Data Science Applications in Circular Economy: Trends, Status, and Future.

The circular economy (CE) aims to decouple the growth of the economy from the consumption of finite resources through strategies, such as eliminating waste, circulating materials in use, and regenerating natural systems. Due to the rapid development of data science (DS), promising progress has been made in the transition toward CE in the past decade. DS offers various methods to achieve accurate predictions, accelerate product sustainable design, prolong asset life, optimize the infrastructure needed to circulate materials, and provide evidence-based insights. Despite the exciting scientific advances in this field, there still lacks a comprehensive review on this topic to summarize past achievements, synthesize knowledge gained, and navigate future research directions. In this paper, we try to summarize how DS accelerated the transition to CE. We conducted a critical review of where and how DS has helped the CE transition with a focus on four areas including (1) characterizing socioeconomic metabolism, (2) reducing unnecessary waste generation by enhancing material efficiency and optimizing product design, (3) extending product lifetime through repair, and (4) facilitating waste reuse and recycling. We also introduced the limitations and challenges in the current applications and discussed opportunities to provide a clear roadmap for future research in this field.

Can bioplastics always offer a truly sustainable alternative to fossil-based plastics?

Bioplastics, comprised of bio-based and/or biodegradable polymers, have the potential to play a crucial role in the transition towards a sustainable circular economy. The use of biodegradable polymers not only leads to reduced greenhouse gas emissions but also might address the problem of plastic waste persisting in the environment, especially when removal is challenging. Nevertheless, biodegradable plastics should not be considered as substitutes for proper waste management practices, given that their biodegradability strongly depends on environmental conditions. Among the challenges hindering the sustainable implementation of bioplastics in the market, the development of effective downstream recycling routes is imperative, given the increasing production volumes of these materials. Here, we discuss about the most advisable end-of-life scenarios for bioplastics. Various recycling strategies, including mechanical, chemical or biological (both enzymatic and microbial) approaches, should be considered. Employing enzymes as biocatalysts emerges as a more selective and environmentally friendly alternative to chemical recycling, allowing the production of new bioplastics and added value and high-quality products. Other pending concerns for industrial implementation of bioplastics include misinformation among end users, the lack of a standardised bioplastic labelling, unclear life cycle assessment guidelines and the need for higher financial investments. Although further research and development efforts are essential to foster the sustainable and widespread application of bioplastics, significant strides have already been made in this direction.

Investigation of waste characteristics and recycling behaviour at educational institutes.

In this study, the waste generation at the educational institutes chosen from four different levels (kindergartens, primary, secondary and high schools) in Istanbul was measured on-site and the contents of the waste thrown into the recycling bins were determined to specify capture rates. Separation and weighing processes were performed at 16 spots in high schools, 12 spots in secondary schools, 7 spots in primary schools and 7 spots in kindergartens. A survey was conducted to determine the students' awareness of recycling in these schools. It was revealed that the wastes produced from educational institutes are organics (36.4 %), paper (24 %), plastics (14.4 %), glass (8.1 %), metals (4.8 %) and miscellaneous (12.3 %). The survey results indicate that 93 % of the participants think recycling is important, 71 % of them throw their waste into suitable waste bins and 59 % of them know the location of the recycling bins. At the primary school level, a very high rate of paper waste (92.3 %) was reported in plastic bins while plastic waste collected in these bins remained only 5.7 %. It was also seen that glass waste captured in glass bins and metal waste in metal bins remain very low rates (20.9 % and 29.2 %, respectively) at the secondary school level. At the high school level, it was determined that the most commonly captured wastes in glass, plastics and paper bins are glass (47.5 %), plastic (43.2 %) and paper (32.5 %), respectively. Correlation analyses indicated a high positive correlation (p < 0.05) between particular types of waste.

Food waste tectonics: Points of friction between policy push and practice pull in council-led household-food-waste interventions in Australia.

