This study develops a technical–economic model to support planning for second-life reuse and end-of-life management of residential PV modules in Brazil. The model integrates module degradation, residential electricity-demand dynamics, and consumer utility-based replacement decisions to identify temporal milestones at which modules remain technically functional but become vulnerable to premature replacement. By combining technical performance with consumer behavior, the model captures critical transition points between continued operation, replacement, and reuse pathways. Simulation results indicate that premature PV waste generation is highly sensitive to household consumption growth. Under early-growth demand profiles, users reach the attention and break-even milestones at 11.7 and 13.7 years, respectively, whereas under stable-growth profiles, these thresholds occur only at 27.6 and 29.9 years. This difference substantially increases the period during which modules may be replaced before reaching the estimated technical end-of-functional-life threshold of 29.6 years, demonstrating how demand-side dynamics can accelerate waste generation independently of module degradation. The findings indicate that integrating technical and economic criteria into planning decisions may help identify opportunities to extend module service life and reduce avoidable PV waste. The proposed model contributes to the waste-management literature by providing a scalable decision-support basis for reuse assessment, reverse logistics planning, recycling prioritization, and evidence-based policy development. More broadly, it may contribute to strategies that connect low-carbon energy transitions with circular economy principles and the United Nations Sustainable Development Goals (SDGs).
Polyethylene terephthalate (PET) and polystyrene (PS) nanoplastics are major aquatic contaminants due to their high persistence, mobility, and potential ecological impacts. In this study, PET–NPs and PS–NPs were prepared by nanoprecipitation, and the adsorption of both types of nanoplastics by graphene oxide–chitosan (GO–CS), graphene oxide–microcrystalline cellulose 50µm (GO–MCC50µm), and graphene oxide–microcrystalline cellulose 90µm (GO–MCC90µm) composites was systematically investigated. The structural and physical properties of the materials were characterized using transmission electron microscopy (TEM), pHpzc analysis, Dynamic Light Scattering (DLS), zeta potential, and X-ray photoelectron spectroscopy (XPS). Batch adsorption experiments evaluated the effects of pH, contact time, initial concentration, and temperature on adsorption efficiency, while the adsorption mechanism was analyzed through kinetic, isotherm, and thermodynamic studies. The maximum Langmuir adsorption capacities for PS–NPs were 13.60, 12.59, and 11.19 mg·g−1 for GO–CS, GO–MCC50µm, and GO–MCC90µm composites, respectively. The maximum adsorption capacities for PET–NPs were 56.17, 33.33, and 23.20 mg·g−1 for GO–CS, GO–MCC50µm, and GO–MCC90µm composites, respectively. This study provides new insights into the effects of adsorbent surface chemistry, particle size, and nanoplastic morphology on adsorption processes, highlighting graphene oxide–polysaccharide composites as promising eco-friendly materials for nanoplastic removal from aqueous media.
This study explores the relationship between Artificial Intelligence (AI) and net-zero carbon buildings (NZCBs) and net-zero energy buildings (NZEBs) over the last decade. A thematic evolution has been observed in this research area, shifting from conventional optimization towards more advanced digital, intelligent, and decarbonized infrastructure. Co-occurrence, clustering, thematic evolution, network, and visualization justify this science mapping analysis at regular intervals (2015–2018, 2019–2022, and 2023–2026). Digital twins (DTs) have been identified as the dominant theme in strategic analysis, integrating Building Information Modeling (BIM), sensors, communication networks, and AI algorithms. In contrast, there has been the emergence of GIS as a complementary platform for extending AI applications beyond individual buildings to neighborhood, city, and regional scales through carbon mapping, life-cycle assessment, energy storage planning, and spatial decision-making. The analysis highlights AI as supporting technology rather than an isolated research theme, managing building information through digital twins and facilitating urban-scale decarbonization through GIS. The novelty of this study lies in proposing a dual framework that aligns digital twins and GIS as complementary implementation platforms for connecting AI with net-zero building objectives. The developed framework provides valuable insights into the intellectual structures creating intelligent, energy-efficient, and carbon-neutral built environments.
