Electrification of residential heating via heat pumps is a key aspect of the global strategy to reach Net Zero. This is because heat pumps which can convert electricity directly to heat will almost directly reflect the carbon intensity of the electricity they use. The reduction in greenhouse gas emissions is dependent on the raw materials used, the source and quantity of electricity consumed for operation and end of life management of heat pumps. Therefore, it is necessary to evaluate the climate change impact and other sustainability aspects of heat pumps on a life cycle basis. 

However, heat pumps may be installed for individual buildings or as part of a heat network that supplies multiple properties, with significant differences between them in impacts from material usage, installation and operation. This review aims to synthesise and analyse the latest research to compare the environmental impacts of domestic heat pumps at these different scales, for new-build and retrofit cases. Following PRISMA protocols, a systematic search of peer-reviewed literature from 2017–2025 was conducted using the Web of Science and Scopus databases. The keywords used are as follows: 'Heat pump', 'Life Cycle Assessment', 'Environmental impact assessment', 'District heating', 'Domestic heating'. The number of studies found on the Web of Science database was 1256, with 1605 found on Scopus. 1006 studies were removed as duplicates, and the amount studies after removing duplicates were 1857. The review focused on studies quantifying impacts beyond operational energy use, specifically targeting embodied carbon, ozone depletion potential (ODP), resource depletion and the coefficient of performance (COP). 

We found that the life cycle impacts are interlinked with many factors, such as the characteristics of the electricity grid, the temperature lift, and the type of heat pump. We also note that there are differences in the methodological approaches, including choice of functional units and system boundaries, which limit the ability to cross-compare studies by non-experts. Despite this, the conclusions drawn suggest that geothermal heat pumps perform better than air source heat pumps. Moreover, future life cycle assessment studies on heat pumps will benefit by integrating temporal and spatial variations, such as heat pump performance with respect to the ambient temperature, and electricity grid greenhouse gas emission factors. This can help prioritise the deployment at scale of heat pumps on a wider scale based on the sustainability benefits when compared to conventional heating systems. 

The synthesis reveals that while domestic heat pumps generally exhibit lower upfront embodied carbon, they are frequently associated with higher cumulative refrigerant leakage and lower real-world efficiencies due to suboptimal installation. Conversely, district heat pumps consistently show lower environmental impact per kWh of heat delivered in high-density urban zones (>50 dwellings/hectare), primarily driven by the integration of waste heat sources and professionalized maintenance which prevents performance drift.

How to cite: Fadden, L., Radcliffe, J., and Mehta, N.: Decarbonising Residential Heating: A Systematic Review of Life Cycle Impacts for Residential and District Heat Pump Systems, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1219, https://doi.org/10.5194/egusphere-egu26-1219, 2026.

Water distribution networks (WDNs) are a critical component of modern society, responsible for delivering water to local communities and industries while maintaining continuous, stable flow within the system, which carries low-grade hydropower potential. These systems are vulnerable to disruptive events, such as pipeline failures and water contamination. To mitigate the risk of disruption events, recent EU policies have focused on the digitalisation of critical infrastructure, including WDNs and wastewater treatment plants (WWTPs), through the integration of Internet of Things (IoT) technologies. Digitalisation enables system operators to collect real-time data and perform predictive maintenance, thereby improving resilience and operational efficiency. Thus, system electricity requirements will increase to support IoT and digitalisation retrofitting.

This creates an opportunity to deploy energy-harvesting (EH) devices within WDNs and WWTP infrastructure that harness and utilise the resonant and kinetic energy inherent in water flow. Although the benefits of EH devices are often considered minimal and their energy outputs are low, EH devices are considered a viable power source for low-power sensors, such as pressure, contamination, and temperature sensors.

This study proposes and applies a feasibility assessment framework to evaluate EH devices as an alternative, decentralised power source for IoT-enabled monitoring in WDNs. The framework includes technical performance analysis, economic viability, and environmental impact assessments, combined with probability-based resilience modelling. It uses case-specific hydraulic, operational, design, and economic data to quantify EH power outputs, assess the costs of design and deployment, evaluate the environmental footprint of the devices, determine sensor energy requirements, and assess system resilience across different deployment scenarios.

