Journal of Material Cycles and Waste Management最新文献

Universities function as small-scale models of cities, consuming significant resources and generating considerable waste. This study, therefore, focused on the determination of the quantity, composition, and recycling potential of solid waste generated at eight universities across Türkiye over an academic year. Results revealed that 78% of total waste is recyclable, indicating significant potential for implementing integrated waste management systems. The average daily waste generation per university was 2,588.1 kg, with major components being paper and cardboard (27.77%, 718.72 kg/day), organic waste (15.90%, 411.50 kg/day), plastics (19.40%, 502.09 kg/day), metals (7.14%, 184.79 kg/day), glass (7.77%, 201.10 kg/day), and non-recyclable materials (22.02%, 569.90 kg/day). These findings highlight the importance of waste characterization for the development of sustainable waste management strategies. Emphasizing waste reduction, reuse and recycling can contribute to reduce the overall environmental impact of universities. The study provides a baseline data set that can support the development of tailored, data-driven waste management programs to improve resource efficiency and sustainability in universities.

Portland cement (PC) is extensively employed in the construction industry, but carries large environmental and energy expenses via the release of greenhouse gases. Geopolymer concrete GPOC), a product manufactured using sustainable materials such as fly ash (FLY), ground granulated blast furnace slag (GGBFS), and recycled coarse aggregate (RCA), offers a more environmentally friendly option. A cradle-to-site life cycle assessment (LCA) of 27 GPOC mixes found that increased GGBFS content and NaOH molarity significantly minimize embodied energy and global warming potential (GWP) while maximizing sustainability. Further addition of RCA content decreases energy consumption, but increases cost through processing. The best mix—50% GGBFS, 8M NaOH, and regular coarse aggregate—obtained a well-balanced environmental and economic performance with a desirability score of 0.25. These results affirm the position of GPOC in sustainable building, providing industry players with significant information for green and affordable building options.

This study investigated the influence of waste pistachio shell (WPNS), tea leaf (WTLF), and quail eggshell (WQES) fillers on the mechanical, thermal, tribological, and acoustic properties of hybrid jute-reinforced polylactic acid (PLA) composites. Eight composite formulations were prepared using compression molding, incorporating varying compositions of jute fibers and biofillers. The results revealed that the incorporation of 7.5 wt. % of these fillers significantly enhanced the composite's overall performance. Sample S7 (containing WTLF) exhibited the highest sound absorption coefficient (SAC) of 0.643, followed by S8 (WQES, SAC = 0.578) and S6 (WPNS, SAC = 0.485), indicating the effectiveness of the filler-induced porous structures in improving acoustic damping. XRD analysis confirmed that WQES had the highest crystallinity index and crystallite size, which contributed to its superior mechanical reinforcement capabilities. SEM analysis provided evidence of enhanced interfacial bonding in the WQES composites, whereas the WPNS and WTLF composites exhibited a more porous and tortuous morphology, facilitating better sound absorption. The hybrid composites also demonstrated improved tensile strength, flexural strength, and impact resistance compared with pure PLA. Sample S6 (Jute/PLA/WPNS) exhibited the highest tensile (57.38 MPa) and flexural (114.67 MPa) strengths, whereas S7 (Jute/PLA/WTLF) showed the highest impact strength (4.35 kJ/m²). The incorporation of WQES significantly reduced water absorption and improved flame retardancy, with S5 (WQES/PLA) exhibiting the lowest water absorption (0.588%) and the best flame resistance (UL 94 V-0 rating). These findings highlight the potential of these sustainable biofillers for developing high-performance composites with balanced mechanical and acoustic properties for various applications, including noise-reducing panels, automotive interiors, and structural components.

Composted green waste (CGW) is an emerging alternative material for seedling substrate. However, its high salinity, bulk density, low porosity, and nutrient imbalance limit its application for seedling cultivation. This study investigated the effects of adding sawdust (0%, 20%, and 50%) and vermiculite (0%, 15%, and 25%) on the physicochemical properties of CGW and its suitability as a substrate for cruciferous vegetable seedlings. The combined amendment of 20% sawdust and 15% vermiculite significantly improved aeration porosity, water-holding porosity, total phosphorus, total potassium, and humic acid content by 5.9%, 3.9%, 43.9%, 5.1%, and 7.5%, respectively, compared to the unamended control (p ≤ 0.05). Seedlings of Brassica rapa (Chinese cabbage), Brassica chinensis (Shanghai qing), and Brassica rapa var. parachinensis (Choy sum) exhibited the highest germination energy under this exhibited substrate. Relative to unamended CGW, the germination energy of Chinese cabbage, Shanghai qing, and Choy sum increased by 21%, 200%, and 100%, respectively. Redundancy analysis, coupled with comprehensive assessment of plant morphological traits, confirmed that CGW amended with 20% sawdust and 15% vermiculite constitutes an optimal substrate formulation for cruciferous seedling production.