Nitrogen (N) and phosphorus (P) influx into receiving water bodies leads to cultural eutrophication and, therefore, poses a major environmental challenge. Consequently, increasingly stringent discharge limits have been established, necessitating advanced wastewater treatment methods. In addition, phosphorus is a finite resource, with current reserves projected to last less than a century. The principles of the circular economy therefore emphasize not only the removal of N and P from wastewater, but also their recovery and reuse as fertilizers. This article presents two strong-base anion-exchangers impregnated with zirconium oxide (ZrO2) nanoparticles to create the following: (1) a phosphorus-selective resin (Hybrid Anion Exchanger with ZrO2 (HAIX-Zr)), with a Zr loading of 2.5–3% (m/m) and an ion-exchange capacity (IEC) of ≈35 mg PO43− − P/g resin, and (2) a resin selective for both phosphorus and nitrate (Nitrate-Selective Resin with ZrO2 (NSR-Zr)), with a Zr loading of 1.5–2% (m/m), a simultaneous phosphate IEC of ≈41.3 mg PO43− − P/g resin, and a nitrate IEC of ≈41.3 mg NO3− − N/g resin. When loaded in a fixed-bed column, HAIX-Zr can treat > 300 Bed Volumes (BV) of wastewater to below the phosphate detection limit of 0.02 mg/L when the initial phosphate–phosphorus concentration is ≈11.0 mg/L and the two most common competing anions, Cl− and SO42−, are present at ≈225 mg/L and ≈160 mg/L, respectively. Regeneration of the exhausted HAIX-Zr column with a 2% NaCl + 2% NaOH solution resulted in >95% P recovery, which can be processed to generate MgNH4PO4 (struvite), a slow-release fertilizer. A fixed-bed NSR-Zr column can treat ≈150 BV of wastewater to below the phosphate detection limit of 0.02 mg/L and nitrate detection limit of 0.05 mg/L when the initial phosphate–phosphorus concentration is 31 mg/L, the nitrate–nitrogen concentration is 12 mg/L, and the competing anions Cl− and SO42− are present at ≈175 mg/L and ≈155 mg/L, respectively. Regeneration of the exhausted NSR-Zr column with 2% KOH solution resulted in >92% recovery of nitrogen and phosphorus in a solution rich in nitrogen, phosphorus, and potassium, the essential ingredients of a fertilizer.
Large volumes of solid waste are produced by the winemaking sector, which could be utilised as adsorbents to retain contaminants, providing a beneficial approach in terms of economic recovery and sustainability. The adsorption of nitrate onto biochar produced from grape pomace has not received enough attention, even though biochar-based materials have been thoroughly studied for water treatment applications. This study aims to fill the knowledge gap by assessing a low-cost mildly carbonized biochar derived from winery residues for nitrate retention and optimising the nitrate retention procedures by comprehensive physicochemical characterisation. The mildly carbonized biochar prepared from grape pomace collected from the Dealu Mare wine region (Romania) was characterized using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM–EDX), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), and thermogravimetric and derivative thermogravimetric (TGA/DTG) analyses. Results revealed a structure enriched with oxygen-containing functional groups that promote nitrate retention through combined physical adsorption and electrostatic interactions. Surface analyses after adsorption confirmed the successful immobilization of nitrate species on the biochar matrix. The adsorption performance was improved by Response Surface Methodology (RSM) method using a Central Composite Design (CCD), studying the influences of the following parameters: solution pH, adsorbent weight, nitrate concentration and time. Among all variables, pH was identified as the dominant factor controlling adsorption efficiency, reflecting the key role of surface charge interactions. The optimized conditions (175 mg/L nitrate, pH 6, 0.3 g adsorbent dosage, and 94 min contact time) resulted in a maximum nitrate removal efficiency (RE) of 86.69%, while the predictive model exhibited excellent accuracy (R2adj = 0.985). The findings demonstrate that mildly carbonized grape pomace biochar can achieve competitive nitrate removal without chemical surface modification, offering a more sustainable and economically attractive alternative to conventionally biochars. The research highlights that selecting feedstock and utilizing intrinsic surface functionality can create efficient nitrate adsorbents from agro-industrial residues.