Household food waste is increasingly recognised as a global wicked problem for its greenhouse gas emissions, economic damage, and resource loss. Although targeted in the UN's Sustainable Development Goals, countries can only respond according to their capacity. For Australia, national policy has put the pressure on states and territories to divert food waste away from landfill into a nascent circular economy. For councils, this increasingly means implementing a FOGO (Food Organics/Garden Organics) kerbside collection. Despite funding and infrastructure development, many are resisting. Framed by the tenets of policy diffusion, this paper presents the results of a nationwide exploratory survey aimed at identifying how and why council-based waste services staff resist, emulate or lead FOGO implementation. By assessing participants current kerbside systems and their attitudes towards household food waste management, the survey found costs, contamination, and capacity and were key concerns. However, responses to these varied considerably despite similarities of situation, often relating more to collaborative attitudes across waste services, council, and councillors. This paper recognises that a conducive environment for change is urgently needed for Australia to achieve organics diversion targets and shift household food towards a circular economy. It provides a starting point for further research into the complex and nuanced dynamics between council waste services and FOGO implementations, from external drivers and council paradigms to individual attitudes and perceptions.

Compression stress-strain curve of lithium slag recycled fine aggregate concrete.

As one of the key materials used in the civil engineering industry, concrete has a global annual consumption of approximately 10 billion tons. Cement and fine aggregate are the main raw materials of concrete, and their production causes certain harm to the environment. As one of the countries with the largest production of industrial solid waste, China needs to handle solid waste properly. Researchers have proposed to use them as raw materials for concrete. In this paper, the effects of different lithium slag (LS) contents (0%, 10%, 20%, 40%) and different substitution rates of recycled fine aggregates (RFA) (0%, 10%, 20%, 30%) on the axial compressive strength and stress-strain curve of concrete are discussed. The results show that the axial compressive strength, elastic modulus, and peak strain of concrete can increase first and then decrease when LS is added, and the optimal is reached when the LS content is 20%. With the increase of the substitution rate of RFA, the axial compressive strength and elastic modulus of concrete decrease, but the peak strain increases. The appropriate amount of LS can make up for the mechanical defects caused by the addition of RFA to concrete. Based on the test data, the stress-strain curve relationship of lithium slag recycled fine aggregate concrete is proposed, which has a high degree of agreement compared with the test results, which can provide a reference for practical engineering applications. In this study, LS and RFA are innovatively applied to concrete, which provides a new way for the harmless utilization of solid waste and is of great significance for the control of environmental pollution and resource reuse.

Assessing the Feasibility of Biorefineries for a Sustainable Citrus Waste Management in Korea.

Citrus fruits are one of the most widely used fruits around the world and are used as raw fruits, but are also processed into products such as beverages, and large amounts of by-products and waste are generated in this process. Globally, disposal of citrus waste (CW) through simple landfilling or ocean dumping can result in soil and groundwater contamination, which can negatively impact ecosystem health. The case of Korea is not much different in that these wastes are simply buried or recycled wastes are used as livestock feed additives. However, there are many reports that CW, which is a waste, has high potential to produce a variety of products that can minimize environmental load and increase added value through appropriate waste management. In this study, we aim to explore the latest developments in the evaluation and valorization of the growing CW green technologies in an effort to efficiently and environmentally transform these CW for resource recovery, sustainability, and economic benefits. Recent research strategies on integrated biorefinery approaches have confirmed that CW can be converted into various bioproducts such as enzymes, biofuels and biopolymers, further contributing to energy security. It was found that more efforts are needed to scale up green recovery technologies and achieve diverse product profiling to achieve zero waste levels and industrial viability.

Comparison of classification methods performance for defining the best reuse of waste wood material using NIR spectroscopy.

