An evaluation model for city-scale construction and demolition waste management effectiveness: A case study in China.

The growing generation of construction and demolition waste (CDW) has emerged as a prominent challenge on global environmental agendas. However, the effectiveness of CDW management (CDWM) strategies varies among cities. Existing literature predominantly evaluates the effectiveness of CDWM at the project level, offering a localized perspective that fails to capture a city's comprehensive CDWM profile. This localized focus has certain limitations. To fill this gap in city-scale evaluations, this study introduces a novel model for assessing CDWM effectiveness at the municipal level. An empirical investigation was conducted across 11 cities within the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) to operationalize this model. The model defines five distinct levels of CDWM effectiveness. Findings indicate that Hong Kong consistently achieves the highest level (level I), while the majority of cities fall within levels III and IV. This pattern suggests that CDWM effectiveness in the GBA is moderately developed, with uneven progress in CDW management outcomes and supporting systems. Essentially, there is a lack of synchronous development of CDWM results and guarantee systems. The proposed evaluation model enriches existing CDWM research field and offers a framework that may inform future studies in other countries.

Integrating fuzzy-AHP and GIS for solid waste disposal site selection in Kenitra province, NW Morocco.

Selecting an optimal solid waste disposal site is one of the decisive waste management issues because unsuitable sites cause serious environmental and public health problems. In Kenitra province, northwest Morocco, sustainable disposal sites have become a major challenge due to rapid urbanization and population growth. In addition, the existing disposal sites are traditional and inappropriate. The objective of this study is to suggest potential suitable disposal sites using fuzzy logic and analytical hierarchy process (fuzzy-AHP) method integrated with geographic information system (GIS) techniques. For this purpose, thirteen factors affecting the selection process were involved. The results showed that 5% of the studied area is considered extremely suitable and scattered in the central-eastern parts, while 9% is considered almost unsuitable and distributed in the northern and southern parts. Thereafter, these results were validated using the area under the curve (AUC) of the receiver operating characteristics (ROC). The AUC found was 57.1%, which is a moderate prediction's accuracy because the existing sites used in the validation's process were randomly selected. These results can assist relevant authorities and stakeholders for setting new solid waste disposal sites in Kenitra province.

Effective food waste management model for the sustainable agricultural food supply chain.

The extensive research examines the current state of agricultural food supply chains, with focus on waste management in Bandung Regency, Indonesia. The study reveals that a significant proportion of food within the agricultural supply chain goes to waste and discusses the various challenges and complexities involved in managing food waste. The research presents a conceptual model based on the ADKAR change management paradigm to promote waste utilization, increase awareness and change people's behaviors. The model emphasizes the importance of creating awareness, fostering desire, providing knowledge, implementing changes, and reinforcing and monitoring the transformation process. It also addresses the challenges, barriers, and drivers that influence waste utilization in the agricultural supply chain, highlighting the need for economic incentives and a shift in public awareness to drive meaningful change. Ultimately, this study serves as a comprehensive exploration of food waste management in Bandung Regency, shedding light on the complexities of the issue and offering a systematic approach to transition towards more sustainable waste utilization practices.

Evaluating factors promoting waste scavenging and its implications in a growing urban environ in Nigeria.

Despite the inherent risks associated with waste scavenging, it is surprising to note the age group involved in this activity. This study aimed to assess the motivating factors driving teenagers and youths to participate in waste scavenging, using a sample of 247 scavengers. The data underwent analysis using frequency counts, percentages, and factor analysis techniques. The findings revealed that all respondents were male and aged between 12 and 45 years. The primary sources of waste were dumpsites (61%), roadsides, and gutters (26%). Participants predominantly cited lack of formal education requirements and financial gain (93%) as key motivators for their involvement in waste scavenging. Additionally, 96% of scavengers were from northern Nigeria, with the remaining 4% from southern Nigeria. The factor analysis yielded significant results with a Kaiser-Meyer-Olkin (KMO) measure and Bartlett's test value of 67.770%, significant at p < 0.05. Four distinct factors emerged as significant motivators: (i) Lack of formal education (31.784%), (ii) Financial incentives (22.912%), (iii) Availability of wastes (14.297%), and (iv) Industrial demand for wastes (13.495%), in descending order of influence. Together, these factors accounted for 82.487% of the motivating factors behind youth engagement in waste scavenging in the study area. This outcome highlights potential challenges for the prospects of young individuals involved in scavenging unless substantial interventions are implemented. It is recommended that policies be developed to discourage scavenging activities while simultaneously promoting access to education and social welfare for this demographic. Such initiatives are crucial for redirecting young people away from scavenging and toward more sustainable livelihood options, ensuring a brighter future for them and contributing to overall societal development.

