Environmental Progress & Sustainable Energy最新文献

Solar thermal collectors, such as evacuated tube collectors (ETCs), are essential for harnessing renewable energy, yet their efficiency is often hindered by thermal losses and limited heat transfer. This study focuses on enhancing ETC performance for seawater desalination by using nanofluids as heat transfer fluids. These modifications aim to improve heat transfer rates, reduce thermal losses, increase the maximum temperature attainable, and minimize the collector area required. An experimental setup has been developed at Parul University in Vadodara, Gujarat, India. Key parameters such as air mass flow rate, inclination angle, water mass flow rate, nanofluid volume percentage, and screw conveyor speed were optimized to achieve ideal temperature levels. Results indicate that the optimal configuration for steam generation includes a high air mass flow rate and a 40° inclination angle for the ETC. Additionally, a water mass flow rate of 10 LPH and a screw conveyor speed of 30 rpm are crucial for optimal performance. Data collected showed the highest solar energy levels between 12 PM and 1 PM, which significant decreases post this peak period. These findings highlight the potential of nanomaterial-based enhancements in improving the efficiency and cost-effectiveness of solar thermal systems for renewable energy applications.

Many factors determine the percentage of parasitic load of the geothermal power plant. Domestic consumption accounts for about 20–25 per cent of total production in low-temperature geothermal power plants. As a case study, the ratio of a 1 MW grid-connected PV system to the internal consumption of the Sultanhisar GPP-2 and its effect on increasing the efficiency of the system have been examined. The current production of the power plant has been modeled thermodynamically with the parameters taken from the plant, and the efficiency of the system has been calculated. Sultanhisar GPP-2, which operates at a geothermal well temperature of 140.2°C and a net efficiency of 6.28%, has a domestic consumption to production ratio of around 25%. The installation of a 1 MW PV system is expected to produce 2140MWh per year, equivalent to 7% of the internal energy consumption.

This study was conducted for the first time to discern the levels of primary aromatic amines (PAAs) in hookah wastewater resulting from the consumption of fruit-flavored and traditional tobacco. The ecological risk of PAAs laden hookah wastewater and its toxic effects on crustaceans and fish have also been evaluated. The mean concentrations of PAAs in hookah wastewater resulting from consumption of Al-Mahmoud, Al-Ayan, Al-Fakher, and Mazaya brands were 1075.56, 1033.25, 986.94, and 946.58 ng/L, respectively, while it was determined as 355.91 ng/L in traditional tobacco. The concentration of PAAs in the hookah wastewater of fruit-flavored tobacco was significantly higher than the traditional one (p < 0.05). Aniline (ANL) had the maximum level in hookah wastewater from fruit-flavored (679.83–802.50 ng/L) and traditional (316.53 ng/L) tobacco consumption. The RQ value of the mean concentration of PAAs in hookah wastewater for all samples was in the range of medium to low-risk (RQ < 1). In addition to PAAs, other dangerous chemicals in hookah wastewater can increase its ecological and health risk, so it is necessary to manage such wastewater before discharging it into the environment.

Rice husk silica (RHS) has emerged as a sustainable alternative to traditional sources of silica in various applications, offering eco-friendly attributes, cost-effectiveness, and versatility. This review explores the potential of RHS as a substitute for conventional silica sources, highlighting its alignment with sustainable development objectives and its appeal to industries seeking environmental responsibility. Among the extraction methods, acid leaching is identified as yielding higher purity silica. In contrast, among the novel techniques, the hydrothermobaric process stands out for producing high purity and yielding nanosilica. Despite challenges like limited access to high-quality rice husks and variations in silica content, RHS extraction methods show promising avenues for sustainable silica production, addressing waste management, and environmental concerns. Further development and optimization of extraction techniques are essential for widespread acceptance, with future research focusing on nanoparticle synthesis and incorporating green chemistry principles. This comprehensive review of RHS provides a valuable resource for researchers seeking to explore sustainable alternatives in their respective fields, aiming to foster adopting more sustainable practices and materials across various industries.

To reduce knock and keeping low NOx emissions and high indicated thermal efficiency (ITE) in a hydrogen fuel engine, the comprehensive effects of ammonia substitution rate (ASR), compression ratio (CR), and ignition timing (IT) on its combustion and its NOx emissions were studied numerically. Based on a four-cylinder gasoline direct injection (GDI) engine, it was modified into an ammonia/hydrogen dual-fuel (AHDF) spark ignition (SI) engine. The simulation was conducted by GT-Power software, and simulation data were validated through experiments. 2500 rpm_50% load was selected for the research. ASR, CR and IT vary from 0% to 20%, 10.5 to 8.5, and −24 to 0°CA ATDC, respectively. The findings indicate that increasing ASR decreases the maximum pressure rise rate (MPRR) and the knock index (KI), improving the ITE, but increasing NOx emissions. Based on 20% ASR, CR was optimized. The findings indicate that decreasing CR reduces the MPRR and KI, but increasing NOx emissions and decreasing the ITE. Finally, based on CR of 9, IT was optimized. The findings indicate that delaying IT reduces the MPRR and KI, but also has a certain impact on NOx emissions and ITE. After compromise consideration, the optimal IT in this study was selected as −9°CA ATDC.

Microbial fuel cell (MFC) is a bioelectrochemical-based reactor that can generate electrical energy directly from wastewater by utilizing microbial activity that oxidizes the waste organic matter. This study aims to synthesize polyaniline (PANI) and deposit on a graphite carbon electrode (GCE) and activated carbon cloth (ACC) surface to use as an anode material for MFCs. The MFC performance was evaluated using oxygen and ferricyanide as electron acceptors. PANI was electropolymerized from its aniline monomer and deposited using an electrophoretic deposition method onto the electrode surface. A PANI thin film was characterized using FTIR, field emission scanning electron microscopy (FESEM), BET, and electrochemical analysis. The analysis results show the characteristic peaks of PANI at 1557 cm⁻¹, demonstratinjg the existence of quinoid rings (NQN), while the peaks at 1479 and 1400 cm⁻¹ corresponding to the benzenoid (NBN) stretching in the PANI structure. The FESEM analysis confirmed that PANI appeared to have a porous structure on modified electrodes. It was found that the best system was MFC with ferricyanide as the electron acceptor. The highest power density produced is 254 mWm⁻² from GCE-PANI and 16.47 mWm⁻² from ACC-PANI. The normalized energy recovery of GCE-PANI and ACC-PANI in ferricyanide is 0.115 kWh kgCOD⁻¹ and 5.67 × 10⁻³ kWh kgCOD⁻¹, respectively. The COD removal was observed to be 88.8% for GCE-PANI and 87.2% for ACC-PANI from 1000 mg/L COD.