Environmental Progress & Sustainable Energy最新文献

Removing oil from oily emulsion wastewater is critically required prior to their downstream processing. However, the commonly used superhydrophilic separation membranes suffer from a complex hydrophilic modification process, high cost, and low efficiency. Herein, a cost-effective superhydrophilic aerogel membrane was presented via phase transfer and low-temperature plasma strategy using waste polyethylene as a building block. This plasma strategy involves directly and swiftly introducing oxygen functional groups with high surface energy onto the membrane surface, avoiding classical and sophisticated wet chemistry such as graft polymerization or physical modification. Such a direct plasma strategy renders the intrinsically hydrophobic polyethylene-based aerogel membrane stable and robust superhydrophilicity in harsh environments and excellent underwater anti-oil adhesion properties, thus achieving excellent gravity-driven oil-in-water emulsions separation with high flux (1940 L m⁻² h⁻¹) and high separation efficiency (98.9%). Additionally, this directly hydrophilized aerogel membrane presents favorable reusability, thereby maintaining satisfactory separation flux and efficiency even after 10 cycles of separation. Overall, this work provides a general and efficient avenue to surface engineer polyethylene-based aerogel membrane for rapid separation of oil-in-water emulsion wastewater.

Ni-citrate, Mg-citrate, and bimetallic NiMg-citrate complexes with equal molarities of Ni and Mg were synthesized using a green synthesis method to develop alternative electrolyte materials for capacitors. The synthesis was microwave-assisted using NiSO₄, MgSO₄, citric acid, acetic acid, distilled water, and ethanol as starting materials. Each complex electrolyte material was prepared as a 1% distilled water solution and used as electrolytes in the capacitor cell formed by the two-electrode method. Electrochemical performance evaluations were conducted using Cyclic Voltammetry (CV) and Electro Impedance Spectroscopy (EIS) analyses. Results showed significant differences in the materials' capacitive and electrochemical behavior. The redox reaction occurring in two regions (0.17 V and 0.45 V) with the Mg-citrate structure was observed only at 0.47 V levels with Ni dominance in the NiMg-citrate complex electrolyte. Cycle life analysis showed that the NiMg-citrate electrolyte is the second ideal structure after Mg-citrate at low scan rates, while at 50 mV s⁻¹ and above, this performance is below the Ni-citrate electrolyte. The highest discharge capacitance value of 378 mF cm⁻² was obtained in the Mg-citrate electrolyte. The findings show that Ni and Mg containing citrate complexes produced by green synthesis can be evaluated as eco-friendly, low-cost electrolyte alternatives.

Atmospheric Water Generation (AWG) systems have emerged as sustainable solutions to address water scarcity by condensing atmospheric moisture. However, the cold, dehumidified exhaust air generated during the condensation process in AWG systems is often released into the ambient environment without any secondary utilization. This study presents a novel dual-utility AWG system that harnesses the cold exhaust air for simultaneous water generation and cooling of an enclosed space, thereby enhancing overall energy utilization without requiring additional power input. The proposed system integrates the AWG exhaust outlet with a heat exchanger, enabling effective thermal exchange between the cold dehumidified air and the recirculated cold room air. This configuration maintains a sub-ambient temperature within the enclosed space while the AWG unit continues potable water production. Experimental investigations demonstrated that the integrated system could achieve a temperature at least 10°C lower than the ambient range of 28°C–32°C within a prototype cold room of 22.65 m³ volume. The system produced 195.73 L/day on day 1, with a corresponding specific energy consumption (SEC) of 0.49 kWh/L. On day 2, the water yield was 92.63 L/day, with an SEC of 1.04 kWh/L. These results validate the system's energy efficiency and dual functionality, showcasing its potential for sustainable cold storage applications in water-scarce and warm climatic regions.

In this study, used lubricant oil was recycled using sulfuric acid, soda ash, rosin, and potash alum. The study found that the physicochemical properties of the recovered oil were closely aligned with the properties of fresh oils, indicating that the recycling process via this modified method was effective. The quality of the recycled oil was assessed using various physio-chemical tests, which included evaluating its viscosity, density, pour point, and aniline point. The analysis of the density of the used oil revealed a value of 863.54 kg/m³, whereas the density of the recovered oil sample showed a decrease to 850.26 kg/m³. This implies the treatment process was effective in eliminating the solid heavy impurities from the used oil. Additionally, the chemical composition of the recycled oil was analyzed using Fourier Transform Infrared Spectroscopy (FT-IR) and UV–Visible spectra, which demonstrated that the composition of the recycled oil was similar to that of fresh oil. The FT-IR analysis further revealed the presence of oxidized products in the used oil, which contributed to the oil's contamination. However, the UV analysis confirmed that the recycled oil was free from impurities post-treatment, highlighting the effectiveness of the recycling process.

