Material Recovery Research Articles

Analyzing the lifecycle of solar panels including raw material sourcing, manufacturing, and end-of-life disposal

The lifecycle of photovoltaic systems, encompassing the procurement of raw materials, manufacturing processes, and eventual disposal at the end of their operational lifespan, presents considerable ecological challenges notwithstanding their contribution to the enhancement of renewable energy sources. This research offers an exhaustive examination of the ecological ramifications associated with each phase of the lifecycle of photovoltaic systems. The extraction of essential materials, including silicon, silver, and rare earth metals, necessitates energy-demanding processes and leads to resource depletion, while the manufacturing phase is associated with the emission of greenhouse gases and resource consumption, particularly in the fabrication of crystalline silicon panels. The disposal at the end of life is becoming increasingly significant, as retired panels accumulate, and existing recycling technologies provide minimal recovery of valuable materials. Despite the substantial reduction in greenhouse gas emissions attributable to solar panels throughout their operational lifespan, there is a pressing need for enhancements in material efficiency, manufacturing methodologies, and recycling frameworks to mitigate their lifecycle repercussions. The investigation underscores the imperative for sustainable methodologies, circular economy paradigms, and policy measures to guarantee the enduring environmental sustainability of solar energy.

Sustainability and Environmental Performance in Selective Collection of Residual Materials: Impact of Modulating Citizen Participation Through Policy and Incentive Implementation

The effective management of urban waste represents a growing challenge in the face of demographic evolution and increased consumption. This study explores the impacts of municipal strategic decisions on household waste management behaviours and sustainability performance outcomes through agent-based modelling. Using data from Gatineau and Beaconsfield in Quebec, Canada, the model is calibrated and validated to represent diverse urban contexts. Our analysis demonstrates that reducing collection frequency leads to notable increases in participation rates, reaching 78.2 ± 5.1% for collections every two weeks and 96.5 ± 8.3% for collections every five weeks. While this reduction improves bin filling levels, it concurrently decreases the recovery of recyclable materials by 2.8% and 19.5%, significantly undermining the environmental benefits of the recycling program. These findings highlight a complex interplay between collection frequency, citizen participation behaviour, waste stream characteristics, and overall environmental performance. While reducing collection frequency initially appears beneficial, it leads to operational challenges and increased CO2 emissions due to reduced material recovery. The research emphasises the need for tailored holistic waste management strategies that optimise performance outcomes while minimising environmental impacts. By understanding these dynamics, municipalities can develop more effective waste management policies that promote sustainability.

An Environmental Assessment of Municipal Solid Waste Management Strategies in Riyadh, Saudi Arabia: A Comparative Life Cycle Analysis

The environmental implications of various municipal solid waste (MSW) management systems in Riyadh, Kingdom of Saudi Arabia, were analysed considering the Riyadh Green Initiative through a comprehensive Life Cycle Assessment (LCA). This study evaluates five distinct scenarios: unsanitary landfilling (Sc0), incineration (Sc1), and a combination of technologies such as anaerobic digestion (AD) and a material recovery facility (MRF) in scenarios Sc2–Sc4. These scenarios were assessed using GaBi 9.2.1 software, employing the impact methodology outlined by CML (2001) to evaluate eight impact categories, including Global Warming and Acidification Potentials, among others. The findings indicate that scenarios incorporating the treatment of 100% of recyclable and organic waste through AD exhibited substantial environmental benefits. Additionally, Sc2 demonstrated the lowest environmental burdens across all impact categories. In contrast, Sc0 ranked the worst in all categories due to the absence of gas and leachate treatment. The results were shown to be reliable when compared qualitatively to previous studies. Furthermore, a sensitivity analysis was conducted to assess this study’s system boundaries and the impact of the MRF rate. Overall, this research provides valuable insights for optimising MSW management practices in Riyadh, aiming to reduce their environmental impacts and align with the goals of the Riyadh Green Initiative.

Normative influence on intention to segregate household waste: Reflections from a low-middle income city in urban Africa

ABSTRACT Household waste segregation is crucial for better domestic waste management, successful material recovery programs, environmental pollution reduction, and the promotion of circular economies. While prevalent in developed nations, global adoption of household waste segregation is lacking, particularly evident in emerging economies where city authorities grapple with mounting volumes of mixed waste. Our study, conducted in the Greater Accra Metropolitan Area, surveyed 1,245 households using a multi-stage sampling technique. Employing structural equation modeling, we assessed how descriptive, injunctive, and moral norms influence individuals’ intention to segregate household waste, considering sociodemographic attributes and policy effectiveness. Findings underscore the significance of descriptive and moral norms, affirming their impact on pro-environmental behaviors. The study reiterates the influential role of education, age, and neighborhood characteristics in moderating these norms and recommends the implementation of persuasive policies, like waste-for-cash incentives, backed by logistical support, infrastructure, and public education to foster household waste segregation and elevate waste management practices.