Recycling of post-consumer waste wood material is becoming an increasingly appealing alternative to disposal. However, its huge heterogeneity is calling for an assessment of the material characteristics in order to define the best recycling option and intended reuse. In fact, waste wood comes into a variety of uses/types of wood, along with several levels of contamination, and it can be divided into different categories based on its composition and quality grade. This study provides the measurement of more than a hundred waste wood samples and their characterisation using a hand-held NIR spectrophotometer. Three classification methods, i.e. K-nearest Neighbours (KNN), Principal Component Analysis - Linear Discriminant Analysis (PCA-LDA) and PCA-KNN, have been compared to develop models for the sorting of waste wood in quality categories according to the best-suited reuse. In addition, the classification performance has been investigated as a function of the number of the spectral measurements of the sample and as the average of the spectral measurements. The results showed that PCA-KNN performs better than the other classification methods, especially when the material is ground to 5 cm of particle size and the spectral measurements are averaged across replicates (classification accuracy: 90.9 %). NIR spectroscopy, coupled with chemometrics, turned out to be a promising tool for the real-time sorting of waste wood material, ensuring a more accurate and sustainable waste wood management. Obtaining real-time information about the quality and characteristics of waste wood material translates into a decision of the best recycling option, increasing its recycling potential.

Insights into plastic food packaging waste sorting behaviour: A focus group study among consumers in Germany.

Despite international efforts to foster the circular economy, plastic waste remains a major environmental problem. In the circular economy, the success of a waste management system depends, inter alia, on consumers properly sorting their plastic waste. Yet mis-sorting of plastic food packaging waste happens routinely. We sought to find out why and to outline the ways consumers prefer to receive information about waste sorting procedures. Tailoring information to consumer preferences can improve the effectiveness of waste management policy. Using the Motivation Opportunity Ability (MOA) framework to explain consumer behaviour, we conducted focus group discussions in two German cities. Our findings suggest that more accurate information and financial incentives best motivate consumers to sort waste correctly. Uncertainty and confusion over the packaging material are the most severe hindrances to correct sorting behaviour. The Internet and social media are preferred most for acquiring information on how to sort plastic food packaging correctly. Policymakers can use our results to adjust packaging and waste management regulations to help eliminate confusion among consumers and to facilitate their recycling intentions. Food industry practitioners and company decision makers can use our results to adjust their plastic packaging features to better match consumer preferences for easily recyclable waste.

Reuse of polymeric waste for the treatment of marine water polluted by diesel.

Accidental diesel spills can occur in marine environments such as harbors, leading to adverse effects on the environmental compartment and humans. This study proposes the surgical mask as an affordable and sustainable adsorbent for the remediation of diesel-contaminated seawater to cope with the polymeric waste generated monthly in hospital facilities. This approach can also be helpful considering a possible future pandemic, alleviating the pressure on the waste management system by avoiding improper mask incineration and landfilling, as instead occurred during the previous COVID-19. Batch adsorption-desorption experiments revealed a complete diesel removal from seawater after 120 min with the intact laceless mask, which showed an adsorption capacity of up to 3.43 g/g. The adsorption curve was better predicted via Weber and Morris's kinetic (R2 = 0.876) and, in general, with Temkin isotherm (R2 = 0.965-0.996) probably due to the occurrence of chemisorption with intraparticle diffusion as one of the rates-determining steps. A hysteresis index of 0.23-0.36 was obtained from the desorption isotherms, suggesting that diesel adsorption onto surgical masks was faster than the desorption mechanism. Also, the effect of pH, ionic strength and temperature on diesel adsorption was examined. The results from the reusability tests indicated that the surgical mask can be regenerated for 5 consecutive cycles while decreasing the adsorption capacity by only approximately 11%.

Absorbent hygiene products disposal behaviour in informal settlements: identifying determinants and underlying mechanisms in Durban, South Africa.