Implementation of sustainable food service systems in hospitals to achieve current sustainability goals: A scoping review.

BACKGROUND: Food waste is a pivotal contributor to environmental degradation in the modern world. Vast amounts of food are wasted and many individual efforts and collective initiatives being underway to deal with this challenge. Hospitals are institutions that produce and provide food, but at the same time contribute greatly to food waste. The objective of this scoping review is to present available data regarding quantity of food waste generated in public hospitals and summarizes studies that assess and quantify the greenhouse gas emissions (carbon footprint) associated to food service management in hospitals. METHODS: A systematic literature research was conducted by two qualified researchers in PubMed, Scopus, ISI Web of Science and Science Direct. The publication date was set to the last ten years, i.e., 2013-2023. All the abstracts retrieved were screened, and the eligible articles were selected after a two-step process. Abstracts from the retrieved full papers' references were also screened for eligibility. The selected papers were included in the final scoping review. RESULTS: Overall, 2870 studies were identified and 69 were included in the review. Most of the studies (n = 33) assessed the causes and quantified the amount of food waste generated in hospitals. A small number of studies (5) estimated carbon dioxide equivalent (CO2-eq) produced by food waste. Although several studies suggested strategies and measures to reduce the environmental impact of foodservice operations, none of them implemented a comprehensive foodservice management system. CONCLUSION: This scoping review suggests that hospital diets contribute to food waste and may have a negative environmental impact. There are several internal and external factors and practices that influence positively or negatively the sustainability of hospital food service systems. Systematic efforts are needed to identify and enhance parameters that could improve the environmental footprint of hospitals in terms of more effective management of food waste.

Forecasting municipal solid plastic waste generation and management policy using system dynamics: a case study of Khulna City in Bangladesh.

A comprehensive analysis of municipal solid plastic waste (MSPW) management while emphasizing plastic pollution severity in coastal cities around the world is mandatory to alleviate the augmenting plastic waste footprint in nature. Thus, decision-makers' persuasion for numerous management solutions of MSPW flow-control can be met through meditative systematic strategies at the regional level. To forecast solutions focused on systematic policies, an agent-based system dynamics (ASD) model has been developed and simulated from 2023 to 2040 while considering significant knit parameters for MSPW management of Khulna City in Bangladesh. Baseline simulation results show that per-capita plastic waste generation will increase to 11.6 kg by 2040 from 8.92 kg in 2023. Eventually, the landfilled quantity of plastic waste has accumulated to 70,000 tons within 18 years. Moreover, the riverine discharge has increased to 834 tons in 2040 from a baseline quantity of 512 tons in 2023. So the plastic waste footprint index (PWFI) value rises to 24 by 2040. Furthermore, the absence of technological initiatives is responsible for the logarithmic rise of non-recyclable plastic waste to 1.35*1000=1350 tons. Finally, two consecutive policy scenarios with baseline factors such as controlled riverine discharge, increased collection and separation of plastic waste, expansion of recycle business, and locally achievable plastic conversion technologies have been simulated. Therefore, policy 2, with 69% conversion, 80% source separation, and 50% riverine discharge reduction of MSPW, has been found adequate from a sustainability perspective with the lowest PWFI ranges of 3.97 to 1.07 alongside a per-capita MSPW generation of 7.63 to 10 kg from 2023 till 2040.

Agricultural Waste Management by Production of Second-Generation Bioethanol from Sugarcane Bagasse Using Indigenous Yeast Strain.

