Environmental Progress & Sustainable Energy最新文献

This study evaluated the effects of torrefaction temperature on the grindability of Japanese cedar (Sugi) and fibrous biomass particles, while addressing the limitations of the conventional Rittinger's law. The standard Rittinger's law physically failed as the specific surface area difference ($��\Delta �S�$) became negative at certain temperatures. To resolve this, a modified Rittinger's law utilizing the skeletal density difference ($��\Delta �{\rho }_s�$), which represents the intrinsic volumetric destruction, was proposed. This novel index consistently maintained a positive value, demonstrating its validity where conventional metrics fail. Analysis revealed species-specific mechanical responses: cedar showed a peak in resistance at intermediate temperatures due to the interplay of brittleness and hardness, while fibrous biomass particles showed a continuous decrease in grindability. Scanning electron microscopic analysis further elucidated that these trends stem from distinct grinding mechanisms—surface stripping for cedar and volumetric grinding for fibrous biomass particles. These findings contribute to the global goal of carbon neutrality by optimizing biomass co-firing and milling processes.

This study aims to develop sustainable two-layer cement mortar tiles by incorporating industrial by-products—granite dust (GD) as a fine aggregate replacement and marble powder (MP) as a partial cement substitute—and to optimize their composition for enhanced performance and reduced environmental impact. A factorial design with 12 mix formulations was used to evaluate the individual and combined effects of GD and MP on physical, mechanical, and durability properties. The results show that GD incorporation leads to improved matrix compactness, as evidenced by reduced water absorption (up to 66% at 15% replacement) and porosity (over 50% reduction). MP contributes additional improvements in density and strength. Based on macroscopic property correlations and established literature, these improvements are attributed to enhanced particle packing and the filler effect of the waste materials. The optimal mix (15% GD + 10% MP) achieved the highest bulk density (13.61 kN/m³) and modulus of rupture (14.37 MPa). Multi-objective Pareto optimization and regression modeling (R² >0.90) confirmed the synergistic benefits of combining these materials. Furthermore, using MP reduced cement consumption by 10%, lowering the embodied CO₂ and improving the strength-to-carbon efficiency index. These findings demonstrate that GD and MP can be effectively used to produce high-performance, eco-friendly tiles suitable for residential and light commercial flooring, thereby supporting waste valorization and promoting sustainable construction practices.

This study presents a sustainable “waste-to-resource” approach by converting sugar beet pulp into a high-performance sulfonated biochar (CSBP) through a streamlined chemical carbonization route. By utilizing concentrated sulfuric acid, simultaneous carbonization and surface functionalization were achieved under mild conditions, eliminating the need for high-temperature pyrolysis. Comprehensive physicochemical characterization revealed a highly porous carbonaceous framework enriched with sulfonic acid groups, yielding a fine-grained adsorbent (<20 μm) with high thermal stability and a carbon content of approximately 85 wt%. Batch adsorption experiments were systematically performed to evaluate the effects of adsorbent dosage, solution pH, initial dye concentration, contact time, and temperature. The adsorption process exhibited high removal efficiency (>90%) at the natural pH of the dye solution, eliminating the need for pH adjustment. Kinetic analysis demonstrated that the adsorption behavior followed a pseudo-second-order model, indicating that chemisorption governs the rate-controlling step, with an activation energy of 9.01 kJ/mol. Equilibrium data were best described by the Langmuir isotherm, confirming monolayer adsorption on a homogeneous surface, with a maximum adsorption capacity of 2.70 mmol/g at 55°C. Thermodynamic parameters (ΔH° = +9.301 kJ/mol and negative ΔG° values) indicated that the adsorption process is endothermic and spontaneous. The adsorption mechanism was attributed to the synergistic contribution of electrostatic interactions, π–π stacking, surface complexation involving sulfonic and oxygen-containing functional groups, and pore-filling effects. Overall, this study demonstrates that sulfuric acid-carbonized sugar beet pulp is a highly effective and environmentally benign adsorbent for cationic dye removal.

Due to fossil fuel depletion and environmental concerns, alternative fuels such as biodiesel, bio alcohols, bio-oil, and plastic oil are being investigated for internal combustion engines (ICEs), providing a way to lower emissions and increase energy security. While these oxygenated biofuels reduce particulate matter, carbon monoxide, and unburned hydrocarbons, they may increase nitrogen oxide emissions, and pure biofuels may produce somewhat less power than traditional diesel. While many studies have already reported on any one type of these fuels, the comparison between them is lacking. This article includes an in-depth assessment of current research on the usage of biodiesel, bio-alcohol, bio-oil, and plastic oil as well as their characteristics, internal combustion engine (ICE) performance, and emissions. The review discusses the sort of engines powered by these fuels, their density, ignition quality (cetane/octane), viscosity and stability, engine performance, engine emissions, and finally their suitability and challenges. This comprehensive review also highlighted the future focus on the importance of fuel optimization through improved engine control, dual-fuel concepts, and additive integration, as well as the development of next-generation biofuels for sustainability.

