Waste Generation Research Articles

A thorough overview of the literature on waste recycling in the circular economy: current practices and future perspectives.

To develop a circular economy (CE) and protect the environment, waste recycling (WR) is crucial. This study examines WR research conducted over the past two decades to identify the most significant advancements and promising areas for future research. The following challenges were handled through text mining, content, and bibliometrics analysis: How has CE influenced the evolution of WR research? What are the CE's most important WR research trends and themes? What directions could future research on WR take regarding the CE transition? Using 1118 articles from the Scopus database journal, bibliometric networks were made and analyzed. Hence, five critical CE-related problems needing further research were recognized: waste recycling is the first cluster, followed by technology, the CE transformation, plastic waste, and waste management (WM). Examining WM and inclusive waste reduction practices and their distinct highlight patterns may impact future research fields and serve as a transitional tool to CE (which aims to minimize waste generation). Forthcoming research targets contain waste reduction and incorporation of WR into the CE framework.

Artificial Intelligence in Logistics Optimization with Sustainable Criteria: A Review

In recent years, the integration of artificial intelligence (AI) into logistics optimization has gained significant attention, particularly concerning sustainability criteria. This article provides an overview of the diverse AI models and algorithms employed in logistics optimization, with a focus on sustainable practices. The discussion covers several techniques, including generative models, machine learning methods, metaheuristic algorithms, and their synergistic combinations with traditional optimization and simulation methods. By employing AI capabilities, logistics stakeholders can enhance decision-making processes, optimize resource utilization, and minimize environmental impacts. Moreover, this paper identifies and analyzes prominent challenges within sustainable logistics, such as reducing carbon emissions, minimizing waste generation, and optimizing transportation routes while considering ecological factors. Furthermore, the paper explores emerging trends in AI-driven logistics optimization, such as the integration of real-time data analytics, blockchain technology, and autonomous systems, which hold immense potential for enhancing efficiency and sustainability. Finally, the paper outlines future research directions, emphasizing the need for further exploration of hybrid AI approaches, robust optimization frameworks, and scalable solutions that accommodate dynamic and uncertain logistics environments.

Validating Circular End-of-Life Strategies for Domestic Post-Consumer Materials in the Latin American Region: A Life Cycle Assessment Approach

This study examines the domestic solid waste management system in the LATAM region, using the city of Guayaquil in Ecuador as a case study. Through the life cycle assessment (LCA) methodology, the study compares domestic and external recycling processes, evaluating their effects on global warming potential, fossil resource scarcity, and terrestrial ecotoxicity. The results reveal that increasing recycling rates significantly reduces environmental impacts, with domestic recycling offering slightly higher environmental benefits than external options. A demographic analysis using machine learning techniques identifies distinct patterns of waste generation across different population clusters, highlighting the need for tailored waste management strategies. The study also emphasizes the importance of accurate local data and the integration of recycling initiatives with market realities, particularly in the light of policies mandating recycled content in products like PET bottles. A sensitivity analysis of the waste recovery indicator (WRI) demonstrates the potential for substantial environmental and economic benefits with higher recycling rates. The findings suggest that, to advance towards a circular economy, Latin American cities like Guayaquil must enhance their recycling infrastructure, refine waste management policies, and focus on demographic-specific strategies. This research contributes to the broader understanding of sustainable waste management in developing regions, offering insights for future policy and infrastructure development.

Evironmentally friendly comprehensive utilization of retired waste electrolytes of aluminum electrolysis by calcification leaching

Low energy consumption and environmentally friendly recycling methods can extract high-added value and high-demand elements from retired waste fluorinated aluminum electrolytes (RWE-Al), which is crucial for alleviating resource shortages and environmental hazards. This study aims to develop a method for recovering fluorine and aluminum from RWE-Al through calcium leaching transformation combined with acid leaching. Compared to the traditional high-temperature roasting transformation and high-concentration alkali-metal-salt leaching process, this new process only involves one step of low-temperature leaching, purification of fluorine, carbonization of excess calcium, and evaporation extraction of aluminum, avoiding the generation of high energy consumption and secondary hazardous waste (F-containing liquid/ residue). Fluorine and aluminum are effectively separated and purified with extraction rates exceeding 96%. The effects of leaching temperature, CaO addition coefficient, liquid–solid ratio, and leaching time on the leaching process were systematically studied. The effects of acid concentration, liquid–solid ratio, time, and temperature on the acid-leaching process were also investigated. In summary, the comprehensive utilization of RWE-Al by this new process has proved to be feasible.