BACKGROUND: Within South Africa, many low-income communities lack reliable waste management services. Within these contexts, absorbent hygiene product (AHP) waste, including nappies (diapers), are not recycled, and are often dumped, ending up in watercourses and polluting the local environment. The structural barriers to collection which have been well explored, however the behavioural determinants of safe disposal for AHPs remains poorly understood. The purpose of this study is to determine the psycho-social factors driving AHP disposal behaviour for caregivers, while identifying potential underlying mechanisms (such as mental health), which may be influencing disposal behaviour, with the intention of informing a future, contextually appropriate and sustainable, collection system. METHODS: The cross-sectional study was conducted within three low-income communities located within eThekwini Municipality (Durban), South Africa. The study included a pre-study and a quantitative survey of 452 caregivers, utilising the RANAS approach of behaviour change. The quantitative questionnaire was based on the RANAS model to measure psycho-social factors underlying sanitary disposal of AHPs. Mental health was assessed using the Self-Reporting Questionnaire (SRQ-20). Statistical analysis involved regressing psycho-social factors onto disposal behaviour and exploring their interaction with mental health through a moderation model. RESULTS: Our findings suggest that one third of caregivers do not dispose of nappies sanitarily, despite intent (86.9%). Regression analysis revealed ten psycho-social factors which significantly predict the desired behavioural outcome, the sanitary disposal of AHPs. Caregivers with poor mental health were less likely to dispose of AHP sanitarily, which reflects previous research linking poor mental health and the impairment of health-related daily activities, particularly within vulnerable groups. Specifically, several psycho-social factors underlying were moderated by poor mental health, the prevalence of sanitary disposal of AHPs depended on mental condition of caregiver. CONCLUSIONS: Our findings confirmed the link between poor mental health and unsanitary AHPs disposal. This is especially relevant because poor mental health is common within South Africa. Addressing mental health problems within these communities is an essential step to providing sustainable waste management services. The findings informed an intervention strategy to implement a future collection system for these communities, and similar low-income or informal contexts within South Africa.

Recovery of plastic packaging from mixed municipal solid waste. A case study from Austria.

Austria must recycle more packaging materials. Especially for plastic packaging waste, significant increases are necessary to reach the EU recycling targets for 2025 and 2030. In addition to improving separate collection and introducing a deposit system for specific fractions, the share of plastic packaging in mixed municipal solid waste (MSW) could be utilized. In Austria, about 1.8milliontonnes of mixed MSW are generated. This includes about 110,000 t/a of plastic packaging waste. Most of the mixed MSW (94 %) is sent directly or via residues from pre-treatment, such as mechanical-biological treatment or waste sorting, to waste incineration. While materials such as glass and metals can also be recovered from the bottom ash, combustible materials such as plastics must be recovered before incineration. This work aims to evaluate the recovery potential of plastic packaging waste in mixed MSW with automated waste sorting. For this purpose, two of the largest Austrian waste sorting plants, with a total annual throughput of about 280,000 t/a, were investigated. The investigation included regular sampling of selected output streams and sorting analysis. The results show that the theoretical recovery potential of plastic packaging from these two plants is 6,500 t/a on average. An extrapolation to Austria results in a potential of about 83,000 t/a. If losses due to further treatment, such as sorting and recycling, are considered, about 30,000 t/a of recyclate could be returned to plastic production. This would correspond to an increase in plastic packaging recycling rate from 25 % to 35 %.

New multi-source waste co-incineration and clustering park operating model for small- and medium-sized city: A case study in China.

