Environmental and Earth Sciences

Abstract: Human hair discarded by salons, barbershops and households is a dispersed keratin-rich resource whose recovery requires more than identifying a technically possible application. This critical narrative review examines published evidence on human hair valorization, with emphasis on textile and related material systems. It connects collection and material variability with preprocessing, demonstrated applications, environmental assessment and social acceptance. Published studies support oil sorption, metal-ion removal, polymer reinforcement and keratin-based insulation, but these routes differ substantially in processing requirements and evidence maturity. Performance measured for selected fibers, synthetic solutions or laboratory composites cannot establish the effectiveness of mixed salon waste under service conditions. Likewise, results for extracted keratin or animal-derived fibers cannot be transferred directly to untreated human hair. The synthesis identifies opportunities for fiber-preserving technical products while showing that chemical extraction and carbonization require separate environmental justification. Functional equivalence, processing inventories, durability, contaminant management and end-of-life scenarios are essential to substantiate sustainability claims. Transparent collection arrangements and product-specific acceptance studies are equally necessary. Human hair valorization is best pursued through application-specific pilots that verify material performance and net environmental benefit before wider implementation.

Abstract: Dairy whey is an agro-industrial by-product with potential for agricultural nutrient recycling. This study evaluated fermented whey-based biofertilizers containing cattle manure, alfalfa, and baker’s yeast for lettuce (Lactuca sativa L.) production under semiarid conditions in Mexico. Three formulations containing 2.5, 5.0, or 7.5 L of whey were characterized and assessed through a germination bioassay and two 35-day field cultivation cycles. Increasing whey incorporation was associated with higher organic matter and nutrient concentrations, as well as greater electrical conductivity. Seed germination remained high (93.33–96.00%), without significant treatment differences; however, root and shoot lengths were lower than in the water control. Under field conditions, the intermediate formulation (T2; 5.0 L whey) supported strong vegetative development and produced fresh biomass statistically comparable to T3 in both cycles. T2 also showed the highest phosphorus concentration in plant tissue. Soil responses varied by property, with significant treatment effects on changes in pH, electrical conductivity, available phosphorus, and exchangeable potassium, but not on organic matter, total nitrogen, or moisture. These findings identify T2 as a promising formulation for further evaluation, while highlighting the need to monitor seedling growth and soil salinity during repeated applications.

Abstract: Landfills emit biogenic CH₄ with which green H₂ can be produced. However, in developing countries, its territorial potential is unknown. This study presents the first site-resolved national assessment of that potential, with cost and carbon intensity, in Colombia. The 248 disposal sites active in 2024 were analyzed. The CH₄ emissions were estimated with a first-order decay model according to the recommendations of the Intergovernmental Panel on Climate Change (IPCC) and the United States Environmental Protection Agency (US EPA). Catalytic reforming and electrolysis projects were evaluated, with Monte Carlo propagation. Through reforming, production was estimated at 76\( kt_{H_{2}} \)/yr if these sites keep receiving waste, and at 46\( kt_{H_{2}} \)/yr if they close when the current licenses expire, whereas through electrolysis, production was estimated at up to 23\( kt_{H_{2}} \)/yr. The estimates indicated that 90% of the national potential is concentrated in 30 landfills, and that 67% of the H₂ via reforming (23-89%) costs less than 3USD/\( kt_{H_{2}} \). The CH₄ slip proved decisive for the carbon intensity, 0.74\( kg_{CO_2}e \)/\( kt_{H_{2}} \) for reforming and 2.9\( kg_{CO_2}e \)/\( kt_{H_{2}} \) for electrolysis. Capturing the biogenic CO₂ generated in reforming would reduce its carbon intensity to -4.1\( kg_{CO_2}e \)/\( kt_{H_{2}} \), provided that the transport and storage of CO₂ exist.