Results demonstrate that the EH device has a mechanical power-generation capacity potential ranging from 0.049 to 36 watts, depending on the study location, flow conditions, and design characteristics. This EH generation capacity is sufficient to power pressure, contamination, and temperature sensors. The resilience modelling indicates that the detection probability of WDNs exhibits the most significant gains from adding sensors at low deployment levels. Thus, most of the improvement in detection levels occurs between deploying the first five to ten sensors; beyond this threshold, adding more sensors exhibits diminishing marginal returns to detection probability and system resilience. In addition, adding more sensors can significantly reduce system resilience by increasing power requirements, thereby placing excessive load on the power supply of the EH devices. Thus, it increases the risk of failure rather than enhancing resilience.

Overall, the results underscore the importance of strategic sensor allocation over high-density deployment and of balancing monitoring coverage with energy availability. Furthermore, the results show that EH devices are suitable power-generation technologies for supporting the digitalisation of WDNs and informing the design of new monitoring systems and sensor placement to enhance system reliability, enable cost-effective monitoring, and maximise mitigation benefits. In addition, the proposed framework provides decision-makers with a structured approach to assessing EH integration applications for digitalised WDNs, focusing on enhancing resilience through monitoring, conducting technical performance and cost-benefit analyses, assessing environmental trade-offs, and designing monitoring strategies aligned with sustainability and resilience objectives.

How to cite: Guðlaugsson, B., Stepanovic, I., Marguerite Bronkema, B., and Christian Finger, D.: Enhancing water system resilience and reliability: Application of Multidimensional Feasibility Assessment framework to assess if the deployment of energy harvesting devices in urban water systems enables a higher degree of system resilience., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19267, https://doi.org/10.5194/egusphere-egu26-19267, 2026.

Public trust is widely recognized as a key condition for public cooperation in the energy transition, yet surprisingly little is known about whether and how government communication can actively shape that trust. In particular, value-based framing strategies are often assumed to be a low-risk way to strengthen credibility, but empirical evidence on their effects remains scarce. This study examines how the value content and institutional source of government communication influence trust in practice, using a large-scale national experiment (N ≈ 3,000) embedded in an online Participatory Value Evaluation (PVE) on sustainable heat policy in the Netherlands.

Participants were randomly assigned to one of six experimental conditions or a value-neutral control group. The treatments varied along two dimensions: value-based framing (environmental, financial, or stability-related) and governance level (local versus national government). Trust in government was measured immediately before and after exposure, enabling a Difference-in-Differences design that isolates trust changes attributable to the communication treatments. To examine heterogeneity, the analysis combines DiD estimation with Latent Profile Analysis of baseline trust orientations and Honest Causal Forests to detect non-linear treatment-effect variation.

Across all specifications, value-based framing does not increase institutional trust and, in several cases, reduces it. The most consistent negative effect appears for stability framing delivered by local government. Importantly, these average null effects mask strong heterogeneity: trust responses differ substantially across latent trust profiles but not across socio-demographic groups. Individuals with higher baseline trust tend to react more negatively to value-laden messages, whereas lower-trust respondents show weakly positive or neutral responses. This indicates that communication sensitivity is driven primarily by pre-existing trust dispositions rather than demographic characteristics.

By contrast, participation in the PVE itself generates a modest but robust increase in trust across both treated and control groups, independent of framing. This pattern suggests that being invited to engage with policy trade-offs and provide input may strengthen perceptions of procedural fairness and benevolence more effectively than persuasive messaging. Overall, the findings challenge common assumptions in the nudging and public communication literatures. The findings suggest that participatory decision tools may strengthen trust, whereas value-laden communication risks unintended negative effects.

How to cite: Goes, K., Thépaut, L., Mouter, N., Chappin, E., and Kluiving, S.: Participation Builds Trust, Not Framing: Insights from a National Energy-Transition Experiment , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13892, https://doi.org/10.5194/egusphere-egu26-13892, 2026.