With improvements in urban waste management to promote sustainable development, an increasing number of waste types need to be sorted and treated separately. Due to the relatively low amount of waste generated in small- and medium-sized cities, separate treatment facilities for each waste type lack scale, waste is treated at a high cost and low efficiency. Therefore, industrial symbiosis principles are suggested to be used to guide collaborative waste treatment system of multi-source solid wastes, and co-incineration is the most commonly used technology. Most existing studies have focused on co-incineration of one certain waste type (such as sludge or medical waste) with municipal solid waste (MSW), but the systematic design and the comprehensive benefits on a whole city and park level have not been widely studied. Taking the actual operation of a multi-source waste co-incineration park in south-central China as an example, this study conducted a detailed analysis of the waste-energy-water metabolism process of MSW, sludge, food waste, and medical waste co-incineration. The environmental and economic benefits were evaluated and compared with the single decentralized waste treatment mode. The results showed that the multi-source waste co-incineration and clustering park operating model was comprehensively superior to the single treatment mode, greenhouse gases and human toxicity indicators were decreased by 11.87% and 295.74%, respectively, and the internal rate of return of the project was increased by 29.35%. This mainly benefits from the synergy of technical system and the economies of scale. Finally, this research proposed policy suggestions from systematic planning and design, technical route selection, and an innovative management mode in view of the potential challenges.

An Aspen plus process simulation model for exploring the feasibility and profitability of pyrolysis process for plastic waste management.

Plastics, integral to various human activities, have led to a surge in production, posing substantial challenges in waste management. The persistent non-biodegradability of plastics, taking over a century to decompose, necessitates exploration into technologies for their conversion into sustainable fuels. Pyrolysis, an oxygen-free thermal decomposition process, emerges as a promising avenue for producing liquid fuels from plastic waste. This study's primary objective is to create and validate an Aspen Plus simulation model, enabling techno-economic evaluation and sensitivity analysis of pyrolysis for converting waste plastics into liquid fuels. Critical parameters-temperature, retention time, and particle size-are examined for their impact on product yield and quality. The methodology involves model development, validation, and subsequent simulations with various waste plastic types under different pyrolysis conditions. Experimental investigation using waste high-density polyethylene (HDPE) in an auger reactor yielded an oil yield of 61.29%, char yield of 10.98%, and syngas yield of 27.73% at 525 °C. Post-validation against this data, the model explored four plastic types, revealing significant influences of plastic type and reactor temperature on product yields. Polystyrene (PS) at 500 °C produced the highest oil content at 83.69%, with temperature affecting yield before secondary cracking. Techno-economic evaluation for a pyrolysis plant processing 10,000 tons of waste HDPE annually indicated a minimum selling price (MSP) of $302.50/ton, a net present value (NPV) of $12,594,659.7, and a 1.03-year payback period. This study provides crucial insights for designing an economically viable and sustainable pyrolysis process, guiding further research and industrial implementation.

Solid waste management practices and challenges in Besisahar municipality, Nepal.

This study is a comprehensive assessment of the waste management system in Besisahar municipality. Information and some data have been collected from the municipality of Besisahar, followed by interviews with municipal officials responsible for waste management, stakeholders, waste workers, and residents. A total of 230 households, 20 schools, 10 government and private offices, 10 financial institutions, 60 commercial hotels, restaurants, and shops, and 20 medical shops and healthcare institutions, were selected in this study by random sampling. An extensive field study was conducted within all municipal wards and at dump sites. The results indicated that 42.14% of solid waste was collected through door-to-door collection services, 5.87% was mismanaged in open public places, 11.21% was used as compost manure, and the rest was discarded on riverbanks, dug up, and burned. A large component of the characterization of household waste consisted of organic waste (68.03%), followed by paper/paper products (8.13%), agricultural waste (5.5%), plastic (5.21%), construction (3.81%), textile (2.72%), metals (0.54%), glass (1.01%), rubber (0.10%), electronic (0.05%), pharmaceutical (0.1%) and others (4.78%) in the Besishahar municipality. Solid waste generation was found to be at 197.604 g/capita/day, as revealed by cluster sampling in 230 households. Around 4.285 tons-solid waste/day were generated in urban areas, while 16.13 tons-solid waste/day was estimated for the whole municipality. An important correlation between the parameters of solid waste was found by statistical analysis. Currently, solid waste is dumped on riverbanks, open fields, and springs, creating environmental and health hazards. The findings of this study will be useful to Besisahar municipality and its stakeholders in forming policies that facilitate waste management practices in this region and promote sustainable waste management systems.