Biochar-Supported Phytoremediation of Dredged Sediments Contaminated by HCH Isomers and Trace Elements Using Paulownia tomentosa

The remediation of dredged sediments (DS) as a major waste generation field has become an urgent environmental issue. In response to the limited strategies to restore DS, the current study aimed to investigate the suitability of Paulownia tomentosa (Thunb.) Steud as a tool for decontamination of DS, both independently and in combination with a sewage sludge-based biochar. The experimental design included unamended and biochar-supplemented DS with the application rates of 2.5, 5.0, and 10.0%, in which vegetation of P. tomentosa was monitored. The results confirmed that the incorporation of biochar enriched DS with the essential plant nutrients (P, Ca, and S), stimulated biomass yield and improved the plant’s photosynthetic performance by up to 3.36 and 80.0 times, respectively; the observed effects were correlated with the application rates. In addition, biochar enhanced the phytostabilisation of organic contaminants and shifted the primary accumulation of potentially toxic elements from the aboveground biomass to the roots. In spite of the inspiring results, further research has to concentrate on the investigation of the mechanisms of improvement the plant’s development depending on biochar’s properties and application rate and studying the biochar’s mitigation effects in the explored DS research system.

Pathways to a net zero building sector in Colombia: Insights from a circular economy perspective

The rapid urbanization and economic growth in Colombia have made the residential sector one of the largest energy and material consumers in the country. Circular economy (CE) strategies are a promising alternative to decouple the sector from resource depletion and climate change. The analysis shown here is based on the RECC model framework, a dynamic material flow analysis (dMFA) model. Our results suggest that by 2050 without CE strategies, residential building stock will reach 2.5 billion m2 and emit between 13 and 25 Mt CO2/yr, depending on whether carbon forest sequestration is included or not. A complete implementation of CE strategies and lower floor space can reduce 2020–2050 cumulative primary material production, waste generation, and GHG emissions by 48, 5, and 49 %, respectively. There is a potential to achieve net zero emissions by 2050 if, in addition to the measures mentioned above, more wood materials and forest sequestration are considered.

Sustainable Waste Management in Urban Area - A Case Study of the Waste Management of the Cities in China

As urbanisation continues to accelerate, the integration of regional waste treatment capacity is becoming increasingly important and challenging nowadays, as economic development imbalances and environmental problems are becoming more prominent. An important component of urban development is the generation and management of municipal solid waste , and due to differences in socio-economic status, China's world-class metropolises such as Shanghai and medium-sized cities such as Xiamen are facing the same problem. This study attempts to explore the possibilities and prospects for sustainable waste management in China's future by comparing Xiamen with Shanghai, using relevant structural models and relevant research data within the city and the region. The introduction of the concept of waste-free cities also provides a greater diversity of options for future programmes. Finding effective strategies based on China's socio-economic and cultural conditions has implications for developing countries such as China in promoting the shift from waste management to a circular economy.

Greening the city: A holistic assessment of waste management alternatives in India

Waste is one of the major urban challenges faced globally today, and the severity of the challenge is further exacerbated by rapid urbanisation, growing populations and increasing per capita waste generation. As one of the largest urban agglomerations in the world, Delhi collects 11,352 t of waste every day. Without adequate segregation, most of this waste is sent to dumpsites and waste-to-energy plants, often associated with significant capital costs and environmental externalities. This paper conducts a life cycle assessment of the current waste management system and a comparative analysis with a suggested alternative scenario, where the share of recyclables and compostables going to landfills and waste-to-energy plants is reduced through adequate segregation. Our results revealed that landfills and waste-to-energy plants are associated with significant adverse environmental impacts such as climate change, soil and water acidification, freshwater eutrophication, human toxicity, and respiratory health. In comparison, compost plants showed negligible emissions per tonne of waste. The alternative scenario (i.e. reduce waste to landfill through adequate segregation) can help reduce the negative impact on all environmental indicators by an average of 23 %. We posit that the prevailing narrative of addressing the waste issue through waste-to-energy plants in Delhi goes against the country's climate neutrality targets. Instead, the circular economy approach offers simpler, faster, and more cost-effective solutions that policymakers should consider to reduce the financial and environmental load of the current and future waste management issue.