Abstract: Industrial-residue valorisation through polymer-composite manufacturing can reduce reliance on virgin resources, yet the environmental safety of such materials is rarely evaluated beyond conventional physicochemical characterisation. This study provides a novel, integrated assessment of a waste-derived phenol–formaldehyde/glass-fibre composite by combining pH-dependent leaching analysis with a multispecies ecotoxicological test battery. The composite contained post-production glass fibres, paper flakes, and viscose fibres bound with phenol–formaldehyde resin. Under near-neutral extraction conditions, most analysed metals and metalloids showed limited release. In contrast, acidic conditions substantially increased the mobilisation of Ba, Cr, Zn, Cu, and Pb, while the phenol index increased approximately 28-fold, from 0.25 ± 0.06 to 6.9 ± 1.7 mg L⁻¹. Biological responses differed markedly among taxa. Hordeum vulgare and Eisenia andrei showed limited short-term effects, whereas the marine diatom Skeletonema marinoi exhibited pronounced concentration- and time-related inhibition, with no cells detected after three days of exposure to the highest extract loading. The Aliivibrio fischeri assay also revealed concentration-dependent acute toxicity, with the strongest effects observed during the initial exposure period. The pronounced algal response could not be fully explained by the targeted chemical analyses, indicating a possible contribution of unidentified leachable constituents or mixture effects. The novelty of this study lies in demonstrating that technical functionality, waste diversion, and low concentrations of selected regulated contaminants do not alone ensure the environmental safety of waste-derived polymer composites. Integrating stress-condition leaching with sensitive biological endpoints offers a practical framework for safe-by-design formulation, application selection, and end-of-life management. Further studies should address material ageing, repeated leaching, particle release, and non-target identification of bioactive constituents.

Abstract: Composting recycles organic waste cheaply, but the product often fails fertiliser quality standards. Biochar improves both the process and the product, yet the ecotoxicological consequences of returning compost-derived biochar to composting are poorly understood. Mature but off-specification compost was pyrolysed at 550 °C, and the resulting biochar (CBC) was added at 0, 3, 6 and 9% of dry matter to pilot-scale piles of green waste and sewage sludge (9:1). After 39 days, the composts were analysed for biological stability (AT4), nutrients, heavy metals and leachate ions and tested with the Phytotoxkit (Triticum aestivum, Sinapis alba, Pisum sativum) and Ostracodtoxkit (Heterocypris incongruens) assays. CBC increased K, Mn, Mg and Cu, reduced Ca and slightly increased Cr and Pb; all metals remained below regulatory limits. Only CBC9 met the AT4 stability benchmark, yet it produced the strongest biological response (72.5% shoot inhibition in wheat; 58.7% ostracod growth inhibition). K and Mn correlated most strongly with phytotoxicity but acted as markers of biochar loading; nitrite accumulation and rising leachate salinity were the more probable drivers, whereas heavy metals and ammonium were not. Approximately 3% CBC balanced compost improvement against ecological safety, and composts meeting chemical and stability criteria may still be ecotoxic.

Abstract: Coal fly ash and bottom ash are by-products of lignite combustion in the thermal power plant REK Bitola in North Macedonia, representing a significant environmental challenge as well as a promising secondary resource. This study presents a comprehensive quantitative and qualitative analysis of these ashes, focusing on their physicochemical characteristics and potential for the recovery of critical and strategic raw materials, including rare earth elements. The chemical composition reveals that the ashes are silicate- rich (≈50 %) with lower alumina levels of about 19-20 %, and solid amounts of ferric oxide (12-15 %). Regarding qualitative and economic recovery potential, the biggest promise lies in gallium (30-35 mg kg⁻¹), and side-streams of manganese (1100-5038 mg kg⁻¹), cerium (147-153 mg kg⁻¹) and an REE mixed concentrate. On the quantitative side, the in-place ash inventory at the REK Bitola landfill was estimated using a Digital Elevation Model-based screening workflow in Google Earth Engine. The geometric volume was estimated at 106.8 million m³ and should be considered a Tier-1 screening estimate. The resulting quantitative and qualitative properties are particularly relevant for key stakeholders, including the research community, industry actors, and potential investors, as they highlight the potential for sustainable recovery of valuable and rare metals from this secondary raw material.

Abstract: Municipal solid waste management (MSWM) remains a major environmental and public health challenge in rapidly urbanising cities in sub-Saharan Africa. This study provides a comprehensive analysis of MSWM in Luanda, Angola, focusing on institutional, regulatory, and operational dimensions across the waste management chain. The analysis is based on secondary data from official, technical, and academic sources covering waste generation and composition, pre-collection, collection and transport, recycling, final disposal, and governance. Luanda is also compared with Windhoek (Namibia), Cape Town (South Africa), and Kigali (Rwanda), which have more structured MSWM systems. The results indicate that Luanda generates approximately 2.85 million tonnes of municipal solid waste annually, while collection services reach around 70% of the population. Major deficiencies in pre-collection, infrastructure, and service coverage contribute to widespread uncontrolled dumping, burning, and burial of waste. Recycling remains limited and is largely driven by informal waste pickers. Key challenges include institutional fragmentation, insufficient infrastructure, weak policy implementation, and low public awareness. The study identifies opportunities for urban reorganisation, investment in treatment infrastructure, waste picker inclusion, environmental education, and institutional decentralisation.