Biorefineries that convert the organic fraction of municipal solid waste (OFMSW) into advanced biofuels can integrate waste management with renewable energy production. However, their environmental performance remains insufficiently characterised owing to a scarcity of life cycle assessment (LCA) studies based on real operational data. This study presents a gate-to-gate LCA of a demonstration biorefinery processing source-separated food waste into bio-oils, bioethanol, and biogas. The ReCiPe 2016 Midpoint (H) method was applied across 18 impact categories, with system expansion crediting the displacement of rapeseed oil, maize-derived ethanol, and marginal biogas-derived electricity. The net global warming potential (GWP) was 68.5 kg CO2 eq per tonne of wet OFMSW (69% reduction from gross), placing the biorefinery 83–93% below landfilling, 63% below incineration with CHP, and above standalone anaerobic digestion systems that lack the energy-intensive drying and enzymatic hydrolysis steps of the present configuration. Bio-oil and bioethanol achieved net-negative GWP per kilogram of product (−0.89 and −0.66 kg CO2 eq, respectively), whilst eleven of eighteen categories achieved net savings under system expansion. Enzyme production dominated the bioethanol environmental profile (37–94% across categories), whilst drying dominated bio-oil (46–93%). Monte Carlo simulation confirmed that the sign of the net impact stayed unchanged across the entire 95% confidence interval (the interval did not span zero) for 17 of 18 categories.
Access to safe drinking water remains a global challenge, particularly in decentralized and low-resource settings where conventional treatment technologies may be economically or operationally impractical. Combining low-energy hydraulic flocculation systems with biodegradable natural coagulants represents a promising strategy for sustainable water treatment. This study investigated the influence of hydraulic retention time (HRT) on the clarification performance of aluminum sulfate, Moringa oleifera, and Aloe vera in continuous-flow helically coiled tube flocculators (HCTFs). Four HRTs (1.71–6.84 min) were obtained by varying reactor length while maintaining a constant flow rate of 0.5 L/min. Synthetic water with an initial turbidity of approximately 100 NTU was treated, and clarification performance was evaluated by residual turbidity and turbidity removal efficiency. Two-way ANOVA revealed significant effects of HRT and coagulant type, as well as a significant interaction between these factors (p < 0.001), indicating that the influence of HRT depended on the dominant coagulation mechanism. Aluminum sulfate maintained consistently high turbidity removal efficiencies (96.3–98.1%) regardless of HRT. In contrast, Moringa oleifera achieved the highest clarification efficiency (99.5%) and a final turbidity of 0.49 NTU at the longest HRT, whereas Aloe vera exhibited the greatest hydraulic sensitivity, with turbidity removal increasing from 78.9% to 96.1% as HRT increased. The results demonstrate that HRT should be selected according to the dominant coagulation mechanism of the coagulant rather than adopted as a fixed design parameter. This mechanism-based approach provides a rational basis for designing and optimizing continuous-flow flocculators and supports the development of compact, efficient, and sustainable decentralized water treatment systems.
This study investigates the thermal, economic, and environmental performance of heat recovery ventilators (HRVs) in hot climates, which has not been thoroughly investigated because standards and applications to date have focused primarily on cold climates. Experimental testing was conducted at airflow rates of 200–350 m3/h and outdoor air temperatures of 30–45 °C, representing typical summer conditions. HRV thermal performance was evaluated by measuring airflow rates and temperatures and then determining the heat transfer rates between the two air streams. Effectiveness increased by 3.9% when the supply inlet temperature increased from 30 to 45 °C, but decreased by 9.3% when airflow increased from 200 to 350 m3/h. The overall heat transfer coefficient remained nearly constant with increasing supply temperature but increased by approximately 37% as airflow increased. The highest recovery efficiency ratio (RER), defined as the ratio of supply air pre-cooling capacity to HRV power consumption, was 26.6 Btu/W.hr at 300 m3/h and 45 °C. Economic analysis based on the reduction in ventilation cooling load yielded payback periods ranging from 2.7 to 13.3 years. Annual CO2 emission reductions ranged from 151 to 776 kg/year per HRV unit, demonstrating the environmental benefits of HRV systems in hot climates.