Assessment of Different Application Grades of Post-Consumer Recycled (PCR) Polyolefins from Material Recovery Facilities (MRFs) in the United States

Assessment of Different Application Grades of Post-Consumer Recycled (PCR) Polyolefins from Material Recovery Facilities (MRFs) in the United States

Influence of green solvents on the recovery of cathode active materials from electrode scraps: A comparative study

Direct recycling of cathode materials from spent Li-ion batteries (LIBs) or electrode scraps necessitates the efficient recovery of active materials from the aluminum foil. The variability in electrode types and recovery processes across previous studies complicates the comparative assessment of the recovery performance of green solvents. In this study, we evaluated the performance of three green solvents—triethyl phosphate (TEP), dihydrolevoglucosenone (Cyrene), and propylene carbonate (PC)—in recovering valuable active materials from industrial-grade cathode scraps. Using ultrasonication, we developed a standardized, energy-efficient recovery process that eliminated the need for conventional stirring and achieved complete cathode delamination from the aluminum foil. Furthermore, we successfully recovered the used green solvents after the process, ensuring their reuse and supporting a circular economy. The recovered materials retained their original morphology, chemical composition, and crystalline structure; however, the presence of surface impurities varied significantly depending on the green solvent used. These impurities had a considerable impact on the electrochemical performance of the recovered materials. TEP and PC yielded high-purity active materials and aluminum foils suitable for reuse or direct recycling, while Cyrene resulted in substantial residues of PVDF/solvent, requiring additional post-processing. Additionally, the recyclability of these green solvents was influenced by their solubility power for PVDF. This study provides valuable insights into the green solvent-based recycling process, laying the groundwork for future sustainable practices in LIB recycling.

Simulation-Based Design for Recycling of Car Electronic Modules as a Function of Disassembly Strategies

Modules (or parts) of a car are a complex functional material combination used to deliver a specified task for a car. Recovering all materials, energy, etc., into high-grade materials at their end of life (EoL) is impossible. This is dictated by the second law of thermodynamics (2LT) and thence economics. Thus, recyclability cannot be conducted with simplistic mass-based approaches void of thermodynamic considerations. We apply, in this paper, a process simulation model to estimate the true recyclability of various SEAT (Volkswagen Group) car parts within the EU H2020 TREASURE project. This simulation model is developed with 190 reactors and over 310 feed components with over 1000 reaction species in the 880 streams of the flowsheet. The uniqueness of the work in this paper is to apply the full material declaration (FMD) and bill of materials (BOM) of all 310 materials in the parts as a feed to the process simulation model to show the parts’ true recyclability. We classified all parts into categories, i.e., copper-rich, steel-rich and plastic-rich, to maximally recover metals at the desired material quality, as well as energy. Recyclability is understood to create high-grade products that can be applied with the same functional quality in these parts. In addition, disassembly strategies and related possible redesign show how much recyclability can be improved. Process simulation permits the creation of alloys, phases, materials, etc., at a desired quality. The strength of the simulation permits any feed from any End-of-Life part to be analyzed, as long as the FMD and BOM are available. This is analogous to any mineral and metallurgical engineering process simulation for which the full mineralogy must be available to analyze and/or design flowsheets. This paper delivers a wealth of data for various parts as well as the ultimate recovery of materials, elements, and energy. The results show clearly that there is no one single recycling rate for elements, materials, and alloys. It is in fact a function of the complexity and material combinations within the parts. The fact that we use a thermochemical-based process simulator with full compositional detail for the considered parts means full energy balances as well as exergy dissipation can be evaluated. This means that we can also evaluate which parts, due complex mixtures of plastics, are best processed for energy recovery or are best for material and metal recovery, with thermochemistry, reactor technology and integrated flowsheets being the basis.

