the environment while substituting conventional fertilizers. Finally, a conclusion is presented with openings for future developments.