Poly(lactic acid) (PLA) is a renewable and biodegradable polymer that has attracted considerable attention for sustainable packaging applications. However, its inherent brittleness limits its use in flexible films. In this study, PLA/poly(vinyl alcohol) (PVA) blend films were prepared by a single-solvent-casting rout at PLA/PVA weight ratios of 80/20, 70/30, 60/40, and 50/50 to investigate the influence of composition on their thermal, chemical, morphological, mechanical, optical, and water vapor barrier properties. Increasing the PVA content progressively modified the molecular organization of the system, the crystallization ability of the PLA phase and promoting a more homogeneous phase distribution. These structural changes resulted in a transition from a brittle behavior to increasingly ductile films, with the PLA/PVA 50/50 composition exhibiting the most favorable combination of tensile toughness, transparency, and morphological homogeneity, reaching an elongation at break of approximately 60%. In contrast, the increase in the hydrophilic phase led to higher water vapor permeability, highlighting the trade-off between mechanical performance and moisture barrier properties. Overall, the results demonstrate that controlling the PLA/PVA ratio provides an effective strategy for tailoring the morphology and functional properties of solvent-cast PLA/PVA films, contributing to a better understanding of the composition–structure–property relationships in biopolymer blends.
The fastest growing waste stream worldwide is represented by Waste from Electrical and Electronic Equipment (WEEE). One of the main critical issues related to the recovery of such waste is the mixed plastic fraction, which is difficult to sort and can contain flame retardants and additives that pose a risk to human health and the environment. This study aims to validate the possibility of using tribo-electrostatic separator technologies to sort plastic polymers (e.g., PP, PA6, PS and PVC) obtained after a size-reduction operation of WEEE. The experimental study was conducted on a 10 kg/h laboratory-scale pilot plant. Several parameters were analysed during the tribo-charging and electrostatic separation processes, including the rotation speed and residence time of the particles in the tribo-charging device as well as electrode voltage, and the distance between the deflectors and the electrodes in the electrostatic separator. The results show that the tribo-electrostatic separation technologies are promising and efficient for plastic waste recycling. In fact, under specific conditions, it is possible to achieve high recovery rates (>70%) and purity levels (>76%) that allow the reintegration of plastic polymers into the economic cycle as a secondary raw material.
Understanding the carbon emission characteristics of fused filament fabrication (FFF) is important for the development of more sustainable additive manufacturing practices. This study presents a framework for quantifying, modelling, and optimizing the carbon emissions of FFF-printed specimens of carbon-reinforced Polyethylene Terephthalate Glycol (PETG-CF) composite. Carbon emissions were assessed within a cradle-to-gate system boundary by considering material consumption and electrical energy usage during fabrication. The influence of print speed, raster angle, layer height, infill density and infill pattern on carbon emissions were experimentally investigated. Response Surface Methodology (RSM) was utilized to formulate a predictive carbon emission model, while analysis of variance was applied to assess the significance of the process parameters. The findings revealed that infill density, infill pattern, layer height, and raster angle significantly affected carbon emissions, while print speed showed a comparatively lower influence. Contour plot analysis was used to visualize parameter interactions and identify low-emission regions. RSM-based optimization predicted a minimum carbon emission of 0.0732 kgCO2eq at a print speed of 220 mm/s, layer height of 0.12 mm, infill density of 50%, raster angle of 0°, and rectilinear infill pattern. The proposed framework presents a practical strategy for integrating carbon emissions for a sustainable FFF process.