Review of Waste Management in Indonesian Small Islands in the Last Five Years (2018-2023)

Indonesia is a maritime country composed of 16,771 islands consisting of large islands and small islands. One of the environmental problems that occur in small islands. Waste management is a shared focus because sources of water, soil and air pollution can come from waste. Waste management on small islands is very important because small islands have a much higher vulnerability than large islands.. This article aims to identify and analyze waste management in Indonesia's Small Islands and evaluate if its implementation has utilized the technology and concepts of the Industrial Revolution 4.0. Based on the findings of a review of 14 articles published from 2018-2023, with 15 islands as research objects, it was found that most of the small islands used as research objects had not managed their waste properly. The waste is eventually dumped into the sea. The unmanaged factor of this waste can be caused by the geographical conditions on the island which are bordered by the sea, the lack of waste management facilities, the limited land area on small islands and the low awareness and participation of the community in waste management. The rest, several islands have carried out the process of storage, processing, collection and destruction quite well. The waste is turned into handicrafts (bags and souvenirs), ecobricks, garden decorations and plant fertilizers for organic waste as well as the development of innovative waste into diesel fuel. Unfortunately, the intended application based on the Industrial Revolution 4.0 has not been reflected in waste management on these small islands. This is expected to be information and input for the government and managers as a model for other small islands in an effort to manage waste generation on the island's mainland and garbage contamination in the sea.

The Decontamination of N95 Masks as an Occupational Safety Strategy

Objective: This study aimed to monitor the use of a short-wave ultraviolet (UV-C) decontamination device for N95 masks at the João de Barros Barreto University Hospital, Belém, Pará, Brazil. The research investigated the reuse of masks, storage methods, and the perception of healthcare professionals regarding the decontamination protocol using UV-C after each work shift. Theoretical Framework: The research is based on theories related to biosafety and occupational health, focusing on the importance of decontamination processes in hospital settings to enhance the protection of healthcare workers and reduce infection risks. Method: A cross-sectional study was conducted with 295 nursing professionals, including nurses, technicians, and assistants. Data were collected through a questionnaire addressing the reuse of N95 masks, storage between uses, and opinions on the use of the UV-C device for decontamination. Results and Discussion: All participants (n=295) agreed that UV-C decontamination improves biosafety by reducing the handling of potentially contaminated masks. The acceptance of the device was unanimous, confirming its feasibility both in high-demand scenarios, such as the Covid-19 pandemic, and in routine hospital practices. Research Implications: This study demonstrates that implementing UV-C decontamination systems is a practical and effective solution for hospitals, with the potential to increase occupational safety and reduce infectious waste generation. Originality/Value: The study contributes to the literature by highlighting the feasibility and benefits of reusing N95 masks with UV-C decontamination, promoting greater safety in hospital environments.

Circular–Sustainable–Reliable Waste Management System Design: A Possibilistic Multi-Objective Mixed-Integer Linear Programming Model

Waste management involves the systematic collection, transportation, processing, and treatment of waste materials generated by human activities. It entails a variety of strategies and technologies to diminish environmental impacts, protect public health, and conserve resources. Consequently, providing an effective and comprehensive optimization approach plays a critical role in minimizing waste generation, maximizing recycling and reuse, and safely disposing of waste. This work develops a novel Possibilistic Multi-Objective Mixed-Integer Linear Programming (PMOMILP) model in order to formulate the problem and design a circular–sustainable–reliable waste management network, under uncertainty. The possibility of recycling and recovery are considered across incineration and disposal processes to address the main circular-economy principles. The objectives are to address sustainable development throughout minimizing the total cost, minimizing the environmental impact, and maximizing the reliability of the Waste Management System (WMS). The Lp-metric technique is then implemented into the model to tackle the multi-objectiveness. Several benchmarks are adapted from the literature in order to validate the efficacy of the proposed methodology, and are treated by CPLEX solver/GAMS software in less than 174.70 s, on average. Moreover, a set of sensitivity analyses is performed to appraise different scenarios and explore utilitarian managerial implications and decision aids. It is demonstrated that the configured WMS network is highly sensitive to the specific time period wherein the WMS does not fail.