The drugs appeared as emerging contaminants in aquatic environment needs proper treatment to safeguard the ecosystem. The present report deals with synthesis of reduced graphene oxide nanosheet (rGONS) from graphite powder by modification of Hummer's method and subsequent thermal treatment and has been tested for the potential removal of Galantamine (Alzheimer's drug). The immobilization of the drug on the adsorbent was confirmed from characterization of the material done by UV–Vis, FTIR, Raman spectroscopy, XRD, SEM, FESEM, TEM and EDS analysis before and after the adsorption of drug. Adsorption was dependent on the operational variables viz. adsorbent dose, initial concentration of drug, contact time, temperature and pH. The interactive influence of the variables was investigated following response surface methodology (RSM) with built up a mathematical model and mapped in design space by response surface and contour plots. The percentage contribution of the variables to the response is found to be temperature (D: 33.13%) > initial concentration (B: 32.88%) > adsorbent dose (A: 16.11%) > contact time (C: 1.38%) > pH (E: 0.22%) obtained from FFD study. The optimized adsorption condition is: adsorbent dose: 10 mg, initial concentration: 40 mg L⁻¹, temperature: 313 K obtained from CCD. The rGONS-drug adsorption process follows a pseudo second-order rate law, Langmuir isotherm and is thermodynamically feasible (−ΔG₀ = 11.35 kJ mol⁻¹). The higher specific surface area, abundant sorption sites, one pot synthesis, short equilibrium time (30 min), high adsorption capacity (81.96 mg g⁻¹), regeneration capacity, and reusability properties makes it a promising nano adsorbent for water remediation.

In this study, a bio-composite composed of TiO₂-incorporated bio-silica (BS), silk fibroin (SF), and polyurethane foam (PUF) was developed and evaluated as a photocatalytic material for the removal of Turquoise Blue (TB) dye. The prepared bio-composite was analyzed for its formation, surface morphology, and thermal properties using FTIR, XRD, TGA, and SEM, respectively. The amorphous nature of the composite was clearly revealed through XRD and SEM studies. Initially, the composite adsorbed a substantial amount of the dye on its surface in the dark, after which it underwent photocatalysis under light exposure. The photodegradation efficiency of the BS/SF/PUF/TiO₂ bio-composite for TB was assessed, and the results showed a significant enhancement in the photocatalytic degradation of TB compared to pure TiO₂. The degradation efficiency of BS/SF/PUF/TiO₂ reached approximately 99.96%. The high electron–hole charge separation capability was the driving force behind the consistent bandgap, which contributed to the exceptional photodegradation efficiency of the bio-composite. The bandgap of the BS/SF/PUF/TiO₂ bio-composite was determined to be 2.9 eV. The photodegradation efficiency was evaluated by varying parameters such as pH, irradiation time, catalyst dosage, and initial dye concentration. The experimental data were fitted to the Langmuir–Hinshelwood model to analyze the rate constant and explore the possible photocatalytic mechanism. This study demonstrates that the BS/SF/PUF/TiO₂ bio-composite holds significant potential as both an adsorbent and a photocatalyst for wastewater treatment, with the added advantage of being easily reusable.

The extensive utilization of synthetic dyes, such as Reactive Red S3B (RRS3B), and their discharge into water bodies has seriously threatened the environment and human health. Green zero-valent copper nanoparticles (Cu⁰ NPs) were synthesized via Ficus Benjamina leaves extract as a natural reducing and capping agent. FTIR and SEM were used to evaluate the generated Cu⁰ NPs, verifying their production, stability, and morphology. The ensuing nanoparticles of zero-valent copper ranged in size from 16.2 to 18.5 nm. Under various conditions, the adsorption and catalytic effectiveness of the Cu⁰ NPs in eliminating (decolorizing) RRS3B dye from aqueous solutions were precisely examined. After testing several adsorption models, the Langmuir isotherm (q_max = 126.58 mg g⁻¹, R² = 0.9995) showed the best fit, indicating monolayer adsorption. The kinetic analysis supported the pseudo-second-order model (R² = 0.9994), indicating chemisorption. Considering the information gathered and the successful research, the green Ficus-nZVCu adsorbent is a hopeful material for removing RRS3B owing to its high surface area and redox activity. Response surface methods and artificial neural network models confirmed the impact of major operational parameters. This study features the potential of green-synthesized Cu° NPs for the efficient and environmentally safe remediation of wastewater contaminated with dyes.