Abstract: Municipal solid waste (MSW) pyrolysis is a promising route for recovering energy from non-recyclable fractions while reducing landfill volumes, yet most previous studies address waste characterization, kinetics, process simulation, and economic feasibility separately. This study integrates all four dimensions for representative MSW fractions from Guatemala City, combining laboratory-scale slow-pyrolysis experiments, Arrhenius-based kinetic modelling, industrial-scale process simulation, and a discounted-cash-flow economic evaluation, with the resulting kinetic and multivariable yield models cross-validated against independent literature data from the Central American region. Plastic fractions produced the highest bio-oil yields and calorific values, approaching those of fossil fuels, while organic and lignocellulosic fractions favored biochar formation. Multivariable regression models for prediction of biofuel yield and calorific value in relation to different chemical constituents of feedstock have produced prediction errors within +/-10%. Presence of chlorine and sulfur in co-plasticized materials restricts utilization of bio-oil in combustion engines. Process Simulation has shown that integrating bio-oil refinery into the petrochemical industry is feasible. However, the economic analysis indicated that project viability depends on the successful integration of waste-treatment services with revenues generated from biofuels and energy recovery. These integrated results confirm the technical and economic viability of pyrolysis as a circular-economy waste management strategy for Central American cities, provided the business model combines a waste-treatment-service component with energy recovery.

Abstract: Motor parks are high-activity urban environments where intensive passenger movement, transport operations, and waste generation intersect, yet quantitative evidence linking operational intensity with sanitation and waste-management conditions in Nigerian transport hubs remains limited. Understanding these interactions is necessary for developing targeted environmental health interventions. This study quantified structural and operational characteristics, waste-storage and disposal practices, policy perceptions, spatial differences in operational activity, and passenger utilisation intensity across six selected motor parks in Ilorin metropolis, Nigeria. A cross-sectional observational survey was conducted across six purposively selected motor parks representing public and private ownership structures. Facility-level data on establishment year, fleet size, daily passenger throughput, and passenger-per-vehicle ratio were collected. Among 72 surveyed participants, 36 respondents completed waste-management and policy assessment sections. Descriptive statistics, Wilson confidence intervals, chi-square goodness-of-fit tests, exact binomial testing, and facility-level comparative analyses were performed. Public parks had greater operational capacity than private parks, with mean fleet sizes of 45.0 ± 10.8 and 22.5 ± 3.5 vehicles, respectively, while private parks recorded higher passenger utilisation intensity (4.90 ± 0.14 versus 3.73 ± 0.43 passengers/vehicle/day). Fleet size strongly correlated with daily passenger throughput (Pearson r = 0.974; P = 0.001). Small waste bins were the predominant storage modality (22/36; 61.1%), followed by waste drums (12/36; 33.3%; χ² = 16.667; P < 0.001). Private waste collectors accounted for most disposal arrangements (33/36; 91.7%), and weekly evacuation was most common (28/36; 77.8%). Disposal costs of ≥₦5,000/month were reported by 27/36 respondents (75.0%; χ² = 15.44; P = 0.0015). Monthly sanitation policy ratings were favourable (31/36; 86.1%; P = 0.0014), whereas waste-commercialisation perceptions did not differ from a 50:50 distribution (P = 0.868). Ilorin South recorded the highest aggregate activity (85 vehicles; 330 passengers/day), and passenger utilisation intensity ranged from 3.33 to 5.00 passengers/vehicle/day. Motor parks exhibit substantial variation in operational pressure and sanitation requirements. Integrating transport activity indicators into sanitation planning, strengthening waste-service partnerships, and promoting resource-recovery approaches are recommended. Improved sanitation management in motor parks may reduce environmental exposure risks among passengers, transport workers, and surrounding communities while supporting healthier and more sustainable urban environments.