Potential of polyethylene terephthalate (PET) in a circular economy from a life cycle assessment perspective - a case study for anaesthesia and surgical instrument packaging waste in Australia

Plastics are a versatile material group with many applications in the healthcare sector. Clinicians, particularly in the operating rooms, have become increasingly dependent on single-use instruments and consumables typically packaged in Polyethylene Terephthalate (PET) resulting in significant amounts of PET waste. In this study, a life cycle assessment (LCA) methodology based on ISO 14040/44 is conducted to assess the environmental impacts of existing and potential future end-of-life options for PET anaesthesia and surgical instrument packaging waste in an Australian hospital context. The results show the reduction potential of environmental impacts by recycling of PET waste via direct collection or in Materials Recovery Facility (MRF) in Australia, Indonesia and New Zealand. When replacing end-of-life options such as landfill or incineration with recycling, a reduction of 88% of total Climate Change (CC) impact can be seen. Furthermore, there is a reduction in environmental impacts across other impact categories through this change. Even if the recyclate quality (up to 30%) was reduced, there is a significant reduction in the environmental impacts. The transition of end-of-life options to recycling offers the potential for reduction of emissions and enables a circular economy for plastics. Furthermore, based on the results of LCA, opportunities and challenges of circular economy pathways in health industry are identified and discussed in this study.

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.

Spent lithium-ion battery recycling: Process optimization and carbon footprint analysis based on thermal mechanical force

ABSTRACT With the increasing number of spent lithium-ion batteries, the development of efficient and environmentally friendly recycling technologies has become a key research focus. This study aims to establish a physical recycling method that integrates thermal treatment and mechanical separation to enhance the recovery rate of LiFePO4 materials while minimizing environmental impact. The process combines thermal treatment, mechanical separation, and air separation, with key factors influencing material separation and recovery efficiency analyzed through single-factor and variance analyses. Additionally, the carbon footprint of the recycling process was assessed using SimaPro software. The experimental results indicate that within a temperature range of 270°C–300°C, thermal treatment effectively separates LiFePO4 from aluminum foil, achieving a recovery rate of 96.88%. The air separation experiments further demonstrate that at an airflow speed of 20 m/s, the cathode material and current collector can be efficiently separated. Moreover, the carbon footprint analysis shows that this method significantly reduces carbon emissions.

Scenario analysis of waste tires from China's vehicles future

As a byproduct of vehicles, tires are utilized in large quantities with the widespread promotion of vehicles. Long-term accumulation of non-degradable waste tires occupies land resources and poses severe environmental threats. Projecting future waste tire volumes provides a scientific basis for preventing excessive accumulation, enables proactive planning of recycling strategies, reduces environmental pollution and promotes waste tire recycling. Using a bottom-up Road Transport Waste Tire Stock model, this study projects vehicle stocks and corresponding annual increases in waste tires from 2002 to 2050. The study reveals that China's vehicle and waste tire stock follows an S-curve growth. Vehicle ownership is projected to increase from 276 million in 2020 to 490–583 million by 2050. Between 2002 and 2030, waste tire generation from vehicles is expected to rise from 4.79 million tons to 18.13–18.57 million tons. By 2050, growth will slow, but the total output will still reach 18.90–19.85 million tons, with cargo trucks contributing 68%. By 2050, Shandong is the leading province in waste tire production, generating 1.82 million tons annually, accounting for 9.1%. Hainan will see the highest growth rate by 2030, with a 40% increase from 2020 levels. The study, based on current policies, presents three recommendations: improving waste tire tracking and recycling systems, implementing region-specific management strategies, and promoting the resource recovery of raw materials from cargo trucks waste tires. These measures aim to enhance waste tire management and foster rubber resource recycling.

Magnetic Supraparticles as Identifiers in Single-Layer Lithium-Ion Battery Pouch Cells.

The development of effective recycling technologies is essential for the recovery and reuse of the raw materials required for lithium-ion batteries (LIBs). Future recycling processes depend on accessible information, necessitating the implementation of a digital battery passport. The European battery regulation mandates the use of a machine-readable identifier physically attached to the batteries for accessing digital information. Since externally applied optical labels are vulnerable to mechanical damage, technologies for identification without these restrictions could be beneficial. This study demonstrates that magnetic supraparticles (SPs) can be used for contactless identification of lithium nickel manganese cobalt oxide (NMC) battery pouch cells via magnetic particle spectroscopy (MPS) and that multiple pouch cells can be discriminated based on their specific magnetic code. A comparison of three independent model scenarios revealed that the detection of SPs and the impact on cell performance are dependent on the integration location. The results validate the concept of magnetic identification in metallic environments with MPS as an alternative to optical labeling methods. This study provides a foundation for the development of a new selective labeling and identification technology for batteries, with the potential to facilitate recycling and contribute to a more sustainable future.