This work utilizes the universal concepts of energy and Carnot Heat Engine to explain the formation of natural capital types as products of evolutionary processes, activated and driven by planetary heat engines. On this foundation, it further argues on the need for a fundamental redesign of the global economic and financial architecture with consistency to thermodynamic principles. The Laws of Thermodynamics dictate that the generation of physical work in a system with well-defined boundaries requires the existence of a heat gradient. Beginning from a typology of planetary natural capital species -ranging from fossil and nuclear fuels to minerals, biomass and genetic information- it is argued that the global stock of natural capital essentially constitutes and accumulated surplus of useful work or exergy, as the fundamental potential of economic growth. The exergy embodied in each natural capital type establishes three major economic functions: (1) for inorganic natural capital (such as fossil fuels, nuclear materials and minerals) it sets a reference state above thermodynamic equilibrium that contains intrinsic economic value and (2) for organic natural capital (such as chemically structured biomass, ecosystem functions and genetic information) it sets an optimal ecological state, sustained by daily planetary exergy flows. These two functions derive the third, (3) on the global economy’s ecological constraints to generate heat and material wastes -from the thermodynamic transformation of natural capital into economic goods- that distort the optimal ecological state. On these grounds, this work develops a quantitative economic framework with consistency to the laws of thermodynamics, introducing innovative key metrics on humanity’s evolutionary course by its energy paradigm, the thermodynamic conditions for a steady-state economy, the Jevons’ Effect as an inevitable evolutionary pressure towards energy paradigm shifts, the re-postulation of the Hartwick’s Rule of intergenerational equity on thermodynamic foundations, as well as the Scarcity Rent as a financial investment instrument for energy technology transitions.

Keywords: energy, Carnot Heat Engine, natural capital, Laws of Thermodynamics, useful work, exergy, economic growth, energy paradigm, Jevons’ Effect, Hartwick’s Rule, intergenerational equity, Scarcity Rent

References

• Kümmel Reiner. The Second Law of Economics. New York: Springer-Verlag; 2011
• Ayres Robert U, Warr Benjamin. The Economic Growth Engine. Cheltenham: Edward Elgar Publishing Ltd; 2009.
• Roegen Nicolas Georgescu. The Entropy Law and the Economic Process. Cambridge MA: Harvard University Press; 1971.

How to cite: Karakatsanis, G.: Energy, natural capital and economic growth, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13588, https://doi.org/10.5194/egusphere-egu26-13588, 2026.

Solar-driven interfacial evaporation (SDIE) offers a sustainable route for treating high-salinity wastewater; however, reconciling ultra-high evaporation rates with long-term salt resistance remains a critical bottleneck. Herein, a structurally robust, sponge-templated composite aerogel (PCPG) is developed by confining a polyvinyl alcohol (PVA)-based semi-interpenetrating network (semi-IPN) within a polyurethane (PU) sponge skeleton. In this architecture, Carbon Black (CB) and PEDOT:PSS are synergistically integrated to ensure broadband solar absorption (>90%) and reinforce the gel matrix.  The abundant hydrophilic groups within the polymer chains regulate the water state, effectively reducing the evaporation enthalpy to 831.5 J g⁻¹. Crucially, the composite features a hierarchical porous structure: the gel's micropores facilitate rapid capillary water supply, while the sponge's macropores enable efficient back-diffusion of salt ions. Leveraging these synergistic effects, PCPG achieves an exceptional pure water evaporation rate of 6.13 kg m⁻² h⁻¹ with 123.08% efficiency under 1 sun irradiation. Remarkably, it sustains a stable rate of 5.21 kg m⁻² h⁻¹ in 20 wt% NaCl brine without salt accumulation.Validated by both experiments and numerical simulations, this work presents a scalable, salt-resistant solution for zero-liquid discharge (ZLD) desalination and industrial brine management.

How to cite: Li, F.: Composite Aerogel with Hierarchical Hydrophilic Networks for Solar Evaporation and Salt-Resistant Brine Concentration, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1909, https://doi.org/10.5194/egusphere-egu26-1909, 2026.