Abstract: Non-contaminated plastic waste from healthcare facilities is largely non-infectious and rich in recoverable polymers, yet it is routinely incinerated for lack of an automated sorting process suited to the clinical setting. This paper presents a sensor fusion system design and a comparative hyperspectral classification methodology for that stream. Near-infrared hyperspectral imaging, an RGB line-scan camera, and an inductive metal sensor are integrated on a collaborative robot platform, combining polymer-type identification, visual object detection, and metal discrimination in a late-fusion pipeline. Two hyperspectral classification strategies are specified and compared across labeling cost, robustness, interpretability, and stage of system maturity: reference-spectra distance matching, which needs no labeled training data, and supervised machine learning, which gains robustness as the labeled dataset grows. The two are ordered as successive development phases, the first bootstrapping the second. A throughput and spectral analysis establishes the sensor specification required for production line speeds, which the pipeline architecture accommodates without change to the classification methodology. The regulatory scope of the recoverable fraction under German waste legislation is treated as an explicit design input, determining the material classes targeted and the open-set rejection behavior required of the classifiers. Open design parameters and a validation pathway are identified.

Abstract: Primary teachers shape early environmental understanding, yet their formal preparation in waste management remains poorly documented. This study audited all nine Greek public undergraduate primary-teacher programmes. Official study guides and course descriptions available by 29 August 2026 were screened for explicit content on solid waste, wastewater, sludge, and biosolids. Generic environmental references and undifferentiated mentions of waste were excluded unless a target domain or qualifying management operation was explicit. Five programmes (55.6%) contained at least one relevant course. Solid waste appeared in four programmes (44.4%), wastewater in three (33.3%), and sludge or biosolids in none. Of the five retained courses, one was compulsory, one compulsory-choice, and three elective; only one programme (11.1%) guaranteed relevant exposure. Four courses provided substantive coverage and one incidental exposure. A full independent audit produced agreement on 40 of 45 programme-level binary decisions (88.9%; pooled Cohen's kappa = 0.72). Discrepancies were resolved by consensus using predefined rules and original sources. The documented curriculum therefore provides fragmented and uneven preparation, with compulsory exposure rare and no explicit coverage of treatment residuals. The findings support consideration of a minimum learning entitlement integrating the waste hierarchy, wastewater treatment, treatment residuals, resource recovery, risk communication, and primary-school pedagogy.

Abstract: Improper management of domestic organic solid waste (DOSW) poses an environmental challenge, and composting offers a low-cost valorization alternative, though the effect of substrate composition and microbial inoculation on process performance remains unclear. This study evaluated the effect of substrate composition and lactic acid bacteria inoculation on the dynamics and physicochemical and microbiological quality of compost from DOSW via horizontal composting, and its agronomic performance in lettuce (Lactuca sativa L.). A completely randomized design with four treatments (T0: 100% DOSW; T1: 50% DOSW + 50% rice husk + bacteria; T2: 75% DOSW + 25% rice husk + bacteria; T3: 100% DOSW + bacteria) and three replicates ran 103 days, monitoring temperature, moisture, pH, color, and odor; final compost was characterized per NTC 5167 and evaluated for effects on lettuce growth and soil. No treatment reached a thermophilic phase, though rice husk improved porosity and reduced odor persistence. All composts were free of Salmonella spp. and enterobacteria, meeting safety criteria. T2 showed the best balance of stability, microbiological activity, and nutritional quality, while inoculation did not improve lettuce yield, with T0 yielding the highest biomass. Findings confirm horizontal composting of DOSW with structuring materials is a viable, safe, low-cost alternative.

Abstract: Food waste in the restaurant sectors represents a critical global challenge with significant environmental and economic impacts. Addressing this issue requires a transition toward automated and intelligent waste management systems within a circular economy framework. However, the deployment of deep learning-based solutions is largely limited by data scarcity, class imbalance, and the high cost of pixel-level annotation. In this paper, we propose a data-centric deep learning framework for food waste classification and semantic segmentation. Instead of relying solely on architectural modifications, our approach improves model performance by integrating a stability-driven study within a U-Net/VAE framework, where CLIP-in-the-loop supervision and performance feedback (IoU and Dice scores) are incorporated to guide and refine the learning process. The proposed framework combines classical augmentation techniques, annotation-free compositional fusion, and CLIP-guided Stable Diffusion models (with CLIP supervision set to 0.3 in most configurations to enhance semantic alignment and visual consistency) to generate realistic and balanced synthetic food waste scenes.The suggested framework creates realistic and balanced synthetic food waste scenes by combining traditional augmentation techniques, annotation-free compositional fusion, and CLIP-guided Stable Diffusion models (with CLIP supervision set to 0.3 in most configurations to improve semantic alignment and visual consistency).We provide structured pseudo-labels that are aligned with the synthesised compositions in order to further enhance supervision quality. This allows for the generation of scale datasets without the need for manual annotation. The efficiency of the suggested data-centric approach is confirmed by experimental findings on the FoodSeg103 dataset, which show strong improved performance with IoU and DICE values between 0.70 and 0.90 across the majority of new classes.By reintroducing the Dice score into the loss function and integrating CLIP into the prompt refinement loop, the proposed method ensures training stability while offering a scalable and useful solution for intelligent waste sorting and supporting the development of automated decision systems to be integrated in advanced computer vision–based sustainable food waste management.