This study evaluates, from energy, exergy, exergo-sustainability, and environmental perspectives, two combined-cycle configurations based on a supercritical CO2 Brayton cycle coupled to an ORC: a simple reheat configuration (S-CO2-ORC) and a recompression-reheat configuration (SRC-CO2-ORC). Both were assessed under two thermal sources: concentrated solar power (CSP) and a hybrid biomass-CSP source using oil palm residues. Sizing was based on the cooling demand of a 130-home residential complex in Barranquilla, estimated at 152 kW through hourly simulation. The SRC-CO2-ORC configuration delivered the best energy performance, reaching 138.38 kW and 55.34% with CSP and up to 157.28 kW and 57.66% under hybrid operation. The highest irreversibilities were concentrated in the solar field and receiver, while the thermal sources contributed more than 85% of the total carbon footprint. The lowest life-cycle impact corresponded to the SRC-CO2-ORC-Solar configuration, at 0.0117 kg CO2-eq/kWh, against 0.0194 kg CO2-eq/kWh for the S-CO2-ORC-Hybrid case. The results confirm the technical feasibility of these configurations for residential applications and reveal a clear trade-off between thermodynamic performance and minimum carbon footprint.
This study proposes a hydrogen-powered industrial ride-on scrubber (IRoS) investigated by using in situ and on-board H2 production. Technological and financial calculations involving conventional liquefied petroleum gas (LPG), an electric battery, and a hydrogen-powered system in IRoS are discussed. Energy consumption, operational costs, financial aspects and environmental impacts are also discussed. Investment payback analyses to replace an LPG machine are discussed. For 10 years, the highest operational costs and downtime costs are of the LPG-powered scrubber (USD ~187k). The two other systems are substantially lower, i.e., ~4% and 7%. CO2 emissions of the three examined scrubbers ranged between 162 and 194, 10 and 13, and 5 and 9 tCO2, respectively. Gravimetric energy density (GED) reveals that the LPG-powered system is ~2× and 10× higher than the battery- and H2-powered systems, respectively. Adequate modulation and control of the produced H2 volume in Al hydrolysis are keys to success in the H2-powered scrubber project. For this purpose, three aspects are important: i. adequate selection of Al-based alloy or mixture powders, ii. the nature and concentration of alkali solution and iii. the quantity of solid (Al-based alloy or mixture powders) per volume of alkali (liquid), designated as S/L ratio.
The rapid global expansion of data center infrastructure has prompted substantial clean technology research on energy, water, and carbon impacts, while the acoustic health dimension of these facilities remains virtually unstudied. Existing occupational and environmental noise assessments rely on A-weighted (dBA) metrics, which apply more than 26 decibels (dB) of attenuation at 63 hertz (Hz) and exceed 50 dB at infrasound frequencies, sharply discounting their sensitivity to infrasound and low-frequency noise (ILFN) generated by data center cooling fans, heating, ventilation, and air conditioning (HVAC) systems, backup generators, and power transformers. This narrative review synthesizes evidence from established ILFN health research alongside the emerging data center acoustics literature, identifying a consequential gap: no published study has measured the ILFN spectrum of an operational data center, nor examined health outcomes in workers or surrounding communities with respect to sub-audible acoustic exposure. Evidence from wind turbine, industrial, and laboratory contexts documents non-auditory ILFN pathways, including sleep disturbance, cardiovascular stress responses, cognitive impairment, and audiovestibular symptoms—effects that operate below the auditory threshold and are substantially undercounted by standard dBA monitoring. A prioritized research agenda is proposed, beginning with G-weighted and flat-response ILFN characterization of operational data centers across at least 1–200 Hz—a prerequisite for evidence-based acoustic design standards and health-protective infrastructure development consistent with clean technology principles.
