Journal of Material Cycles and Waste Management最新文献

Fenton sludge containing (20–40% iron content) is produced by Fenton oxidation technology during the treatment of refractory organic pollutants, which is a hazardous industrial waste. Moreover, the landfill and incineration of Fenton sludge result in the waste of iron resources. In this context, Fenton sludge obtained from the advanced treatment of papermaking wastewater was mixed with coal slime and coal fly ash to prepare water treatment fillers via a high-temperature sintering. Specifically, the effects of raw material ratio, sintering temperature and sintering time on the filler properties were analyzed, including compressive strength, bulk density and water absorption of capacity, and the optimum process conditions were determined. It was confirmed that under the optimal process conditions of Fenton sludge: coal fly ash: coal slime = 5:3:2, sintering temperature 950 ℃, sintering time 40 min, preheating temperature 400 ℃ and preheating time 30 min. The analysis was carried out on the physical properties, the leaching concentration of heavy metals, micromorphology, phase composition and element content of the fillers. Under the conditions of pH 3, m(COD_Cr):m(H₂O₂) 1:1.5, catalyst dosage 15 g L⁻¹, reaction time 100 min, COD_Cr reduced to 48.65 mg L⁻¹.

Carbon dioxide emissions pose a global issue, with deforestation, forest loss from logging, fires, and construction highlighting the adverse effects of climate change. Urgent action is required to reduce carbon dioxide emissions and preserve forests. Egypt can contribute to reducing greenhouse gas emissions by effectively utilizing its waste resources, especially agricultural waste. The research focuses on developing environmentally friendly and sustainable construction materials with a forward-looking approach. This involves exploring alternative options for synthetic formaldehyde adhesives. This assessment emphasizes the significance of sustainability in the construction sector. The mechanical properties of the developed construction materials demonstrate higher tensile strength and Young's modulus values of 6.95 and 2493.5, respectively. An environmental impact assessment (EIA) was conducted for the production process of manufactured building materials, using 1000 kg of cotton stalk waste, and employing “open LCA software”. The assessment includes impact categories such as ecological footprint, greenhouse gas protocol, impact 2002 +, CML IA baseline, and ecosystem damage potential. Results indicate an impact of 179.411 kg of CO2 on global warming and a total ecological footprint of 2382.1722 m²a. The study also considers other impact categories, including carcinogens, respiratory organics, aquatic and terrestrial ecotoxicity, human toxicity, and land occupation and transformation.

Organic matters such as food and kitchen scraps are inevitable wastes generated from daily domestic activities. Managing these at source can help the government's environmental endeavors, such as waste minimization and diversion. This study analyzes the performance, economic, and environmental impact of a community-based design compost processor (CBCP). This paper measured various compost parameters and utilized scenario-based analysis for the economic viability while IGES-GHG simulator was used for its environmental impact. Results showed that the composting process lasted 30 days with temperature, pH, moisture, and quality of output falls into standard. The decentralized composting using CBCP could be a worthwhile economic business model and an essential ecological endeavor for climate change mitigation. About 27% of methane (CH₄) reduction yielding 209.72 Gg CO₂ equivalent are potentially removed in landfills if biowastes are diverted due to the degradation process. The annual overall net GHG emission of -11,913 Gg of CO₂ equivalent means substantial positive impact to the environment. With these, local government units need to recognize the importance of producing compost from biowaste. However, sustainability of such projects depends on stakeholders' willingness, motivation, community's available resources, and government support.