Methodology and Database for the Quantification of the Technical Recyclability of Electrical and Electronical Equipment Demonstrated on a Smartphone Case Study

Assessing a given product’s design and its recyclability using mass flow analysis based on the material separation and recovery rates of individual recycling processes under realistic conditions can support design decisions promoting better recyclability. EN 45555 defines the calculation of the technical recyclability of electrical and electronic equipment (EEE). However, the lack of specific recycling rates for material or processes often leads to either too small or too high recyclability values. Herein, an extensive database of such recycling rates is presented. Moreover, the quality of recycling is considered. The typical classification into “recycled” and “lost” is expanded into four categories, namely “circular”, “recycled”, “alternate material recovery” and “lost”. The recycling rate database includes yields for all four categories and covers 30 materials for 14 recycling processes relevant in waste EEE (WEEE) treatment. These data enable a detailed calculation of the recyclability of various EEE for multiple recycling scenarios covering the entire WEEE recycling chain. Fraunhofer IZM performed an internal critical review of the data. The recycling rates database can act as a solid foundation for comparing the recyclability of various electronics in different scenarios and recyclability indices. For example, the recyclability of typical smartphones is investigated comparing different dismantling and recycling scenarios highlighting the potential of both database and methodology.

Solvolysis and oxidative liquefaction of the end-of-life composite wastes as an element of the circular economy assumptions

In pursuit of sustainable development, recycling composite waste is a crucial challenge as well as an opportunity to support the progress towards eco-friendly materials management and circular economy practices. The current study brings together two modern recycling techniques solvolysis and oxidative liquefaction to recycle five types of composite waste materials including wind turbine blades (WTBs), composite pipes, personal protective equipment (PPEs) used in the medical sector, photovoltaic (PV) panels and municipal solid waste (MSW). Following a well-structured experimental design for each type of waste the solvolysis was performed at a temperature range of 100–190 °C, process time within the range of 1–3 h, and catalyst (TBD) concentration within the range of 0.015–0.025 mol, end with ethylene glycol and 1-methyl-2-pyrrolidinone in a 1:1 M ratio, while depending on the material evaluated, the oxidative liquefaction process was conducted at temperatures between 250 and 350 °C for WTB and between 200 and 300 °C for PPE, MSW, and PV. Oxidant concentrations, reaction time and pressure (15–45%, 30–90 min, 20–40 bar for WTBs, 30–60%, 45 min, 30 bar for remaining waste types) were studied in addition to highly variant waste-to-liquid ratio from 5 to 25% for WTB, 3–7% for PPE and MSW, and 12.5–37.5 for PV. Prior to experimental investigation, surface morphologies and chemical studies of the waste material were performed by scanning electron microscope (SEM) and Fourier transform infrared FT-IR spectroscopy, while after experimentation total polymer degradation (TPD) was calculated and liquid products were analysed through gas chromatography with flame ionisation detection (GC-FID). Following the solvolysis, 50–60% TPD was obtained, allowing for the recovery of glass fibres (GF) with average lengths of 50–60 mm and a maximum length of 650 mm. This allowed for the recovery of GFs with average lengths of 50–60 mm and a maximum length of 650 mm. In the case of oxidative liquefaction, total polymer degradation of 72–100%, 52–100% and 55–100% was achieved, depending on the investigated waste, i.e. WTB, PPE and MSW, respectively. The yield of oxygenated chemical compounds depended upon the types and composition of waste, but acetic acid was the main acid while WTB, PPE, and MSW, the liquid samples contained phenol also. Involved chemistry and possible degradation pathways of complex composite wastes are discussed in detail to enhance the recycling process and material recovery.

Valorization of process water from hydrothermal carbonization of food waste by dark fermentation

Hydrothermal carbonization (HTC) of food waste produces hydrochar—a suitable biofuel—and process water (PW), which has a high organic content suitable for material and energy recovery. In this work, we study the effect of pH (4.8, 5.3, and 6.0) and organic loading rate (OLR; 2.5, 5.0, and 7.5 gCOD L−1 d−1) throughout the dark fermentation (DF) of PW from the HTC of food waste (180 °C, 1 h) in a continuous stirred tank reactor. The highest hydrogen yield (197.5 mL H2 L−1 d−1) was reached at pH 4.8 and OLR 5 gCOD L−1 d−1, associated with a prevalence of Clostridium bacteria. The highest volatile fatty acids concentration (10.2 gCOD·L−1) was achieved at pH 4.8 and OLR 7.5 gCOD L−1 d−1, with a dominance of Actinobacteria phylum. The integrated system HTC-DF allowed a potential energy recovery of 11.2 MJ kg−1.