Power-to-Ammonia-to-Power (P2A2P) systems in hot-arid MENA climates reject waste heat through Recuperated Organic Rankine Cycles (RORCs) whose condensation temperature tracks ambient conditions across annual swings exceeding 35 K. Standard exergoenvironmental assessments evaluate priorities at a single dead-state temperature, an assumption this study terms the Static T0 Fallacy. A four-way advanced exergy decomposition is combined with an off-design model (Stodola’s ellipse, constant-UA scaling) to sweep the dead-state temperature from 5 ∘C to 40 ∘C. At T0=20 ∘C, 95.8% of total exergy destruction is endogenous, confirming weak inter-component coupling. The condenser carries the largest avoidable environmental impact rate (4.02 mPts/h, 74% of the system total). At T0=37.4 ∘C, the recuperator undergoes a priority inversion from destruction-dominated (fb=14.7%) to fully capital-dominated (fb=100%). Ammonia’s wet-fluid thermodynamic coupling eliminates the recuperator’s duty as the condensation temperature approaches the cold-side outlet constraint. The recuperator’s avoidable environmental impact rate drops by 100% relative to the standard assessment, while the condenser’s rises by 49%. This inversion mechanism is fluid-specific: the ammonia recuperator’s endogenous fraction reaches 99.5% at T0=20 ∘C. The toluene recuperator, swept at its own independently optimised operating point, has an endogenous fraction between 59.08% and 82.31% over the same range. For P2A2P installations where the annual ambient swing exceeds 15 K, exergoenvironmental analysis should be performed at both design-season and summer-peak dead-state temperatures, with the summer-peak result governing capital allocation.
Hydrogen-based technologies are widely considered promising pathways for decarbonizing power generation and industrial energy systems; however, their overall sustainability depends strongly on both production routes and conversion efficiencies. This study presents a comparative energy and exergy analysis of hydrogen-based decarbonization pathways under a consistent 1 MW net electrical output boundary, including natural gas combustion (S0), grey hydrogen combustion (S1), grey hydrogen fuel cell (S2), green hydrogen combustion (S3), and green hydrogen fuel cell (S4) systems. The results indicate that combustion-based pathways (S0, S1, and S3) exhibit relatively low energy efficiencies of approximately 30–40% and exergy efficiencies of 25–40%, accompanied by high exergy destruction levels generally exceeding 60%. In contrast, fuel cell-based configurations (S2 and S4) demonstrate improved conversion-stage thermodynamic performance, achieving energy efficiencies of 50–60% and exergy efficiencies of 45–65%, while reducing exergy destruction due to electrochemical conversion and lower irreversibilities. A detailed comparison shows that the natural gas reference system reaches an exergy efficiency of 33.7%, whereas the hydrogen fuel cell system achieves 46.5%, corresponding to approximately 42% lower exergy destruction and about 36% reduced fuel input. From an environmental perspective, the simplified carbon assessment indicates that natural gas combustion generates approximately 577 kg CO2/h. Grey hydrogen pathways remain associated with substantial upstream emissions, generating approximately 857 kg CO2/h for grey hydrogen combustion and 545 kg CO2/h for grey hydrogen fuel cell operation under the 1 MW net electrical output basis. In contrast, green hydrogen-based pathways are assumed to have near-zero direct/upstream operational CO2 emissions under renewable-powered production assumptions. Overall, the findings show that hydrogen use alone does not guarantee decarbonization; rather, both the hydrogen production route and the final conversion technology must be considered to achieve thermodynamically efficient and low-carbon power generation.
Managing polymer waste, primarily polyolefins—low- and high-density polyethylene and polypropylene—is a critical challenge in the transition to a low-carbon, circular economy. Traditional approaches (landfilling and incineration) are inconsistent with sustainable development principles and increasingly stringent extended producer responsibility regulations, while chemical recycling, particularly catalytic pyrolysis, is considered a key technology for returning hydrocarbon feedstocks to the production cycle. This mini-review systematizes and analyzes current advances in the catalytic pyrolysis of polyethylene and polypropylene. An algorithm for selecting a recycling route for polyolefin-containing waste based on its composition, degree of degradation, and the presence of hazardous additives is proposed. Existing and planned industrial projects in the field of chemical recycling of polyolefins are assessed, and challenges and prospects for technology commercialization are outlined. It is demonstrated that catalytic pyrolysis has the potential to become a key element of a circular economy for plastics, ensuring decarbonization and resource conservation with further optimization of catalysts and process flowsheets.