Inspired by sand roses and the geological process of pressure-solution creep, this study presents a geomimetic, low-energy approach for producing sustainable bricks from vernacular geomaterials. By adapting the cold sintering technique, sand - uncalcined gypsum mixtures are densified at room temperature using minimal water and moderate pressure, thereby circumventing the high energy demands, chemical use, and substantial carbon emissions associated with conventional fired-clay or cement-based brick production. The research was conducted in two sequential experimental phases to bridge the gap between fundamental mechanism and practical manufacturability.

The first phase, conducted on small laboratory-scale samples, established the fundamental controls on mechanical performance. It demonstrated that gypsum acts as an effective binder at room temperature via a dissolution–precipitation mechanism. Critical processing parameters were identified, including gypsum content, gypsum particle size, pressure magnitude and loading mode. Notably, cyclic loading significantly enhanced the unconfined compressive strength (UCS) without requiring increases in gypsum content or applied pressure, enabling mixtures to achieve strengths comparable to or exceeding those of equidimensional concrete bricks.

The second phase focused on upscaling the process to brick-relevant dimensions. By optimizing critical parameters such as pressure duration, drying time, and ambient humidity, the study successfully produced 50 mm cubes that meet ASTM standards for load-bearing masonry (13.8 MPa). The optimized process—applying only 50 MPa of uniaxial pressure for 5 minutes, followed by one day of drying (50 °C) at controlled humidity (40 %)—yielded sand–gypsum compacts with a UCS of approximately 18 MPa. This result confirms that reduced processing times are feasible for manufacturing, provided the drying environment is carefully regulated.

Overall, this geomimetic fabrication strategy leverages locally abundant resources, drastically reduces embodied energy and water consumption, and supports circular economy principles through material recyclability. It offers a viable, sustainable alternative for construction in hot, arid climates, directly contributing to global sustainability goals.

How to cite: Radwan, O., Hussein, M., Assaggaf, R., Humphrey, J., Al-Hashem, M., Mahmoud, A., and Abdelaal, A.: A Geologically Inspired Low-Energy Construction Material Based on Vernacular Geomaterials for Hot and Dry Environments, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2354, https://doi.org/10.5194/egusphere-egu26-2354, 2026.

  Global industrialization and population growth have increased the demand for energy and food, leading to a rise in food-processing by-products. Okara (soybean residue) is one of the most abundant by-products, with an annual production exceeding 14 million tons worldwide. Despite its high organic content, okara is often discarded due to its high moisture content and limited processing options. Converting okara into energy or high-value materials has become a significant challenge in light of resource scarcity and circular economy principles. This study proposes an efficient conversion pathway that combines hydrothermal treatment (HT-carbonization/liquefaction) with anaerobic digestion (AD) to transform okara into usable resources without energy-intensive drying.

  The hydrothermal process converts okara into bio-crude oil, hydrochar, and nutrient-rich aqueous phase, while simultaneously breaking down its high cellulose and protein content under high temperature and pressure. This process facilitates the conversion of large molecules into smaller molecules, which enhances methane production during subsequent anaerobic digestion and improves energy recovery efficiency.

  Experiments were conducted in a 500 cm³ high-temperature, high-pressure stainless-steel reactor equipped with a mechanical stirrer. Okara and deionized water were added at solid-to-liquid ratios of 1:10 and 1:5. After nitrogen purging, the reactor was pressurized to 2 MPa. The reaction temperature ranged from 200 to 300°C, with reaction times between 60 and 360 minutes. Results showed that the highest yields of hydrochar (38%) and bio-crude oil (31%) were achieved at 200°C and 120 minutes. Yields decreased when temperatures exceeded 230–250°C or reaction times were prolonged, as more carbon shifted to the aqueous and gaseous phases. At 300°C with short reaction times, moderate yields of hydrochar (20–23%) and bio-crude oil (25–26%) were obtained, indicating that high temperatures with limited exposure promote oil formation without excessive degradation.

  The remaining nutrient-rich liquid phase was subjected to co-digestion with sludge, maintaining a 1:1 liquid-to-sludge ratio based on volatile solids content. Gas was collected daily, and the bottles were opened weekly for gas, solid, and liquid analysis, as well as biodegradability assessments. Anaerobic co-digestion further enhanced methane production, significantly improving energy recovery. The liquid phase provided biodegradable organic matter, which was broken down by anaerobic microorganisms, resulting in increased methane yield and improved overall energy recovery efficiency.