Graphical Abstract

This research explores sustainable usage of waste fabric, specifically knitted three-thread polyester fleece fabric (3-TPEF), to reinforce epoxy. Different orientations of the fabric (wale and course), varying weight proportions, and fibers derived from the fabric are studied. The impact of unmodified and epoxy-functionalized glass microspheres (UGM and FGM) on the mechanical and thermo-mechanical properties of composites is investigated. Custom-made mold was utilized to regulate fabric weight, reduce air traps, and collect surplus resin released during compression. Compared to neat epoxy, FGM-incorporated fabric-reinforced composites exhibit increased tensile strength (43 vs. 51 MPa), tensile modulus (2.2 vs. 3.5 GPa), flexural strength (83 vs. 98 MPa), flexural modulus (2.9 vs. 4.3 GPa), and impact strength (20 vs. 26 kJ/m²). Weight loss during decomposition decreased from 76.9% (neat epoxy) to 57.7% (composite), indicating improved thermal stability. Dynamic mechanical analysis shows a 1.5-fold increase in relative loss modulus area and tan-δ area, highlighting the improved damping and energy-dissipation capabilities. Moldability and formability involved in the fabrication were demonstrated by manufacturing brake levers and decorative wall panels using 3D-printed mold and wire mesh. The enhanced performance of composites fabricated through this sustainable circular economy approach makes them suitable for automotive and construction applications.

As global vehicle production increases, the need for sustainable practices in the automotive sector grows. Despite efforts to promote circular practices like mechanical recycling, the complexity of automotive plastic parts presents challenges. This study investigated the relationship between processing sequence and the mechanical, thermal, and rheological properties of painted and unpainted post-consumer automotive bumpers. Injection-molded specimens of ground unpainted and painted bumpers were obtained with or without previous extrusion. The studied recycled bumpers comprised a PP matrix with ethylene-propylene rubber phase copolymer and talc filler. The results highlighted a significant contribution of this study: the paint coating protected PP-based bumpers from chemical degradation during use, while finely dispersed paint particles within the PP matrix could potentially mitigate thermo-mechanical degradation during extrusion. The pre-extrusion did not enhance mechanical performance. A positive outcome of this study was that simplifying processing steps can optimize efficiency, reduce energy consumption, and increase sustainability, offering a positive outlook for future endeavors in recycled material utilization.

Expanded polystyrene (EPS) is one of major plastic pollutants which toxicity increased when exposed to UV irradiation. In this study, the feasibility of upcycling waste EPS (WEPS), which originates from food packaging, into a flat-sheet filtration membrane was explored. The membrane was fabricated using the wet-phase inversion method, with polyimide serving as a blending additive varied from 2 to 8 wt.%. Characterization was carried out using water contact angle measurements, SEM, and UV–Vis spectrophotometry. The experimental results indicated that all WEPS/PI membranes demonstrated microplastic rejection rates exceeding 80%, and they exhibited greater uniformity compared to the pristine WEPS membrane. Furthermore, protein rejection improved with the concentration of PI. The addition of 8 wt.% polyimide led to a 240% increase in protein rejection, with all membranes having hydrophilic surface. The SEM images revealed that the introduction of polyimide altered the membrane’s structure, enhancing its filtration properties by modifying the finger-like structure of the membrane. The addition of 8% polyimide to the WEPS dope solution decreased both pore size and porosity to the least value observed, while also enhancing the antifouling property by 67%. The experimental findings indicate that the WEPS/PI membrane holds significant promise to solve challenges of waste EPS accumulation, as well as offering sustainable solutions for addressing microplastic pollution by recycling the waste EPS into high-end filtration membrane.

The increasing depletion of natural clay resources and the indiscriminate dumping of solid waste has exerted unprecedented pressure on the environment. This study primarily aims to assess the efficacy of waste glass (WG) in enhancing the compressive strength of sludge-shale bricks. The mass loss (ML), apparent porosity (AP), bulk density (BD), water absorption (WA), and compressive strength (CS) of the sludge-shale bricks were evaluated in accordance with the relevant Chinese standards. The optimal parameters were determined to be a WG dosage of 30%, a molding pressure of 20 MPa, a sintering temperature of 1000 °C, and a holding time of 2 h. The performance of the products under optimum conditions was further evaluated through freeze–thaw tests, leaching tests, microstructural and mineralogical analysis. The results indicated that the AP, BD, WA, and CS of sludge-shale bricks prepared under optimum conditions were 35.31%, 1.69 g/cm³ and 15.29% 52.01 MPa, respectively. Leaching tests revealed that incorporating WG and elevation of sintering temperature enhance the efficacy of heavy metal immobilization. Following 25 freeze–thaw cycles, weight loss values for all sludge-shale bricks remained considerably below national limits. Elevated WG dosage and sintering temperature promote structure vitrification and densification, facilitating anorthite formation that enhances CS. This study provides robust data support for the synergistic preparation of sintered bricks using shale, municipal sewage sludge (MSS) and WG.