In the wake of rapid industrialization and burgeoning transportation networks, the escalating demand for fossil fuels has accelerated the depletion of finite energy reservoirs, necessitating urgent exploration of sustainable alternatives. To address this, current research is focusing on renewable fuels like second-generation bioethanol from agricultural waste such as sugarcane bagasse. This approach not only circumvents the contentious issue of food-fuel conflicts associated with biofuels but also tackles agricultural waste management. In the present study indigenous yeast strain, Clavispora lusitaniae QG1 (MN592676), was isolated from rotten grapes to ferment xylose sugars present in the hemicellulose content of sugarcane bagasse. To liberate the xylose sugars, dilute acid pretreatment was performed. The highest reducing sugars yield was 1.2% obtained at a temperature of 121 °C for 15 min, a solid-to-liquid ratio of 1:25 (% w/v), and an acid concentration of 1% dilute acid H2SO4 that was significantly higher (P < 0.001) yield obtained under similar conditions at 100 °C for 1 h. The isolated strain was statistically optimized for fermentation process by Plackett-Burman design to achieve the highest ethanol yield. Liberated xylose sugars were completely utilized by Clavispora lusitaniae QG1 (MN592676) and gave 100% ethanol yield. This study optimizes both fermentation process and pretreatment of sugarcane bagasse to maximize bioethanol yield and demonstrates the ability of isolated strain to effectively utilize xylose as a carbon source. The desirable characteristics depicted by strain Clavispora lusitaniae shows its promising utilization in management of industrial waste like sugarcane bagasse by its conversion into renewable biofuels like bioethanol.

Plastic Pandemic after COVID-19: A Global Health Concern.

Abstract: COVID-19 pandemic has increased the amount of plastic burden to environment and complexities of plastic waste management. Change in behavioral pattern with advent of this pandemic led to increased practice of hygiene and increased use of different types of personal protective equipment. Unfortunately, rapid rise in production of the PPEs (like Hazmat suit, gloves, etc.) and single-use plastics used in RT-PCR and other testing are the biggest source for increased non-biodegradable plastic waste leading to amplified burden on plastic waste management. A number of measures like prioritizing the policies directed towards changes at behavioral, social and institutional level need to be started. Also, reduction in plastic waste along with proper plastic waste management policies should be implemented. To prevent the transition from one pandemic to other; improvement in government policies with public private partnership are the need of the hour.

Waste to resource recovery at a marina: Empirical evidence of upstream and downstream innovation for circularity.

In 2021, an Australian research centre partnered with a regional marina and shipyard where 90 businesses build, refit, and maintain boats in premium condition. Tenants and owners grapple with environmental waste management issues. Since there is a gap in applying action research but numerous calls to co-produce solutions and participate in translating ideas into practice, action research was used in this case study involving upstream and downstream innovation for circularity. Mixed methods data was collected through interviews, stakeholder workshops, and waste audits. A strategic action plan was created for closing the loop on waste. Interventions included tackling toxic, degradable products with natural alternatives, trading and remanufacturing materials to extend product life cycles, testing problematic materials, and pursuing product stewardship. This study is novel because it extends diffusion of innovation theory to real-world impact through a co-innovation process. Results underscore that ongoing achievements depend on properly sorting waste, accessing reprocessing facilities, and maintaining dedicated staff and partnerships, especially legislative support for making continuous improvement.

Plastic waste management through liquefaction in hydrogen donating solvents: A review.

Plastic pollution poses a significant environmental threat, particularly to marine ecosystems, as conventional plastics persist without degradation, accumulating plastic waste in landfills and natural environments. A promising alternative to address this issue involves the use of hydrogen donor solvents in plastic liquefaction, offering a dual benefit of waste reduction and the generation of valuable liquid products with diverse industrial applications. This review delves into plastic recycling methods with a specific focus on liquefaction using hydrogen donating solvents as an innovative approach to waste management. Liquefaction, conducted at moderate to high temperatures (280-450 °C) and pressures (7-30 MPa), yields high oil conversion using various solvents. This study examined the performance of hydrogen-donating solvents, including water, alcohols, decalin, and cyclohexane, in enhancing the oil yield while minimising the oxygen content. Supercritical water, recognised for its effective plastic degradation and chemical production capabilities, and alcohols, with their alkylating and hydrogen-donating properties, have emerged as key solvents in plastic liquefaction. The use of hydrogen donor solvents stabilizes the free radicals, enhancing the conversion of plastic waste into valuable products. In addition, this review addresses the economic efficiency of the liquefaction process.