  Additionally, a life cycle assessment (LCA) was conducted to evaluate the environmental impacts of the hydrothermal treatment combined with anaerobic digestion. From number of LCA paper results, it was shown that this integrated process had a lower environmental impact and higher resource efficiency compared to traditional waste management methods, such as landfilling, incineration, or direct AD.

  In conclusion, this integrated system presents a viable waste-to-resource pathway. The hydrochar produced can be used as a soil conditioner, and the bio-crude oil as a fuel. Methane can be utilized for power generation, while the remaining digestate can be applied as liquid fertilizer. The combination of hydrothermal treatment with anaerobic digestion, alongside the incorporation of life cycle assessment, highlights a promising circular economy strategy that reduces carbon emissions, fosters energy production, enhances resource recovery, and supports the sustainable use of agricultural by-products.

How to cite: Lin, C. J., Huang, Y.-Z., and Fan, C.: Valorization of Okara using Hydrothermal Treatment in combination with Anaerobic Digestion for Resource Recovery, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2926, https://doi.org/10.5194/egusphere-egu26-2926, 2026.

The efficient development of shale gas in mountainous regions is critical for supporting China's energy security and transition towards carbon neutrality. However, the economic viability of such projects is heavily constrained by complex surface conditions, which introduce significant cost uncertainties that are difficult to quantify using conventional assessment methods. To address this, we develop a quantitative techno-economic model for mountain shale gas that integrates multi-source geospatial data. Framed within a real options analysis, the model expands the standard net present value calculation by incorporating not only traditional costs (e.g., fixed operations, exploration, royalties, surface engineering) but also spatially-variable costs derived from geospatial analysis. These include hazard mitigation, water access, ecological restoration, and community compensation.

Key spatial parameters are derived from open-access data, including high-resolution DEMs, multispectral imagery, land cover maps, infrastructure networks, and geohazard products. These datasets inform a comprehensive surface suitability assessment based on terrain ruggedness, slope, vegetation indices, and proximity to infrastructure, enabling the identification of viable wellpad locations and the estimation of maximum drillable wells. This process quantitatively translates spatial constraints into economic inputs. Monte Carlo simulation is then employed to analyze the sensitivity of project economics to key variables, particularly the number of wells and natural gas price volatility.

An application in the mountainous region of Western Hubei demonstrates the model's effectiveness in differentiating the economic potential of various blocks. The results quantify the substantial negative impact of surface complexity on both net present value and real option value, confirming well count and commodity price as the primary drivers of financial risk. This study presents a novel decision-support tool that systematically embeds geospatial data into the economic evaluation of shale gas resources in complex terrain. The developed "geospatial-data-to-economic-parameter" framework provides a transferable methodology for the techno-economic assessment of natural resource projects subject to strong spatial constraints.

How to cite: Yuan, K., Xu, X., Liu, K., and Qiu, J.: A Quantitative Techno-Economic Assessment Model for Mountain Shale Gas Development Driven by Multi-Source Geospatial Data, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8749, https://doi.org/10.5194/egusphere-egu26-8749, 2026.

Driven by the goals of sustainable development, resource development demands drilling technologies with high efficiency and low energy consumption. Scientific drilling, as a key tool for accessing subsurface resources and geoscientific information, relies on energy-efficient drilling systems to achieve sustainable resource exploitation. In response, this study presents a self-balancing drilling rig hoisting system that surpasses conventional rigs in both drilling efficiency and operational stability while significantly reducing energy consumption. To characterize the dynamic performance of this rig’s hoisting system, a mathematical model was developed through theoretical analysis and validated via numerical simulation. The results demonstrate that using the proposed system for tripping operations can increase efficiency by more than 40%, and the rig operates more stably than traditional systems. Moreover, the self-balancing rig hoisting system employs two coordinated traveling-block systems to achieve self-balance against the reaction torque generated by the winch, while effectively recovering and utilizing the gravitational potential energy released during drill stem lowering. These findings provide a novel approach to improving drilling efficiency and reducing energy consumption, with significant engineering implications and theoretical value for the development of high-efficiency, energy-saving drilling operations.