Graphical abstract

The increasing production of waste electrical and electronic equipment (WEEE) in Brazil is driving the adoption of circular economy (CE) practices related to the management of the WEEE reverse chain. Thus, the adoption of CE becomes essential for strategic management that promotes environmental preservation, and economic and social development. This study, which employed a survey as the research method, aims to evaluate the importance of CE practices related to the management of the WEEE reverse chain in Brazil. To achieve this, we employed the Kruskal–Wallis and Holm-Sidak multiple comparison tests. Based on the obtained results, the most significant practices are related to legislation and regulations, and effective consumer participation. These are followed by practices related to the management of outsourced recycling companies, and the involvement of logistics operators, treatment, and recycling strategies. The least representative practices were simulations and optimization strategies for logistics transportation, collection centers, and recycling centers. This study contributes to managerial practice by suggesting trends related to environmental management practices and material circularity, as well as compliance with the National Solid Waste Policy. For society, the research highlights the need for consumer education regarding the disposal of WEEE, as well as the necessity for governments and companies to collaborate in forming cooperatives.

This study assessed students’ awareness and inclination towards solid waste segregation for recycling and the potential determinants of student’s willingness to participate in waste segregation initiative in the future. The objective was to obtain vital information that can be used in planning for implementation of solid waste segregation for circular economy in schools in the Yilo Krobo and Lower Manya Krobo Municipals in southeastern Ghana. Using semi-structured questionnaire, 1656 students were randomly selected and interviewed across secondary and tertiary schools in the two municipalities for data collection and analysis. Awareness among students about solid waste segregation, including the benefits associated with the practices, was high. Basically, the majority of the students were willing to participate in any solid waste segregation projects in the future if (i) waste bins are located in their classrooms, (ii) clear instruction is indicated on waste bins and/or (iii) students are educated on waste segregation practices. Almost all the students were willing for their schools to pay for collection and recycling of their segregated solid wastes. However, ordinal logistic regression analysis revealed that placing well-labelled waste bins within schools is the most significant determinant to increase students’ willingness to segregate wastes for the intended initiatives.

Linear agricultural nutrient regimes are the principal cause for perturbation of the geochemical cycles for nitrogen (N) and phosphorus (P) and other planetary boundaries. Nutrient cycles are characterized by high spatial disparity and China is a hotspot due to high fertilizer application rates. Using substance flow analysis, this study identified and quantified nutrient flows from agricultural production to residue management of Huangyan tangerines (Citrus reticulata) and water bamboo (Zizania latifolia) in a case study of Huangyan district (Taizhou City, Zhejiang province). About 754 Mg/a of N and 105 Mg/a of P can theoretically be recovered in the tangerines and water bamboo systems from currently untapped material flows. This could replace 59% of the N and 15% of the P currently applied as chemical fertilizer, reducing environmental impacts. Combining the nutrient recovery of both systems and upscaling the results to Taizhou City, the goal from the 14th Five-Year Plan for Agricultural and Rural Modernization to save 1182 Mg of nutrients per year could be exceeded by almost 12 times. This study’s data have varying degrees of uncertainty. The analysis of data representativeness shows potential for improvements, especially in the agricultural production of water bamboo and the nutrient contents of material flows.