Correlations and impact of anaerobic digestion operating parameters on the start-up duration: Database construction for robust start-up guidelines.

Anaerobic digestion (AD) has become a popular technique for organic waste management while offering economic and environmental advantages. As AD becomes increasingly prevalent worldwide, research efforts are primarily focused on optimizing its processes. During the operation of AD systems, the occurrence of unstable events is inevitable. So far, numerous conclusions have been drawn from full and lab-scale studies regarding the driving factors of start-up perturbations. However, the lack of standardized practices reported in start-up studies raises concerns about the comparability and reliability of obtained data. This study aims to develop a knowledge database and investigate the possibility of applying machine learning techniques on experimentation-extracted data to assist start-up planning and monitoring. Thus, a standardized database referencing 75 cases of start-up of one-stage wet continuously-stirred tank reactors (CSTR) processing agricultural, industrial, or municipal organic effluent in mono-digestion from 31 studies was constructed. 10 % of the total observations included in this database concern failed start-up experiments. Then, correlations between the parameters and their impacts on the start-up duration were studied using multivariate analysis and a model-based ranking methodology. Insights into trends of choices were highlighted through the correlation analysis of the database. As such, scenarios favoring short start-up duration were found to involve relatively low retention times (average initial and final hydraulic retention times, (HRTi) and (HRTf) of 26.25 and 20.6 days, respectively), high mean organic loading rates (average OLRmean of 5.24 g VS·d-1·L -1) and the processing of highly fermentable substrates (average feed volatile solids (VSfeed) of 81.35 g L-1). The model-based ranking of AD parameters demonstrated that the HRTf, the VSfeed, and the target temperature (Tf) have the strongest impact on the start-up duration, receiving the highest relative scores among the evaluated AD parameters. The database could serve as a reference for comparison purposes of future start-up studies allowing the identification of factors that should be closely controlled.

Utilization of plant-derived wastes as the potential biohydrogen source: a sustainable strategy for waste management.

The sustainable economy has shown a renewed interest in acquiring access to the resources required to promote innovative practices that favor recycling and the reuse of existing, unconsidered things over newly produced ones. The production of biohydrogen through dark anaerobic fermentation of organic wastes is one of the intriguing possibilities for replacing fossil-based fuels through the circular economy. At present, plant-derived waste from the agro-based industry is the main global concern. When these wastes are improperly disposed of in landfills, they become the habitat for several pathogens. Additionally, it contaminates surface water as a result of runoff, and the leachate that is created from the waste enters groundwater and degrades its quality. However, cellulose and hemicellulose-rich plant wastes from agriculture fields and agro-based industries have been employed as the most efficient feedstock since carbohydrates are the primary substrate for the synthesis of biohydrogen. To produce biohydrogen from plant-derived wastes on a large scale, it is necessary to explore comprehensive knowledge of lab-scale parameters and pretreatment strategies. This paper summarizes the problems associated with the improper management of plant-derived wastes and discusses the recent developments in dark fermentation and substrate pretreatment techniques with the goal of gaining significant insight into the biohydrogen production process. It also highlights the utilization of anaerobic digestate, which is left over after biohydrogen gas as feedstock for the development of value-added products such as volatile fatty acids (VFA), biochar, and biofertilizer.

Agro-industrial waste management employing benefits of artificial intelligence.