How to cite: Song, W.: Dynamic Modeling and Performance Analysis of a Self-Balancing Drill Hoisting System for Efficient Resource Development, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12110, https://doi.org/10.5194/egusphere-egu26-12110, 2026.

In the context of sustainable development, high-efficiency drilling operations have become a key objective in advancing scientific drilling technology. Given the frequent coring and tripping operations involved in ultra-deep scientific drilling, automating and streamlining the make-up/breakout and handling/transfer of drill pipe wellhead tools is a critical technological pathway for improving overall drilling efficiency. To meet the demand for faster tripping operations, this study designed a high-efficiency transfer system for ultra-long drill pipe and determined its optimal operating strategy by combining experiments with finite element analysis. All experiments were conducted on a dedicated intelligent drilling platform. For three drill pipe sizes (3.5 in, 4.5 in, and 5 in), a series of tests were performed, including four-stand lifting tests, asynchronous up/down transfer tests, and inclined lean-against tests. The results indicate that the maximum bending deformation occurs within 16–21 m above the wellhead, with a peak deflection of 549 mm. Based on these findings, four-stand drill pipe are best transferred using an integrated “lower support + upper clamp” mode, whereas drill collars are better handled using a push-and-support mode. Subsequently, aiming to achieve 25 stands per hour during tripping operations, a corresponding tripping workflow and an offline operational scheme were developed. Finally, an integrated control strategy for the transfer system was proposed, considering the overall rig layout and tubular-handling process requirements. Through systematic design, experimental validation, and process optimization, this study has developed an efficient handling method and integrated control scheme for ultra-long drill pipe during drilling and tripping operations in ultra-deep scientific drilling. The findings provide technical and equipment support for the sustainable development and efficient utilization of resources.

How to cite: Gao, K.: Design and Experimental Study of an Ultra-Long Drill Pipe Transfer System for Efficient Continuous Operations in Resource Development, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12238, https://doi.org/10.5194/egusphere-egu26-12238, 2026.

Pyrophyllite is a mineral known for its chemical inertness, thermal stability and low thermal conductivity. Such properties are making it a suitable material for modern and advanced insulation technologies. The study evaluates the potential of pyrophyllite-rich natural resources for industrial usage in heat-resistant, eco-friendly and sustainable geocomposite insulation panels when combined with plant-based fabrics such as cotton, jute and linen.

The samples obtained from the Pütürge district of Malatya, where the majority of pyrophyllite deposits in Türkiye are located, were characterized mineralogically and geochemically in order to evaluate their suitability for industrial purposes and geocomposite production. Pyrophyllite-rich sample powders were micronized to improve bonding between mineral particles and fabric fibers, while plant-based fabrics were mercerized with sodium hydroxide for better surface reactivity. Mercerized fabrics were impregnated with a binder solution which includes the micronized powder and sodium silicate and later subjected to heat treatment to provide stability. Thermogravimetric (TGA) and Differential Scanning Calorimetry (DSC) analyses on both untreated and impregnated fabrics revealed their mass-loss characteristics, thermal decomposition behavior and their flame-retardant potential.

The results indicate that impregnating the plant-based fabrics with pyrophyllite significantly increases the thermal performance. Among these fabrics, the best improvement in thermal mass retention is observed in cotton, followed by jute and linen. Jute fabrics exhibit the highest degree of thermal endurance, maintaining structural stability up to approximately 600 °C. The positive change in heat resistance for cotton and linen is relatively weaker, but all mineral-impregnated fabrics develop a char layer after combustion, with residual masses of 33-43% for jute, 17-20% for cotton, and 15-18% for linen. This mineral-based barrier is essential for sustainable thermal insulation, as it reduces heat transfer and supports the long-term integrity of the resulting geocomposites. In conclusion, the results demonstrate that pyrophyllite-impregnated plant-based fabrics, especially jute, are highly suitable for production of environmentally friendly, sustainable, thermally resistant and flame-retardant geocomposites for insulation purposes.