Sustainable Strategies for Responsible Fashion: Adopting the Reduce, Reuse and Recycle Practices

The fashion sector, which contributes approximately 10% to global carbon emissions, exerts a considerable influence on the environment. The rapid pace of fast fashion has intensified both waste generation and resource utilization, thereby rendering sustainable practices an essential requirement. This study examines sustainable methodologies within the fashion industry, with particular emphasis on the implementation of the Reduce, Reuse, and Recycle (RRR) framework. The article explores how global and local brands in Delhi incorporate such strategies into their operations and gauges consumer awareness and behavior towards sustainable fashion. Studies indicate that barriers faced by brands while trying to achieve sustainability include the high price tag of sustainable materials, minimal recycling facilities, and the price sensitivity of the consumer. Hypothesis testing was used to examine whether the consumer behavior was significant on their purchasing decisions and sustainability. The results reflected that, while there is indeed a growth in awareness, consumers' intentions and actual purchasing behaviors seem to be quite divergent concerning the acceptance of sustainable fashion. Furthermore, the paper makes workable recommendations to make the fashion industry more sustainable by focusing on policy measures, innovations in brands, and education for the consumer. Key Words: sustainable fashion, reduce reuse recycle, consumer behavior, competitive advantage, supply chain sustainability

First step to environmentally sustainable endoscopy practice: Prospective study of minimizing multiple device use during screening colonoscopy at a large tertiary center.

The healthcare sector generates 8% of greenhouse emissions in the United States, of which GI endoscopy is the third largest contributor. Single-use tools are a major contributor to modifiable waste generation during GI (gastrointestinal) endoscopy. Through a quality improvement (QI) initiative, we aimed to reduce endoscopy waste by urging gastroenterologists to be mindful of the tools used during polypectomies and avoid using multiple tools. We discussed green endoscopy initiatives in monthly journal club and business meetings. Over 14 weeks, 210 patients were included in the pre-intervention and 112 in the post-intervention group. At baseline, 34% of colonoscopies required no intervention, 32% required one tool (either biopsy forceps or a snare) and 33% required multiple tools. After the intervention, the use of just one tool increased (17% increase, p<0.01) and the use of multiple tools decreased significantly (16% decrease p<0.01). The odds of using a single tool compared to multiple tools after the intervention was 2.98 (95% CI 1.6-5.53), p=0.005. This single-center QI study noted a significant change in practice patterns favoring using a single tool over multiple tools during colonoscopies after an environmentally conscious practice intervention was applied. This intervention can be readily applied to reduce endoscopy-related waste.

Going circular with what we wear and how we build: parallelisms between the Dutch and French catwalks of fashion and construction

Responding to the call for circular transition, the Dutch and French governments aspire to achieve a fully circular economy by developing a transitional agenda in various sectors, including fashion and construction. The two countries are among the top 10 waste generators in the European Union (EU), while the two sectors—fashion and construction—are the largest polluters in the EU. The aim of this study, and its main contribution, is to harmonize circular design principles, which vary by sector into common types, and identify the circular design principle that balances the sustainability dimensions the most. This responds to research gaps that merely describe these design principles applicable to different sectors but which are also silent on which achieves sustainability balance. Using multicriteria decision analysis, selected case studies of companies in the two sectors and countries were scored and ranked according to environmental, economic, and social sustainability indicators. The case projects were selected based on the circular design principle that the enterprises were applying. These principles were standardized for the two sectors to come up with five distinct types, namely, design for (i) biobased materials, (ii) service/adaptability, (iii) disassembly, (iv) waste and material recovery, and (v) longevity. Three forms of triangulation were used to achieve reliability, validity, and equivalence of the findings: (i) data—by doubling the size of the sample cases to 40 establishments from 20, (ii) investigator—by having the authors score the projects separately, and (iii) method—by using two objective weighting methods in scoring the criteria. These techniques resulted in similar rankings of the cases in terms of triple bottom-line scores per design principle. Designing for biobased materials turned out to achieve the most balance. The case projects were also compared regarding performance in achieving the UN Sustainability Development Goals (SDGs), which companies use to integrate sustainability with business. Circularity in fashion and construction primarily targets responsible consumption, production, and climate action. A tertiary SDG was life on water and access to clean water for fashion and life on land and sustainable cities for construction.