By 2050, the world's population is predicted to reach over 9 billion, which requires 70% increased production in agriculture and food industries to meet demand. This presents a significant challenge for the agri-food sector in all aspects. Agro-industrial wastes are rich in bioactive substances and other medicinal properties. They can be used as a different source for manufacturing products like biogas, biofuels, mushrooms, and tempeh, the primary ingredients in various studies and businesses. Increased importance is placed on resource recovery, recycling, and reusing (RRR) any waste using advanced technology like IoT and artificial intelligence. AI algorithms offer alternate, creative methods for managing agro-industrial waste management (AIWM). There are contradictions and a need to understand how AI technologies work regarding their application to AIWM. This research studies the application of AI-based technology for the various areas of AIWM. The current work aims to discover AI-based models for forecasting the generation and recycling of AIWM waste. Research shows that agro-industrial waste generation has increased worldwide. Infrastructure needs to be upgraded and improved by adapting AI technology to maintain a balance between socioeconomic structures. The study focused on AI's social and economic impacts and the benefits, challenges, and future work in AIWM. The present research will increase recycling and reproduction with a balance of cost, efficiency, and human resources consumption in agro-industrial waste management.

Revitalizing plastic wastes employing bio-circular-green economy principles for carbon neutrality.

The use of plastics has become deeply ingrained in our society, and there are no indications that its prevalence will decrease in the foreseeable future. This article provides a comprehensive overview of the global plastic waste disposal landscape, examining it through regional perspectives, various management technologies (dumping or landfilling, incineration, and reuse and recycling), and across different sectors including agriculture and food, textile, tourism, and healthcare. Notably, this study compiles the findings on life-cycle carbon footprints associated with various plastic waste management practices as documented in the literature. Employing the bio-circular-green economy model, we advocate for the adoption of streamlined and sustainable approaches to plastic management. Unique management measures are also discussed including the utilization of bioplastics combined with smart and efficient collection processes that facilitate recycling, industrial composting, or anaerobic digestion. Moreover, the integration of advanced recycling methods for conventional plastics with renewable energy, the establishment of plastic tax and credits, and the establishment of extended producer responsibility are reviewed. The success of these initiatives relies on collaboration and support from peers, industries, and consumers, ultimately contributing to informed decision-making and fostering sustainable practices in plastic waste management.

A review on the enhancement of circular economy aspects focusing on nanocellulose composites.

Researchers are now focusing on using the circular economy model to manufacture nanocellulose composites due to growing environmental issues related to waste management. The circular economy model offers a sustainable solution to the problem by optimizing resource efficiency and waste management by reducing waste, maintaining value over time, minimizing the use of primary resources, and creating closed loops for goods, components, and materials. With the use of the circular economy model, waste, such as industrial, agricultural, and textile waste, is used again to produce new products, which can solve waste management issues and improve resource efficiency. In order to encourage the use of circular economy ideas with a specific focus on nanocellulose composites, this review examines the concept of using circular economy, and explores ways to make nanocellulose composites from different types of waste, such as industrial, agricultural, and textile waste. Furthermore, this review investigates the application of nanocellulose composites across multiple industries. In addition, this review provides researchers useful insights of how circular economics can be applied to the development of nanocellulose composites, which have the goal of creating a flexible and environmentally friendly material that can address waste management issues and optimize resource efficiency.

The potential impact of the new 'Right to Repair' rules on electrical and electronic equipment waste: A case study of the UK.

Every year an estimated two million tonnes of waste electrical and electronic equipment (WEEE) are discarded by householders and companies in the United Kingdom (UK). While the UK has left the European Union (EU), its waste-related policies still mirror those of the EU, including the WEEE-related policies. Motivated by the recent introduction the so-called 'Right to Repair' policy for electrical and electronic equipment (EEE) across the EU and UK, this paper aims to demonstrate that, depending on the commitment and behavioural changes by the consumers and the government, the future of the WEEE management of the UK will vary. To this end, focusing on landfilled WEEE reduction we develop a generic system dynamics model and apply it to eleven WEEE categories. They depict the flow of EEE and WEEE representing the interaction among the stakeholders (e.g., consumers and producers of EEE) and relevant government regulations of the UK. Our four scenario analyses find that longer use of EEE and better WEEE collection seem to be effective in reducing landfilled WEEE, while more reuse and more recycling and recovery have negligible impacts, despite excluding the additional generation of landfilled WEEE as a result of recycling and recovery. Comparing with the business-as-usual scenario, one year longer EEE use and 10% more of WEEE collection could at maximum reduce landfilled WEEE by 14.05% of monitoring and control instruments and 93.93% of display equipment respectively. Backcasting scenario analyses reveal that significant efforts are required to reduce the targeted amounts.