Consumer behavior in the model of the circular economy in the field of handling discarded items.

The circular economy is a way of eliminating the shortage of raw materials that Europe is currently facing. However, it is necessary to explicitly identify the problems that prevent greater involvement in the CE. This article is focused on consumers and how they treat discarded or non-functional items. The aim was to fill the research gap, i.e. to compile a suitable CE model and define a methodology that would ensure the efficient disposal of non-functional or unsuitable items by consumers. An original methodology was drawn up to conduct the representative research, designed to lead to the practical application of the proposed CE model. The research explored how consumers treat non-functional or unsuitable items, the costs they incur in discarding, renovating, reusing, and recycling such items, and the alternative costs of unsorted municipal waste. After the data had been implemented into the model the circular economy was proven to have an economic benefit for the national economy in all groups. However, the economic disadvantage for consumers was also calculated, where the cost of involvement in the CE is higher than the cost of unsorted municipal waste. This means that people are motivated to play a part in the CE more by their own responsible approach to life, or social pressure from those around them. Based on this research it may be said that economic aspects are one reason that consumers tend to be reluctant to get more involved in the CE. Unless there is a significant rise in the cost of municipal waste that would motivate consumers to move towards the CE for financial reasons, in order to support the CE consumers need to be better stimulated, educated and informed as much as possible through the media.

The FOODRUS index: Assessing suitability for effective food loss and waste prevention management under an integral perspective.

The impact of food loss and waste (FLW) generation on food supply chains' (FSC) sustainability represents a challenge embodied in the Sustainable Development Goal (SDG) 12.3. This problem requires a methodology to measure such an impact in a rigorous, holistic, and standardized way that can be applied to any FSC. This paper aims to develop and validate a single index to assess the readiness of FSCs to implement FLW prevention strategies and measure their impact: the so-called FOODRUS index. The co-creation methodology followed incorporates experts and FSC stakeholders feedback. The index has been validated in 3 FSCs: The Slovak pilot scored 74.35%, the Spanish pilot reached 68.79%, and the Danish pilot was rated 61.14%. Its calculation, eased by the FOODRUS index self-assessment tool (described in the Appendix), allows quick diagnosis of the FSC capability to implement FLW prevention strategies considering both the knowledge provided by experts and the experience of the FSC stakeholders that participated in its co-creation process. In this way the FSC can assess its FLW prevention performance at a strategic and management level, with the aim of improving its sustainability impact.

Optimizing City-Scale Demolition Waste Supply Chain Under Different Carbon Policies.

In order to establish a green, low-carbon circular development economic system, imperative goals include achieving carbon peaking and carbon neutrality. This research delves into the resource utilization of city-scale demolition waste (C&DW), aligning with environmental protection needs and sustainable development principles. The paper introduces a unique closed-loop supply chain (CLSC) model tailored for C&DW and employs a distinctive mixed integer nonlinear programming (MINLP) model for optimization. Guangzhou serves as a case study for thorough analysis, verification, and practical application of the proposed model, especially under diverse scenarios of carbon price (CP) and carbon trading (CT) policies. The key conclusions drawn from this study include the following: (1) The cost of carbon emissions is intricately influenced by both carbon emissions and carbon price, with the latter effectively regulating the carbon emissions during C&DW recycling. (2) The implementation of a CT policy, with a fixed carbon price, contributes to a further reduction in the cost of C&DW recycling treatment. (3) Under equivalent conditions, the CT policy demonstrates the potential to decrease costs and enhance the economic benefits within the building environmental protection product market. The research outcomes not only contribute to the advancement of management theory in the C&DW recycling supply chain (SC) but also provide a robust theoretical foundation for governmental initiatives aimed at introducing effective C&DW recycling management policies.

Environmental sustainability assessment of a new food waste anaerobic digestion and pyrolysis hybridization system.