Topics related to renewable and sustainable energy have been addressed by several scientific studies over the last few decades. Nonetheless, it is important to highlight what has already been done by the scientific community and what remains to be done in these fields to provide more insights for stakeholders, including policymakers, researchers, and economic operators. The literature survey showed that there are still gaps to be considered in the literature and novelties to be brought through different approaches, particularly those that take into account the several dimensions of these issues. From this perspective, this research aims to present the dimensions of renewable and sustainable energy explored in scientific documents, benchmarking past and future pathways in these domains. To achieve these objectives, a bibliometric analysis (focusing on scientific maturity) was carried out separately across different dimensions associated with this topic (this is one of the novelties of this study). Additionally, a targeted literature analysis based on bibliometric analysis was done, considering the most relevant documents. This research adopts a broad perspective in order to capture the context of energy transition, clean energy, and low-carbon development. The findings obtained show that the subject of renewable and sustainable energy has several topics and subtopics with different dynamics. Within these subtopics, it is worth mentioning the following: solar and wind energy are almost in the saturation phase (85.1% of potential development has already occurred); bioenergy, biomass, and hydroelectric power are at the beginning of the maturity phase (59.7% progress to saturation); tidal and wave energy are in the middle of the maturity phase (71.5% progress to saturation); green hydrogen and clean energy are in the saturation phase (99.0%); renewable energy and sustainable development goals are in the saturation phase (99.0%), and energy policy and technological innovation in renewable energy are in the middle of the maturity phase 68.0%). These results reflect the overlap between different topics rather than the individual scope of each field of research.
The transition toward low-carbon and circular Municipal Solid Waste (MSW) systems requires integrated evaluation approaches that consider environmental performance, technological maturity, and governance capacity. This study presents a structured, systematic review of MSW disposal and treatment practices published between 2018 and 2026, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. A total of 71 studies were included and analyzed. Due to heterogeneity in methodologies, system boundaries, and reported indicators, no formal meta-analysis was conducted. Instead, the review provides a comparative and qualitative synthesis of key environmental indicators and structural determinants. Results indicate a transition from open dumping toward engineered landfills and advanced treatment technologies, including waste-to-energy and biological processes. Open dumping is consistently associated with high greenhouse gas emissions and environmental risks, while engineered systems improve containment and enable partial resource recovery. The findings highlight that environmental performance is not determined solely by technology but by the interaction between infrastructure design, operational quality, governance capacity, and economic conditions. The proposed analytical framework supports context-sensitive waste management strategies aligned with circular economy principles and climate mitigation objectives.
Polyunsaturated fatty acids, particularly gamma-linolenic acid, are recognized for their therapeutic and nutritional properties. Zygomycetes, such as Cunninghamella elegans, represent a promising microbial platform for sustainable gamma-linolenic acid (GLA) production as an alternative to conventional sources. Despite this potential, the immunomodulatory activity of metabolites from C. elegans has not been previously explored. In this study, C. elegans was cultivated on hydrolysates from discarded residues of Pleurotus spp. cultures (DRPC-HL), optimized to release assimilable compounds, promoting valorization of low-value biomass within a circular bioeconomy. Dry mycelial biomass, lipid-free biomass, and intracellular lipids from these cultures, alongside previously reported C. elegans cultures grown under nitrogen-excess (N-Xs) and nitrogen-limited (N-Lim) conditions, were tested on THP-1-derived macrophages, under lipopolysaccharide (LPS)-induced inflammatory conditions. Following in vitro gastrointestinal digestion, dry biomass and lipid-free dry biomass fractions upregulated the anti-inflammatory cytokine IL10 and downregulated IL1B and TNF, particularly from N-Xs and DRPC-HL cultures. Lipids mainly enhanced IL10 expression, especially when derived from N-Xs cultures. No changes were observed in upstream regulators (TLR2, TLR4, NFKB1, RELA), suggesting a feasible post-receptor immunomodulatory action. Overall, these findings highlight the dual value of fungal bioproducts derived from agro-industrial residues, combining sustainable bioprocessing with bioactive compound generation, supporting environmentally friendly microbial platforms for industrial applications.