Co-processing of end-of-life wind turbine blades in portland cement production.

The objective of this paper is to evaluate the feasibility of co-processing wind turbine blade (WTB) material in cement manufacturing to provide an end-of-life means to divert the solid waste of decommissioned WTBs from landfills. Many WTBs consist primarily of glass fiber reinforced thermoset polymers that are difficult to recover or recycle. Portland cement is produced world-wide in large quantities, requiring immense quantities of raw materials (mostly calcium oxide and silicon oxide) and kiln temperatures approaching 1,450 °C. This work contributes analyses of WTB material composition, and predicts the energy provided through the combustible components of the WTBs and raw material contributions provided by incorporating the incombustible components of the WTBs to produce cement. Approximately 40 to 50 % of the WTB material will contribute as fuel to cement production, and approximately 50 to 60 % of the WTB material is expected to be incombustible. One tonne of WTB material can displace approximately 0.4 to 0.5 tonne of coal, while also contributing approximately 0.1 tonne of calcium oxide and 0.3 tonne of silicon oxide as raw material to the cement production process. The glass fiber WTB tested had an average boron content of 4.5 % in the ash. The effects of this high boron content on the cement and its production process should be evaluated. Co-processing WTBs in cement plants will slightly reduce combustion-related CO2 emissions due to avoided calcination. It seems feasible to co-process glass-fiber reinforced WTBs in cement production as WTBs provide suitable raw materials and compatible fuel for this process.

Intelligent and sustainable waste classification model based on multi-objective beluga whale optimization and deep learning.

Resource recycling is considered necessary for sustainable development, especially in smart cities where increased urbanization and the variety of waste generated require the development of automated waste management models. The development of smart technology offers a possible alternative to traditional waste management techniques that are proving insufficient to reduce the harmful effects of trash on the environment. This paper proposes an intelligent waste classification model to enhance the classification of waste materials, focusing on the critical aspect of waste classification. The proposed model leverages the InceptionV3 deep learning architecture, augmented by multi-objective beluga whale optimization (MBWO) for hyperparameter optimization. In MBWO, sensitivity and specificity evaluation criteria are integrated linearly as the objective function to find the optimal values of the dropout period, learning rate, and batch size. A benchmark dataset, namely TrashNet is adopted to verify the proposed model's performance. By strategically integrating MBWO, the model achieves a considerable increase in accuracy and efficiency in identifying waste materials, contributing to more effective waste management strategies while encouraging sustainable waste management practices. The proposed intelligent waste classification model outperformed the state-of-the-art models with an accuracy of 97.75%, specificity of 99.55%, F1-score of 97.58%, and sensitivity of 98.88%.

Life cycle assessment applications to reuse, recycling and circular practices for textiles: A review.

To understand which are the best strategies for textile waste management and to analyse the effects on the environment of applying circular economy practices to textile products, a review of 45 publications where life cycle assessment (LCA) is applied to these topics has been carried out. The separate collection of textiles, followed by reuse and recycling brings relevant environmental benefits, with impacts related to reuse resulting lower than those of recycling. At the opposite, when mixed municipal solid waste is addressed to energy recovery, the textile fraction is the second most impacting on climate change, right after plastics, while for landfill disposal impacts textiles directly follow the more biodegradable fractions. Textiles manufacturing using recycled fibres generally gives lower impacts than using virgin ones, with a few exceptions in some impact categories for cotton and polyester. The circular practices with the lowest impacts are those that ensure the extension of the textiles service life. Another aim of this review is to identify the main variables affecting the life cycle impact assessment (LCIA). These resulted to be the yield and material demand of recycling processes, the use phase variables, the assumptions on virgin production replaced by reuse or recycling, the substitution factor in reuse, and transportation data in business models based on sharing. Thus, in LCA modelling, great attention should be paid to these variables. Future research should address these aspects, to acquire more relevant data, based on industrial-scale processes and on people habits towards the circular economy strategies applied to textiles.