How to cite: Aykasım, D., Toksoy Köksal, F., and Kılıç, A.: Thermal performance improvement of plant-based fabrics via pyrophyllite impregnation: an environmentally friendly approach to geocomposite insulation materials, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-383, https://doi.org/10.5194/egusphere-egu26-383, 2026.

In Taiwan, over 400,000 tonnes of fish are consumed annually through commercial fish markets, with approximately 45% converted into low-value fish waste (FW), including viscera, bones, and scales, resulting in more than 200,000 tonnes of fish waste each year. These fish wastes are characterized by high moisture content and high biodegradability, particularly proteins and lipids. They are predominantly managed through low-efficiency practices such as landfilling, composting, or feed conversion, which often attract environmental concerns.

Anaerobic digestion (AD) is a conventional technology for converting organic waste into renewable energy. Previous studies have shown that AD of fish waste is frequently inhibited by long-chain fatty acids and high nitrogen content, leading to limited energy recovery and the generation of large volumes of digestate that require further treatment. Meanwhile, hydrothermal liquefaction (HTL) can effectively convert high-moisture and heterogeneous biomass materials into bio-crude oil without the need for energy-intensive drying, making it particularly suitable for anaerobic digestates.

This study investigates the integration of anaerobic digestion as a pre-treatment step with HTL to explore the resource recovery potential of liquid and solid digestate derived from fish waste. Fish waste was subjected to anaerobic digestion under five different substrate-to-inoculum (S/I) ratios, and HTL subsequently treated the resulting digestate under subcritical water conditions at temperatures ranging from 275 to 325 °C with a residence time of 30-60 min. The distribution and characteristics of the main HTL products, including bio-crude oil, solid residue, and aqueous phase, were analyzed.

The anaerobic digestion results showed variable biomethane production across different S/I ratios (1.84 ± 0.27-93.45 ± 8.84 mL CH₄ g^-1 VS). Notably, the AD process was utilized to partially degrade macromolecules while preserving sufficient organic carbon for subsequent HTL. Under HTL conditions at 325 °C for 60 min, bio-crude oil yields reached over 50 wt%. Gas chromatography–mass spectrometry (GC–MS) analysis indicated that the bio-crude oil was dominated by lipid-derived aliphatic amides, alongside protein-derived nitrogen-containing heterocyclic compounds, including lactams and fatty acid pyrrolidides. This suggests that the organic constituents of fish waste were effectively transformed into the oil phase with promising potential for further upgrading and valorization, while partially incorporating nitrogen into stable oil-phase compounds.

Furthermore, a life cycle assessment (LCA) framework was applied to compare this integrated AD–HTL pathway with traditional fish waste management practices to evaluate its potential environmental benefits in terms of resource recovery and pollution mitigation. Environmental benefits (such as carbon negativity and resource circularity) can be expected compared with conventional treatments for fish waste. Overall, the findings demonstrated that integrating biological and thermochemical processes could contribute to more sustainable approaches for managing biomass wastes, enabling the recovery of high-value secondary energy carriers and material resources.

How to cite: Hsu, T. Y., Huang, Y.-Z., and Fan, C.: Integration of Anaerobic Digestion and Hydrothermal Liquefaction for Resource Recovery from Fish Waste Digestate, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2934, https://doi.org/10.5194/egusphere-egu26-2934, 2026.

Tetracyclines (TCLs) are prevalent in environmental matrices and can bypass conventional wastewater treatment systems, thereby posing risks to human health and aquatic organisms. A 2D/3D Z-scheme Bi₁₂O₁₅Cl₆/Fe₂O₃@C (BFC) (specifically BFC-II, consisting 10% Fe₂O₃@C) heterojunction photocatalyst was utilized for the degradation of TCL, under visible light. At reaction conditions (initial TCL concentration: 5 mg/L; photocatalyst dosage: 0.5 g/L; solution pH: 7; temperature: 27 ± 2 ^oC), the photocatalyst demonstrated a degradation efficiency of approximately 95% after a reaction time of 90 min, with the pseudo-first order degradation rate constant (k) of 0.0329 min^-1. This could be associated with the reduced recombination rate of photoinduced charge carriers and their improved separation efficiency. Furthermore, hydroxyl radicals were identified as the primary reactive species facilitating the photocatalytic degradation of TCL. Overall, the BFC-II offers novel aspects related to the development of bismuth oxyhalide-based photocatalysts and their modification using Fe-MOF-derived materials.