Microplastic levels in the indoor air of buildings based on plastic waste recycling in Indonesia

Introduction: Microplastics are a new type of contamination in the environment caused by plastic fragmentation and degradation. The generation of plastic waste increases every year, therefore efforts are made to recycle it into building materials. It is unclear how building use resulting from recycling plastic waste affects the development of microplastics in the atmosphere. The purpose of this study is to determine the airborne concentrations of microplastics in buildings constructed from recycled plastic waste. Materials and methods: The study measured microplastic levels in the air for 30 days in a miniature building made from plastic waste. Samples taken during the dry season in Indonesia in 2023. Air sampling is carried out by passive method. Visual observation of the shape, and amount of microplastics using a microscope. Results: Microplastics are found in the air of building spaces made from recycled plastic waste with varying levels every day. The average level of microplasty in the air for 30 days was 30,8 particles/m2/day. Maximum microplastic rate of 63 particles/m2/day, and minimum rate of 18 particles/m2/ day. The average air temperature when sampling is 25,48 ºC, air humidity is 68,37 % and ultraviolet intensity is 860 mwatt/cm2. Conclusions: Microplastic levels in the air of building spaces made from recycled plastic waste that can not be identified can be identified whether they are still within safe limits or not. This is because there is no regulation in Indonesia even in the world that regulates the safe limit of microplastic levels in the environment.

Synthesis of Isoxazol-5-One Derivatives Catalyzed by Amine-Functionalized Cellulose

In this contribution, propylamine-functionalized cellulose (Cell-Pr-NH2) was employed as the catalyst in the three-component reaction between hydroxylamine hydrochloride and various types of aryl/heteroaryl aldehydes, ethyl acetoacetate/ethyl 4-chloroacetoacetate, or ethyl 3-oxohexanoate. The result of these experiments was the formation of 3,4-disubstituted isoxazol-5(4H)-one heterocycles. The desired five-membered heterocyclic compounds were obtained in good to high yields at room temperature. The investigation of different solvents led us to the conclusion that water is the best solvent to perform the current one-pot, three-component reactions. Attempts to find the optimal catalyst loading clearly showed that 14 mg of cell-Pr-NH2 seems to be sufficient to carry out the reactions. This method has highlighted some principles of green chemistry including less waste generation, atom economy, use of water as an environmentally friendly solvent, and energy saving. Purification without chromatographic methods, mild reaction conditions, simple work-up, low-cost reaction medium, saving time, and obtainable precursors are other notable features of this one-pot fashion.

Poultry slaughterhouse waste management through anaerobic digestion with varying proportions of chicken litter

Nepal's burgeoning poultry industry which is a key sector in its economy leads to a considerable generation of slaughterhouse waste (SHW), necessitating effective and sustainable disposal methods. This study explores anaerobic digestion as an optimal solution for poultry SHW management, aiming to produce energy-rich biogas while efficiently mitigating pollution in these facilities. Particularly, the feasibility and effectiveness of co-digestion with chicken litter (CL) were investigated to enhance biogas production and waste utilization. Four distinct runs of anaerobic digestion were performed, each utilizing varying substrate compositions with SHW to CL ratios of 1:0, 4:1, 1:1, and 1:4. Throughout the process, essential parameters, including total solids (TS), volatile solids (VS), biological oxygen demand (BOD5), pH, temperature, biogas generation, were meticulously measured. The cumulative biogas production for each run was as follows: 14.87 liters and a biogas yield of 88.73 ml/gVS with a 17.39 % VS reduction for Run 1, 25.98 liters and a biogas yield of 147.21 ml/gVS with a 28.64 % VS reduction for Run 2, 78.32 liters and a biogas yield of 314.69 ml/gVS with a 54.32 % VS reduction for Run 3, and 89.195 liters and a biogas yield of 344.36 ml/gVS with a 63.05 % VS reduction for Run 4. Notably, as the proportion of CL increased in the mixture from 4:1 to 1:1, a considerable VS reduction was observed. Furthermore, when the ratio of SHW to CL reached 1:1 and 1:4, a significant BOD5 reduction of 50 % and 63.13 % was achieved, respectively, surpassing previous runs. The results reveal that the addition of CL in an appropriate ratio effectively manages poultry SHW, with the optimum SHW:CL ratio for significant biogas yield lying between 1:1 and 1:4.