Compostable pre-collection plastic bags can foster the separate collection of biowaste from households and reduce pollution of conventional plastics. Test conditions proposed in certification procedures (e.g., EN 13432) used to show the compostability of such materials (and products) are made under controlled and optimal laboratory conditions and extended test periods that are rarely achieved in the composting practice. Thus, it is possible that some ‘compostable’ plastic products may not be degraded satisfactorily in technical composting plants under realistic conditions, which could leave microplastic fragments in composts. Therefore, in this study, the compostability of a certified compostable plastic bag was investigated under practical conditions in two state-of-art composting plants in Austria. Expected future plastic bag quantities (resulting in 0.95–1.19 kg biowaste per pre-collection-bag) were added to test windrows and were investigated during 12 weeks for fragment sizes > 0.2 mm. The results show that the investigated materials degraded within the first four weeks and left only tiny amounts of plastic materials in a size range 0.63–0.2 mm.

Vietnam faces pollution control problems associated with landfills, along with increasing difficulties in the acquisition of land for waste disposal. This study aimed to characterize landfills in a built database and prioritize measures based on land use-focused assessment, thereby facilitating strategies to enhance landfill management. Of the 4421 landfills nationwide, only 443 were sanitary (10%) and a majority (98.6%) were small, with < 1-ha landfills accounting for 86.6% of the total. The area for sanitary landfilling accounted for 39% of the total area. Landfills are generally poorly located, designed, and operated, and encounter increasing risks owing to climate change. Land use-focused assessment revealed that 90% of provinces did not meet the regulated limit of the calculated land use rate, implying improper utilization of land for waste landfilling. Benchmarking was employed to prioritize the proposed measures, revealing the highest prioritization for the combined measure of dumpsite cleanup and Waste-to-Energy (WtE) incineration. The adoption of prioritized measures could help narrow 39.4% (1524 ha) of the dumping area that must be reduced by the target years. These findings provide efficient measures to address landfill-associated challenges, support the adopted strategies with better resource allocation, and benefit other developing countries with referable evidence and waste databases.

Land application of biosolids for soil conditioning is a promising pathway to promote sustainability, especially in developing countries such as the Philippines. To maximize its benefits, heavy metals, pathogens, and emerging pollutants that come with biosolids must be properly managed using appropriate treatment processes. Furthermore, environmental impacts and associated costs when investing and operating on technologies must be considered. This study utilizes analytic hierarchy process to compute for priority weights for the following technologies: in-vessel composting, heat drying, electron beam irradiation and gamma ray irradiation. Weights for the 10 subcriteria were obtained through a pairwise comparison made by 45 wastewater professionals, which were then used to assess the four technologies. Based on the data and responses obtained, gamma ray irradiation emerged as the top technology among the technology options. However, in-vessel composting still remains an important option especially when more importance is given to vector attraction reduction, local technology readiness level (TRL), and operational expenses (OPEX).

Activated sludge is a key component in wastewater treatment processes as it contains the microbes responsible for treatment. Autotrophic and heterotrophic bacteria perform breakdown complex organic matter and denitrify the water using carbon sources as their energy requirement. As the existing carbon source in effluent wastewater is often insufficient to support complete denitrification, external carbon sources are added to make up for this deficit. In this paper, different carbon sources and biofilm carriers were reviewed, and the uses of ionizing radiation were discussed. The potential of ionizing radiation as a way to integrate carbon sources from denitrification sludge into biofilm carriers was then explored. The production of radicals after irradiation leads to a more reactive biofilm carrier surface, promoting the attachment of charged biofilm and the growth of sludge. The breakdown of complex carbon molecules in the sludge into simpler molecules after irradiation allows it to be used by microbes as a carbon source and continue. With the theoretical foundations offered by this study, proof-of-concept studies are then recommended to confirm the effect of sludge irradiation on biofilm attachment and denitrification performance.

Glycerol is a commonly obtained as a by-product from biodiesel. Glycerol finds its use as a precursor for many reactions and leads to variety of products. The current review presents a reaction network of all the possible routes and the products obtained from glycerol along with the market scenario of these products. Acetylation of glycerol gives acetins; mono, di and triacetin. Acetins have widespread application in perfumery, cosmetics, pharmaceuticals, fast-moving consumer goods (FMCG), and as additives to fuel sector. Acetylation is one of the highly studied route, with over two decades of study by the scientific community presenting profusely the performance of different catalysts; this route has been extensively reviewed in the study. The catalysts are critically evaluated to provide the guideline for further research. The current review is intended to give an update on the catalyst development, its performance, along with opportunities in the field that can be explored.

Reliable waste estimates are fundamental for developing efficient waste management strategies by promoting resource efficiency and sustainable construction practices. Although various researchers have developed methods and tools globally to estimate waste, there is a dearth of focused research which integrates the past studies to understand the growing trend and evolution on the subject, which can help identify under-explored or neglected areas. This study uses a science mapping approach to analyze construction waste estimation methods literature. First, bibliometric search of the Scopus database (2000–2024) identified relevant articles. Then for the scientometric analysis, VOSviewer version (v1.6.20) was used to identify and analyze the publication trends, active countries, influential journals and authors and keywords that contributed the most in the waste estimation research globally. Results show that only 10 countries have published more than 2 articles in the past, with China leading the research. Concrete, construction stages, machine learning, prediction model and residential buildings are the top 5 emerging keywords. Information management, predictive modeling, classification and composition and material data modeling are the top emerging research themes deduced by an in-depth qualitative assessment. The results highlighted a rising interest in adoption of BIM and AI tools in waste estimation methods. This study overviews the latest research in construction waste estimation methods, serving researchers and industry professionals by identifying current gaps and future research directions and practical implications.