A-092 Siemens Healthineers Commitment to Quality - A Focus on Continuous Improvement and Customer Experience

Abstract Background It is necessary that each step of in vitro diagnostic assay development and manufacturing processes be documented and executed in alignment with established quality management systems. Here, we describe how Siemens Healthineers (SHS) maintains assay traceability and focus on continuous improvement using the Atellica® CH A-LYTE® Integrated Multisensor Technology (IMT) assays measuring electrolytes sodium (Na), potassium (K), and chloride (Cl) as a prime example. Methods Establishing an unbroken chain of comparison from the National Institute of Standards and Technology (NIST) higher standard references to the product calibrators ensures accurate value assignment within stated measurement uncertainties. Traceability and standardization are achieved by creating a panel of 10 serum anchor pools spanning the analytical measuring interval for each electrolyte: Na, K, and Cl. The concentrations of the anchor pools are determined at a reference laboratory using methods calibrated with standard solutions derived from NIST reference material. These serum anchor pools are used by SHS, assigning values to product calibrator material which maintains the chain of traceability to the primary reference methods. In addition to traceability, onboard stability for the A-LYTE® IMT multisensor is continuously monitored and evaluated against allowable drift limits for each electrolyte. Although observed drift was within allowable limits, a design change was implemented to improve recovery drift over the use life of the sensor. Results To ensure consistent, robust, and accurate performance of the A-LYTE IMT, a strict set of testing procedures are used to verify the accuracy of value assignments for each manufactured lot of master standards. The recovery of the NIST standard reference material must fall within manufacturer established acceptable bias limits. Consistency over nine master lots is shown with bias ranging from -0.9% to +1.9%, -2.4% to +1.8% and -1.8 to +0.5%, for Na, K and Cl, respectively. By further optimizing the amount of Na ionophore and the polymer matrix of the Na sensor, drift over the use life was minimized and onboard stability improved. Prior to making the sensor change, customer Na QC data at 116 mmol/L showed an SD of 1.1 mmol/L (n=585), whereas the precision improved to an SD of 0.6 mmol/L (n=470) post-optimization. As Manufacturers optimize assay performance, it may become necessary for laboratories to re-evaluate reference intervals for their patient populations. For example, one large integrated delivery network established a new reference interval for patient anion gap (AG). A re-evaluation of the historical AG reference interval which was 5-15 mmol/L identified the need for an update. AG values were calculated from 16,948 healthy patients and used to establish a new reference interval of 2-10 mmol/L. Conclusions Accurate clinical laboratory measurements are critical for diagnosing, monitoring, and treating diseases. A-LYTE assays have an unbroken chain of traceability to NIST reference material and minimal drift over the life of the multisensor. Continuous monitoring to identify improvement projects and rigorous control systems ensure sensor performance over time. This provides confidence that the patient results produced by the laboratory are accurate and consistent over time and across different laboratory locations.

Identifying Strategies to Cultivate Students’ Attitude Towards Circular Economy

Circular economy (CE) in Technical and Vocational Education and Training (TVET) refers to an economic approach that promotes efficient use of resources, material recovery, and waste reduction through vocational education. Despite various activities and programs conducted by TVET instructors to promote the circular economy, reports indicate that students' attitudes towards the environment remain at a moderate level. This paper aims to identify strategies that can be implemented to foster students' interest in practicing the circular economy within the context of TVET. This study uses the Nominal Group Technique (NGT) as an alternative approach to suggest initiatives that can foster students' attitudes towards the circular economy. The process involved silent idea generation, round robin, discussion, two rounds of initial voting, and a final stage survey to determine the priority list. Five content experts participated in the NGT meeting. Initially, 50 strategies were identified. Through the NGT process, 20 important strategies were selected to cultivate students' attitudes towards the circular economy. These strategies include waste management workshops, environmental programs and activities at institutions, conducive public sector ecosystem (EKSA) in institutions, homes and neighborhoods, information boards, simulation outside the classroom, daily routines, campaigns, neighborhood activities, sale of used oil, sale of recycled goods, innovation, waste segregation, cultivating student awareness, application in teaching, motivation, moral support, cleanliness and cheerfulness competitions, environment week, incorporating circular economy in the syllabus, and cross-curricular elements. The identified strategies are expected to assist stakeholders in overseeing the implementation of environmental awareness programs in schools, colleges, and TVET institutions, with the goal of improving student attitudes and transforming TVET education towards greater circular economy awareness.