Abstract: The objective of this study was to evaluate the degree of sludge stabilization in septic tanks by assessing the mineralization of retained sludge at different retention times. Under normal operating conditions, sludge remains inside septic tanks for extended periods, typically ranging from 8 months to 2 years. From a process engineering perspective, septic tanks operate as semi-continuous systems, in which wastewater enters continuously while sludge is removed intermittently. To evaluate sludge stabilization, sludge samples were collected from four full-scale septic tanks operating under real field conditions. The quality of the sludge is determined by the volatile fraction; the lower this value, the higher the physicochemical quality of the sludge, the volatile fraction is equivalent to the percentage of volatile suspended solids, which is evaluated by determining the ratio between volatile suspended solids (VSS) and total suspended solids (TSS). A lower VSS/TSS ratio indicates greater sludge stabilization. The results obtained allow for the evaluation of sludge quality and stabilization under different operating conditions y and the endogenous constant in various scenarios. Finally, it is confirmed that septic tanks operate as a digester, reducing volatile material, and that their endogenous constant is below that of traditional digesters, which explains the residence times of the biomass and their respective periods of discharge and evacuation of the sludge.

Abstract: The olive industry is experiencing significant growth, held back only by the environmental and management issues that its by-products can cause. The two most polluting effluents produced are a new aqueous phase or ‘alpechín’ in the olive oil industry, and brine in the table olive ones. The high organic and phytotoxic load of both, together with the conductivity of the brines, makes their reuse difficult and poses a real technological challenge due to the environmental problems they are causing. This study demonstrates that the application of thermo-malaxation followed by three-phase centrifugation allows the removal of most of the most active phenolics, including hydroxytyrosol, 3,4-dihydroxyphenylglycol and tyrosol—from the alperujo in a 30%, yielding a partially detoxified solid phase and a liquid phase rich in the most active phenolics. Furthermore, the application of an industrial chromatographic process enables the removal of between 50% and 75% of the phenolic load from the liquid fraction of the aforementioned system, as well as from the brines of the table olive industry. The high antioxidant activity of the extracted phenolics has also been verified through in vitro assays.

Abstract: Solid waste management (SWM) is an important public health and environmental problem in the cities of developing countries. This is a systematic literature review (SLR) that synthesizes evidence of health and environment effects from the improper waste disposal with particular reference to Gaborone City, Botswana. Scopus, Web of Science, Google Scholar and PubMed were searched, resulting in 2,978 records that were subjected to PRISMA-guided screening and quality assessment, leading to 60 key studies. Although there is a known lack of Botswana specific data, there is also evidence that open dumping and open burning along with poor collection services result in respiratory disease, gastrointestinal infections, vector borne disease and multi-compartmental environmental contamination. Electronic waste is particularly dangerous and represents a fast-growing waste stream which globally has 75-78% that is inadequately managed. In Gaborone, risks are exacerbated by policy gaps, institutional fragmentation, and poor implementation of laws. This paper provides evidence-based recommendations that align with Botswana Vision 2036, the African Union Agenda 2063, and the UN Sustainable Development Goals (SDGs), specifically aimed at the Ministry of Health, the Ministry of Environmental Protection and Gaborone City Council for consideration in the context of the municipal SWM scoping review of Botswana. Finally, the study highlights the pressing need for enhanced solid waste organization and health-oriented policies in Sub-Saharan Africa (SSA).

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The macro algae Sargassum spp. reaching the beaches of Quintana Roo, Mexico, has represented an environmental problem since 2011 due to its massive influx and the lack of adequate instruments for its management, treatment and final disposal. Physicochemical parameters of the macroalgae were evaluated in samples collected from three beaches in Quintana Roo during 2020, 2023 and 2025. Total and inorganic arsenic concentrations were determined using an alternative method based on hydride generation atomic absorption spectrometry coupled with an automated cryotrapping system and flow injection analysis system (HG-AAS-AC-FIAS). From the perspective of Mexican waste regulations, sargassum is classified as Special Management Waste (SMW) and is considered non-hazardous waste since arsenic concentrations in aqueous phase did not exceed the maximum permitted limit of 5 mg/L established by NOM-052-SEMARNAT-2005. Therefore, its management should comply with NOM-061-SEMARNAT-2011 that deals with SMW. However, as a potential raw material, sargassum contained total arsenic concentrations of 22.272 ± 0.598 mg/kg dw (2020), 12.46 ± 0.5 mg/kg dw (2023) and 170.67 ± 13.614 mg/kg dw (2025). Inorganic arsenic was detected in 2023 and 2025 samples at 10.005 ± 0.042 mg/kg dw and 68.63 ± 0.106 mg/kg dw, respectively. These findings highlight the need for specific management, treatment, disposal and clear guidelines for its use as a raw material for sargassum valorization.