Textile wastewater contains harmful synthetic dyes, organic contaminants, and toxic chemicals, requiring advanced treatment methods to protect the environment and human health. It is important to find the best way to use new treatment methods for textile wastewater. In order to forecast the textile dye removal effectiveness utilizing the ultrasound-assisted Fenton procedure, this study used machine learning (ML). A test set was used to assess the model's prediction skills after it was developed using a train set. Subsequently, a prediction model was constructed to understand the effect of each feature on remediation efficiency. According to the laboratory experimental results obtained, it was determined that pH 2 was the most suitable value for the most effective removal of organic contaminants in the Fenton process, and it was revealed that pH was the factor with the greatest impact on removal efficiency. The created Linear Regression (LR) model showed promise in forecasting textile dye removal efficiency with the use of the ultrasound-assisted Fenton procedure. The LR model achieved an accuracy score of 0.9265 for removal efficiency, with a Mean Squared Error (MSE) of 90.664, a Mean Absolute Error (MAE) of 7.489, and a Root Mean Squared Error (RMSE) of 9.522. In general, this research would aid in assessing textile dye's remediation capacity and maximize removal efficiency under ideal circumstances.

The limited availability of fossil fuels, which cause serious environmental damage such as the greenhouse effect, global warming, and acid rain, compels people to turn to alternative energy sources. Proton Exchange Membrane (PEM) fuel cells provide high efficiency by converting electrochemical energy into electrical energy without harming the environment. PEM fuel cells stand out due to their high performance at low operating temperatures and their portability. In this study, a single cell PEM fuel cell with a 5 cm² active area and a Nafion 212 membrane was used to conduct experiments at room temperature under constant pressures of 0.5 bar and 2 bar, with temperature increases of 10°C in the range of 60°C to 90°C. The values obtained from the experiments were recorded using precision measuring devices, and the experimental results were analyzed. The analysis revealed that the optimal operating temperature for PEM fuel cells is around 80°C and that performance improves with increased pressure. When the inlet pressure was raised from 0.5 bar to 2 bar, an average performance improvement of 15.98% was observed in the temperature range of 60°C to 90°C.

Secondary effluents are regarded as both sources and sinks of emerging contaminants. Adsorption by activated coke (ACO) is successfully being applied in the advanced treatment of secondary effluent from the wastewater treatment plant of China. However, ACO proved ineffective in removing the sweetener acesulfame (ACE). Herein, both mesoporous ACO and microporous activated carbon (AC) were comparatively used for the innovative confinement of Mn oxides within their porous structures by impregnation/calcination to enhance ACE adsorption. The optimal synthesis conditions were determined to be a MnSO₄·H₂O/ACO mass ratio of 1.0% and a calcination temperature of 600°C (Mn-ACO600). Mn-ACO600 exhibited superior ACE adsorption compared to Mn-modified AC. Stable adsorption performance was observed within the neutral pH range, which favors practical applications. The pseudo-second-order model best described the adsorption kinetics, indicating a possible chemisorption mechanism. Both the Langmuir and Freundlich isotherm models could effectively simulate ACE adsorption, with a q_max of 299.6 mg/g at 298 K. Thermodynamic analysis indicated a spontaneous and exothermic process (ΔH⁰ = −68.51 kJ/mol) with entropy reduction (ΔS⁰ = −218.56 J mol⁻¹·K⁻¹). Both coexisting inorganic anions and natural organic matter had insignificant influences. Furthermore, the recycled Mn-ACO600 retained an acceptable adsorption capability. Three-dimensional fluorescence excitation-emission matrix analysis demonstrated that Mn-ACO600 adsorption effectively removed organic matter from real secondary effluent.

This work aims to experimentally investigate the improvement in the performance and water productivity of a single-basin single-slope solar water distiller system by adding a porous structure (stones) and phase change material (PCM) above the basin surface. To explore the impact of adding a porous structure and PCM, two models are tested. The modified model that uses a porous structure and PCM is called (MSD-FSP), whereas the normal model is called (SD-F). Both systems include fins fixed above the absorber surface. A paraffin wax filled inside tubes as PCM is used with the MSD-FSP model. The experiments are conducted in Mosul City, Iraq, during November and December 2023. The MSD-FSP model is tested with only PCM and PCM with stones. The findings obtained from MSD-FSP and SD-F are compared under various water depths. The results showed that the MSD-FSP model is more effective than the SD-F model, where the performance of the MSD-FSP is higher than the SD-F by 31% for 30 mm water depth and 27% for 50 mm water depth. The findings also observed that the water productivity of the MSD-FSP model is larger than that of the SD-F model by 35% (for 30 mm water depth) and 28% (for 50 mm water depth). The findings indicated that the highest water temperature and water productivity are achieved while using the MSD-FSP model, and these values are equal to 49.8°C and 0.81 kg/m² at a water depth of 30 mm. The results confirm that using a porous structure (stones) and PCM has considerable impacts on heat exchange, evaporation rate, and heat transfer and hence, improves system performance.