Non-recyclable municipal solid waste characterization and pyrolysis for energy recovery

European regulations require that by 2030 waste suitable for recycling, material recovery, or energy recovery will no longer be allowed in landfills. MSW composition in non-recyclable containers affects what measures for recovery could be implemented. This study is a screening examination of 32 non-recyclable MSW samples in the Getafe municipality (Spain). In addition to non-combustible elements, MSW is separated into 15 waste materials. Merely 18.1 % of the non-recyclable component is placed in appropriate containers. Composition of all materials is analyzed. MSW samples are grouped into six clusters with similar properties using the K-nearest neighbor methodology. Representative sample from each cluster is pyrolyzed at 520 °C. The main product of pyrolysis is liquid, which makes up 57.9 wt%, while solid and gas fractions are 16.4 and 16.5 wt%, respectively. Liquid fraction is a blend of aromatic, aliphatic, oxygenated, and nitrogenated compounds, while gas fraction is mainly CO2.

Effectiveness of NGOs in mountainous solid waste management: A case study from Healing Himalayas in Rakchham, Himachal Pradesh, India.

Non-governmental organizations (NGOs) play a critical role in addressing solid waste management (SWM) challenges in remote mountain communities, including the ecologically fragile Himalayan region. This study evaluates the impact of Healing Himalayas, an NGO, in Rakchham village, Himachal Pradesh, India. The objectives were to evaluate the effectiveness of Healing Himalayas' decentralized SWM model in promoting stakeholder engagement and resource recovery, assess the role of collaborations between local authorities and the NGO in financing waste management practices, investigate the influence of tourism and seasonal variations on solid waste generation patterns and waste management practices in Rakchham, and material recovery facilities, followed by glass (36.7%), paper/cardboard (18.4%) and metal (4.1%). A fee-based system involving the local village council funded waste operations. Waste generation exhibited significant seasonal fluctuations, with tourism influxes driving increased volumes. Healing Himalayas' initiatives promoted community participation, with over 15 awareness workshops conducted. Key challenges included limited financial resources, inadequate infrastructure, lack of advanced treatment facilities and need for context-specific solutions like efficient wet waste management in cold climates. The study highlights Healing Himalayas' decentralized model's success in fostering stakeholder engagement, behavioural change and resource recovery. The findings inform effective strategies for NGO-led waste management initiatives tailored to remote Himalayan communities.

Landfill mining: A step forward to reducing CH4 emissions and enhancing CO2 sequestration from landfill

Landfill management is a major challenge for sustainable development in terms of climate change and resource scarcity. Landfill leachate contains high concentrations of nitrogen (N) and phosphorus (P), which cause eutrophication if discharged improperly. However, the nutrients can be recovered and reused as fertilizers for agriculture, contributing to resource recovery, circular economy, food security, and net zero emissions. Recent advances in landfill management have transformed landfills into resource recovery facilities that can produce nutrient-energy-material (NEM) products for applications through biological or physico-chemical process. Through a literature survey, this article reviews NEM recovery from landfills such as biogas production and composting. This work also discusses the benefits and challenges of NEM recovery for sustainability transition towards net zero emissions, while analyzes knowledge gaps and future research directions for landfill management and NEM recovery. It was conclusive from 193 articles published between 1993 and 2024 that landfill mining presents a promising solution for mitigating CH4 emissions and enhancing CO2 sequestration, both critical in reducing the overall greenhouse gas footprint of waste management. From landfill leachate and/or landfill gas, engineers can recover and recycle nutrients (for fertilizer), materials (for chemistry), and biogas (for electricity). Through landfill management, roadmaps towards decarbonization can be cost-effective and sustainable so that a maximum value of the waste can be extracted before it is discarded. Key findings reveal that CH4 emissions can be reduced by uncovering buried waste, while soil and residual organic material enhance CO2 sequestration through microbial activity. Additionally, this review highlights the economic and environmental benefits of material recovery from landfills, including metals and plastics. Overall, this work emphasizes landfill mining as a sustainable strategy for improving waste management practices, while contributing to climate change mitigation.