Abstract: This study evaluates the potential of solid digestate as a feedstock for granulated organo-mineral fertilizers (OMF). The aim was to improve nutrient density, safety, and soil conditioning properties while supporting circular bioeconomy principles. Digestate was enriched with ammonium sulfate, monoammonium phosphate, and potassium chloride to produce OMF. The granules were analyzed for nutrient content, heavy metals, and functional group stabilization (FTIR). Soil incubation tests assessed the cation exchange capacity (CEC), while spring barley pot experiments evaluated biomass production and nutrient uptake. OMF granules achieved nutrient levels of N = 5.0%, P₂O₅ = 5.9%, and K₂O = 4.7%, with dry matter of 95.9% and ash content of 32.4%. Heavy metals (Cd < 0.5, Pb < 5, As < 1.0 mg/kg) were well below EU safety thresholds. Compared to digestate pellets (C:N ≈20:1), OMF (C:N ≈7.8:1) showed faster mineralization. Soil incubation revealed increased CEC from 26.1 to 32.1 cmol(+)/kg. Barley biomass rose by 6.8–9.6%, with P and K accumulation strongly correlated with growth (r = 0.960 and r = 0.828). Uptake efficiencies reached 14.6% for P₂O₅ and 86.9% for K₂O. Digestate valorization through organo-mineral granulation provides a safe and effective fertilizer pathway that enhances soil fertility, nutrient efficiency, and crop performance, while contributing to sustainable circular agriculture.

Abstract: Between 1943 and 1989, the Hanford Nuclear Site produced weapons-grade plutonium and accumulated 212,000 cubic meters of mixed radioactive and hazardous chemical waste, stored in 177 aging underground tanks. It is estimated that 90% of this waste is “Low Activity Waste” after the cesium, strontium, and transuranics are removed. In late 2025, the Direct Feed Low Activity Waste facility began vitrification, which involves mixing liquid waste with molten glass at 1150 °C to destroy hazardous organic chemicals, at an average rate of 15 metric tons per day. Maintaining heat in the two 300-ton melters requires about 200,000 megawatt-hours of electricity each year. Over 40 years, this electricity use results in about 3,000,000 tonnes of carbon dioxide emissions. To mitigate this carbon footprint, a significant portion of the waste could be “grouted” with a mixture of Portland cement, granulated slag, fly ash, and batch-specific chemicals. Vitrifying LAW has a carbon footprint of about 32 tCO₂e per cubic meter (m³), whereas grouting LAW and shipping it out-of-state by truck involves about 6 tCO₂e/m³, and shipping it by rail involves about 2.5 tCO2e/m3. Adding a rail spur to a grouting facility is key to Hanford’s net-zero approach.

Abstract: The rapid global expansion of photovoltaic (PV) systems, driven by rising energy demand, is expected to generate substantial module waste at end-of-life, with global PV waste projected to exceed 4 million tonnes by 2030, 50 million by 2040, and 200 million tonnes by 2050. Based on 102 publications identified through Scopus, Web of Science, Google Scholar, and IEEE Xplore databases, this review provides a comparative, literature-based assessment of recycling, second-life applications, and disposal as end-of-life (EoL) management strategies for PV modules, examining the relationship between module structure, waste management pathways, material recovery potential, and the technical and economic limitations of current practices. Recycling offers clear environmental benefits but remains economically constrained in many scenarios by high process costs and the complexity of separating laminated module structures. Second-life application emerges as a complementary strategy, delaying the premature entry of modules retaining residual functionality into the waste stream and enhancing resource efficiency. Nevertheless, landfilling continues to account for the majority of global PV waste despite the availability of more sustainable alternatives, revealing a marked gap between technical potential and field-level practice. Overall, no single approach is sufficient; effective PV waste management requires an integrated strategy combining recycling, second-life applications, and disposal in line with circular economy principles.