Cyclic variations in compression ignition engines are undesirable because they reduce efficiency, increase emissions, and limit power output. In this context, the adoption of alternative fuels has gained significant attention as a potential strategy to improve combustion characteristics. Biofuels, including biodiesel and alcohol-diesel blends derived from both edible and non-edible feedstocks, serve as viable alternatives to fossil fuels due to their inherent oxygen content and enhanced combustion characteristics. This review systematically analyzes peer-reviewed experimental studies from the past two decades to assess cyclic combustion variability in diesel engines powered by biofuel-diesel blends, focusing on in-cylinder pressure dynamics, indicated mean effective pressure (IMEP), pressure rise rate, and heat release characteristics, and comparing statistical and wavelet-spectrum-based diagnostic methodologies. Conventional statistical metrics, including the coefficient of variation (COV) and correlation-based measures, primarily assess the overall magnitude of fluctuations but offer limited insight into the temporal evolution and predominant modes of cyclic combustion variability, which can be more effectively analyzed using advanced time-frequency methods. Data indicate that optimal blends can decrease COV_IMEP by 20–35% with particular injection procedures; however, statistical convergence (about 150 cycles) fails to disclose underlying oscillatory patterns. Conversely, Continuous Wavelet Transform (CWT)-based methodologies, specifically Wavelet Power Spectrum (WPS) and Global Wavelet Spectrum (GWS), provide adaptive time-frequency decomposition, discerning intermittent short-period (3–10 cycles) and long-period (>150 cycles) instability bands. Wavelet analysis reveals substantial reductions in spectral power (e.g., an almost 80% decrease under optimal injection pressure settings), validating enhanced combustion stability beyond the insights provided by COV alone.

The use of power generated by constructed wetland–microbial fuel cells (CW-MFCs) has recently attracted considerable attention. This study is the first to investigate the use of electricity generated by CW-MFCs to power constructed wetland microbial electrolysis cells (CW-MECs) for enhanced pollutant removal from tailwater with a low C/N ratio. Substrate optimization strategies to improve the electricity-generation performance of CW-MFCs were systematically investigated, and the performance of the CW-MFC and CW-MEC coupled system for advanced tailwater treatment was evaluated. The results demonstrated that CW-MFCs with a pyrite (PY) anode substrate exhibited higher voltage and current density than those with activated carbon (AC) or mixed pyrite–activated carbon (PA) substrates. The PY system achieved a 4.4-fold higher power density (93.98 mW/m³) than the AC system (21.29 mW/m³). Substrate optimization also influenced the microbial community structure and abundance in the CW-MFC anode zone. Specifically, the PA and PY systems showed a significantly (p < 0.05) higher relative abundance of electroactive bacteria (EAB) than the AC group, while the AC and PA systems harbored a higher relative abundance of denitrification-associated bacteria. Substrate type is a key environmental determinant driving microbial community differentiation. The CW-MFC and CW-MEC coupled system achieved removal efficiencies of 89.20 ± 1.80% for COD, 61.03 ± 0.60% for NH₄⁺-N, 94.82 ± 1.87% for NO₃⁻-N, and 83.60 ± 3.35% for total phosphorus (TP) from low C/N ratio tailwater. The self-powered CW-MFC and CW-MEC coupled system presents a transformative pathway toward energy-neutral advanced wastewater treatment, effectively addressing key challenges in sustainable water management.

The utilization of agrarian waste such as rice straw in construction materials is limited by its high moisture sensitivity and susceptibility to biodegradation. At the same time, building energy consumption accounts for approximately 40% of global greenhouse gas (GHG) emissions worldwide, highlighting the urgent need for construction materials with minimal or near-zero carbon footprints. This present work investigates rice straw waste composites that can serve as a sustainable alternative in building sandwich constructions. The effect of three different coatings, viz., adhesive binder, epoxy resin, and polyethylene terephthalate (PET), on the biodegradability of rice straw composites is evaluated. The effect of water and alkali pre-treatment on rice straw is also evaluated through biochemical testing, water absorption, soil burial experiments, and microstructural characterization. The investigations suggest that the coatings can improve the structural integrity of rice straw and hence their durability. In comparison to the uncoated stubble waste composites, the weight loss of epoxy and PET-coated stubble waste composites reduced by ~65%–70%. Both coated and uncoated rice straw composites showed much lower thermal conductivity in comparison to the conventional building materials, highlighting their suitability for the development of building thermal envelopes.