This research conducted an environmental life cycle assessment (LCA) to evaluate an anaerobic digestion-co-pyrolysis (ADCo-Py) system in which pyrolysis was added to traditional food waste (FW) anaerobic digestion (AD) systems to treat the solid fraction and impurities separated from FW. The solid fraction, including impurities such as wooden chopsticks, plastics, eggshells, and bones, is usually incinerated, while pyrolysis can be a viable alternative to optimize FW treatment. The environmental impact of ADCo-Py was compared with stand-alone AD, pyrolysis, and ADCo-INC (AD with incineration of separated solids). The results indicated that both ADCo-Py (-1.726 kg CO2-Eq/kgFW) and ADCo-INC (-1.535 kg CO2-Eq/kgFW) outperform stand-alone AD (-0.855 kg CO2-Eq/kgFW) and pyrolysis (-0.181 kg CO2-Eq/kgFW) in mitigating global warming potential (GWP). Additionally, pretreatments were found to have the most significant influence on GWP, ecotoxicity potential (ETP), and acidification potential (AP). The two-step pretreatment in ADCo-Py, including the separation of solids and drying, significantly improved the environmental sustainability of the system when compared with standalone pyrolysis.

Life cycle thinking for the assessment of waste and circular economy policy: status and perspectives from the EU example.

Life cycle thinking methods such as life cycle assessment (LCA) and costing (LCC) were originally developed to assess the performance of products and services (business-making decisions). However, they are increasingly deployed to support policy-making along the entire policy cycle, including via impact assessment (IA) of different policy options. These applications are associated with a number of challenges, mainly related to the dynamic and prospective nature of policy IA, typically forward-looking into 10-20 years ahead. This requires the application of prospective scenario analyses to develop the baseline scenario, reflecting the 'do nothing' into the future (business-as-usual), and the alternative scenarios, reflecting the consequences incurred by the implementation of the policy options under study. Such prospective and broadened boundary nature of policy IA challenges traditional LCA/LCC practices mostly based on retrospective, static scenarios and datasets. The present study provides an overview of recent IA studies supporting waste policy to show the state-of-the-art and the main challenges associated with the application of life cycle methods in IA, focusing on the most recent EU waste and circular economy policies. Moreover, since specific and transparent guidance on how to implement consistently these methods in policy IA is lacking, the study provides an initial guidance for application of life cycle thinking in IA drawing upon the knowledge obtained conducting waste policy IA studies. Key challenges in the field are still to be addressed, and might inspire further research to improve the application of life cycle thinking to policy assessment.

Overview of municipal solid waste management in sub-tropical climatic region of North Eastern India.

Municipal solid waste management (MSWM) is perceived as a global issue regardless of the place of waste generation. The amount of unmanaged waste is increasing rapidly, along with its impact on the environment and human health. In hilly areas, specifically the North Eastern Region (NER) states of India, due to the unique topography coupled with socio-economic factors, there are inadequate waste management practices marked by insufficient infrastructure, minimal research studies, and limited data availability. This paper comprehensively reviews the existing status of MSWM practices and waste treatment technologies, identifies the challenges, and discusses the prospective approaches for MSWM in NER states of India. NER, is characterized by its hilly terrain and has the most diverse demographic profile in the country. The study highlights the notable increase in waste generation in the urban population in NER. The total amount of waste generated in NER is about 2907 tons per day, with a collection rate of 86.96%, treatment at 31.09%, and landfilling at 33.67%. The biodegradable fraction makes up the majority of waste composition (more than 50%) in NER, followed by recyclables and inert. The existing MSWM consists of waste collection, transportation, and disposal with limited source segregation and treatment. All the states of NER practice open dumping and burning as the primary waste treatment and disposal system. The study discusses the challenges and prospects to ensure effective MSWM in NER. This review is a region-specific study that considers cultural diversity, topography, and socio-economic dynamics. The outcome of this review will be helpful to the researchers and policymakers in making appropriate waste management plans and improve the MSWM system in NER.