Challenges in the Valorization of Green Waste in the Central European Region: Case Study of Warsaw

Expanding green areas in cities results in growth in green waste generation. This study presents the findings of an investigation into green waste from selective collection in a large Central European city (Warsaw, Poland), which can be identified as a valuable biomass resource. The research objective was to identify the properties of garden waste from single-family housing to determine valorization opportunities, emphasizing the utilization of GW as a source of energy. The research yielded several findings, including a notable degree of variability in fuel properties, including moisture content (CV = 30%), lower heating value (CV = 14.3%), and ash content (CV = 62.7/56.2%). The moisture content suggests composting, while the fertilizing properties indicate suitability for anaerobic digestion. The instability of the fuel properties, coupled with the elevated levels of chlorine, sulfur, and moisture, constrains the use of garden waste in thermal processes and alternative fuel production. Pyrolysis could be a viable approach for green waste feedstock, offering value-added products depending on the processing conditions and pre-treatment. Nevertheless, implementing a selective collection system is a critical condition for the optimal utilization of bio-waste, facilitating the quality and property control of green and food waste. This is essential for their effective processing, including energy recovery, thereby contributing to the efficient valorization of biomass.

Evaluating the mechanical and environmental impact of PEF plastic waste incorporated with graphene nano-platelets in concrete

There has been a significant surge in the yearly use of plastics, leading to a notable rise in plastic waste generation. Consequently, the recycling of plastic garbage has emerged as a prominent concern around the world. This research explores the feasibility of using polyethylene furanoate (PEF) plastic waste as a substitute for coarse aggregate (CA) in concrete. Graphene nano-platelets (GNPs) were added to the concrete mix in different quantities to improve its structural reliability. The research study used an experimental research design in conducting its investigation. PEF waste plastic was added in concrete in varying proportions of 0%, 5%, 15%, 20%, and 25% as a supplementary material to gravel, and GNPs were added in different percentages of 0%, 0.03%, 0.05%, 0.08%, and 0.1% by weight of cement. Mechanical tests were conducted, which includes compressive strength (CS), split tensile strength (STS), flexural strength (FS), modulus of elasticity (MoE), and ultrasonic pulse velocity (UPV), and the environmental assessment of concrete was done by assessing carbon in concrete and concrete’s eco efficiency (ESE). It was found that 5% addition of PEF as the substitute to CA and 0.1% of GNPs gives the optimum strength, enhancing CS, STS, and FS by 9.10%, 18.18%, and 4.45%, respectively. Response surface technique (RSM) models were created to provide mathematical equations for predicting the predicted outcomes. All models were optimized using a multi-objective optimization approach and then validated.

A novel design optimization framework to sustain remanufacturability

The ever-increasing global carbon emissions have urged the need for environmentally conscious/sustainable product design, for which the design for remanufacturing (DfRem) is one potential approach. DfRem targets at designing products that have multiple life cycles, thus significantly reducing raw material usage, energy consumption, and carbon emissions. In this paper, we develop a three-stage framework that consists of (1) systematic design space exploration and a multi-objective optimization formulation to minimize the likelihood of failure causes (such as fatigue and wear) and environmental footprint, (2) topology optimization to further reduce material usage without significantly affecting the load-carrying capability of the product, and (3) post-topology optimization design verification to ensure the proposed design satisfies all design constraints. The environmental impact can be assessed at varying comprehensiveness levels (e.g., design and manufacturing phase, use phase) and in terms of carbon or GHG emission, energy use, and waste generation. Because the novel design framework predominantly adjusted the geometry, we focused on mass-based change and energy savings due to sustained remanufacturability. The multi-objective optimization formulation in the first step results in a Pareto optimal set of possible design solutions that the designer can use for the second step. We demonstrate the utility of this framework through a case study of an engine cylinder head subjected to thermo-mechanical loads, where we find that about 5% of the product mass can be conserved with only about a 3% increase in surface area that has a fatigue life less than 10,000 cycles.