How to cite: Singh, A. and Gupta, A. K.: Fe-MOF derived Fe2O3@C modified Bi12O15Cl6 for the visible light driven photocatalytic degradation of tetracycline, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16022, https://doi.org/10.5194/egusphere-egu26-16022, 2026.

Slurry-based photocatalyst reactors often suffer from secondary pollution due to catalyst leaching and low reusability, resulting from inefficient catalyst recovery. In this context, a visible light-driven Hematite/Bi₄O₅I₂ (HBI) nanocomposite was decorated on porous polyurethane foam (PU). The HBI nanocomposite was prepared by facile room temperature chemical precipitation, subsequently immobilized on PU via an eloquent chemical deposition technique. The inherent floating property of PU supported the mass transfer within the reactor, which could be attributed to the heat-induced convection across the HBI@PU  bed depth and stirring-induced convection throughout the phenolic solution. Thus, facilitating the transportation of pollutants and reactive species to the catalyst surface. As a result, the adsorption and photocatalysis were enhanced simultaneously. Moreover, the as-synthesized HBI and HBI@PU materials were characterized thoroughly using various techniques, including XRD, SEM, TEM, UV-DRS, and XPS. Furthermore, the photocatalysis of phenolics using HBI@PU was evaluated under optimal conditions: initial concentration of phenolics, 10 ppm; weight of catalyst material used, 0.25 g; pH, 6.2; and photocatalysis time, 80 min. The open-pore structure of the PU foam significantly enhanced the adsorption of phenolics, indicating that the foam provides additional porosity and adsorption sites. Consequently, the overall recorded removal of BPA, m-cresol, and phenol was 92.07 ± 1.53%, 84.25 ± 2.59%, and 59.41 ± 2.14%, respectively. Notably, only a marginal drop in removal efficiency was observed after subsequent recycles of photocatalysis. Hence, the as-synthesised visible light-driven floating HBI@PU photocatalyst holds potential applications in green and sustainable environmental remediation.

How to cite: Rawat, A., Srivastava, S. K., Tiwary, C. S., and Gupta, A. K.: Vis-LED responsive floating Hematite/Bi4O5I2 decorated polyurethane foam for synergistic adsorption-photocatalysis of phenols, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16043, https://doi.org/10.5194/egusphere-egu26-16043, 2026.

The widespread presence of antibiotics such as sulfamethoxazole (SMX) and tetracycline (TC) in aquatic environments poses a significant threat to ecological safety. In this study, aluminum-based multicomponent alloys engineered into two-dimensional quasicrystals (2D QCs) are presented as a robust and reusable photocatalyst for visible-light-driven degradation of SMX and TC. The catalyst achieved degradation efficiencies of approximately 94% for SMX and 89% for TC within 2 hours. The photocatalytic activity was thoroughly examined under various conditions, including pH variations, catalyst dosage, pollutant concentration, and the influence of common inorganic ions. The 2D QCs demonstrated excellent reusability with negligible metal leaching across successive cycles. Notably, substantial degradation was also achieved in real water matrices such as tap water, pond water, and municipal wastewater, highlighting their environmental practicality. Furthermore, in situ liquid-phase transmission electron microscopy captured the real-time degradation of SMX antibiotic molecules on QC surfaces. Phytotoxicity assays with Vigna radiata confirmed that the treated effluents were non-toxic, as seed germination and root growth were comparable to those of the controls. This work identifies 2D QCs as a highly effective photocatalyst for antibiotic removal in complex water systems, addressing an urgent global challenge.

How to cite: Manzoor, Z., Chowdhury, S., and Tiwary, C. S.: Mechanistic insights into antibiotic degradation using multicomponent 2D quasicrystals as robust photocatalysts via in situ TEM, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18267, https://doi.org/10.5194/egusphere-egu26-18267, 2026.