Abstract Water pollution remains a significant environmental challenge in the contemporary era, largely attributed to the widespread use of synthetic dyes in textile industries and the discharge of pathogens such as Escherichia coli (E. coli) into nearby water bodies. These organic and microbial contaminants pose various health risks, including but not limited to carcinogenic threats, reproductive issues, skin allergies, and other potential health hazards. Addressing this issues, recent efforts have focused on leveraging waste management strategies and geochemical water pollution control approaches, particularly through the photodegradation process, to eliminate different types of contamination from wastewater. This study employed a green synthesis method to produce tea waste hydrochar (TWH) through a hydrothermal process at 180˚C for 10 h. Characterization of the TWH involved techniques such as XRD (X-ray Diffraction), SEM (scanning electron microscopy), and FTIR (Fourier-Transform Infrared Spectroscopy). Subsequently, the synthesized TWH was utilized to eliminate dye-based contamination from both pure (Milli Q water) and river-based water under UV light irradiation. The experimental findings revealed remarkable photodegradation efficiency, as methylene blue (MB) dye achieved 90% degradation in pure water and 75% degradation in river-based water within 3 h under UV light irradiation. Moreover, the TWH exhibited excellent antibacterial action in removing E. coli bacteria from river water achieved 99.64% removal efficiency under UV light irradiation. These results confirm TWH offers dual-functionality, cost-effective and greener approach for wastewater treatment, particularly in the organic contaminants degradation and antimicrobial activities, and help to achieve the Sustainable Development Goals (SDG 6: Clean water and sanitation) of the United Nations.
Radio frequency (RF) energy harvesting (EH) for wireless networks offers a green and sustainable solution, enhancing energy efficiency and ensuring the longevity of devices, even in remote, inaccessible locations. Such RF-EH mechanisms are utilized in simultaneous wireless information and power transfer systems. This study evaluates wireless information and power transfer in two-way relay networks, where two source nodes communicate directly and via a battery-powered relay node. This research presents new analytical results assuming the time switching protocol with amplify-and-forward relaying, and selection combining receiver to combine direct-link and relay-assisted signals over generalized η -μ fading channels. Our study derives novel analytical formulations for key performance measures, namely outage probability, system throughput, system energy efficiency, and the average symbol error rate of a generalized rectangular quadrature amplitude modulation scheme. In addition, an asymptotic analysis of the outage probability is carried out to determine the diversity order of the system. The resulting expressions are formulated as rapidly converging infinite series, which can be efficiently evaluated using only a limited number of terms. The influence of key system parameters, such as fading characteristics, target rate threshold, time switching ratio, energy conversion efficiency, relay location, and constellation order, is thoroughly examined. The accuracy of the proposed analytical framework is verified through numerical evaluation and Monte Carlo simulations, demonstrating excellent agreement between analytical and simulation results.
This study is conducted to update Tropical Summer Index (TSI), the first thermal comfort model of the Indian subcontinent, which was developed in 1983 by studying 18 male subjects in a static environment. Researchers carried out a year-round study in 22 residential buildings in five different cities within the Indian composite climate during the monsoon, winter, and summer seasons. To update TSI and propose a-TSI, 2274 observations were collated in the morning, evening, midday, and night, where subjects had access to various adaptive actions. The CEN EN 15251 approach is applied to evaluate comfortable temperatures, and the ASHRAE 55 methodology is used to determine neutral and preferred temperatures. Correlation and multiple regression analysis, as per TSI, are used to propose a-TSI. Eighty-four percent of participants reported feeling comfortable at a preferred and comfortable temperature of 24.3 degrees C and 26.2 degrees C, respectively, and a widely adaptive comfort range of 18.2 degrees C - 34.7 degrees C. A steeper adaptive slope of 69.94% indicates that the subjects' contextual adaptation to environmental influences is high. The proposed a-TSI is verified by comparing it with other Indian residential sector thermal comfort studies as well as the TSI, IMAC, IMAC-R, ASHRAE, and CEN adaptive thermal comfort models. a-TSI is an essential adaptive model that helps understand the prevalent thermal comfort requirements of Indian subjects.
This study aims to redefine the role of green buildings (GB) in sustainable urban design by integrating deep learning (DL)-based fa & ccedil;ade segmentation and Internet of Things (IoT)-driven environmental information. The study's specific objectives are to (i) create a precise DL framework for extracting fa & ccedil;ade characteristics, and (ii) combine these visual insights with IoT-based air quality metrics to comprehend their collective impact on healthy and sustainable urban settings. A U-Net segmentation architecture is utilized to analyze fa & ccedil;ade properties, while addressing class imbalance challenges in the open-access dataset through six data augmentation procedures. Two DL models are proposed-Model-I (baseline) and Model-II (enhanced)-and evaluated on both the original fa & ccedil;ade dataset and a newly generated edge-enhanced dataset. Model-II shows better performance, with a segmentation accuracy of 0.98. In addition to segmentation, the study examines how the architecture of a building's fa & ccedil;ade impacts air quality in cities and the performance of microclimates. The research demonstrates that integrating fa & ccedil;ade conditions with real-time IoT air-monitoring data can enhance ventilation, diminish pollutant exposure, and facilitate climate-resilient design through optimized fa & ccedil;ade layouts. The results show that using DL-enabled facade analysis, along with feedback from the environment, can help architects and city planners create buildings and cities that are energy-efficient, low-carbon, and beneficial to people's health.
For better exciton separation and high catalytic activity, the most trailblazing stratagem is to frame S-scheme heterojunction photocatalytic systems through a simple repeatable synthetic strategies. In context to the above, a solvothermal followed by thermal annealing method was developed to convert type-II g-C3N4/MIL-53 (Fe) (g-C3N4/ML) into nanostructured S-scheme g-C3N4/Fe2O3 (g-C3N4/FO) under N2 atmosphere at 500 degrees C. During the thermal annealing process of g-C3N4/ML, as revealed from the XRD, Raman, TEM, and XPS analysis, the MOF structures of MIL-53 (Fe) (ML) were destroyed. They were transformed to g-C3N4/FO with a thin layer of amorphous carbon around the developed alpha-Fe2O3 (FO) nanoparticles. The intercalated carbon between the g-C3N4 nanosheets and FO nanoparticles functions as an electron donor/acceptor, which converts g-C3N4/ML type-II heterojunction to g-C3N4/FO S-scheme heterojunction. When the photocatalytic activity of the developed nanocatalysts are scrutinized, it shows outstanding photocatalytic performance, which is 4.1, 2.9 and 4.5 folds times higher than g-C3N4/ML for bromoxynil degradation (97.3 %), As(III) oxidation (93.35 %), and H2 evolution (5336.53 mu mol g-1 h-1) reactions under visible light. It is also observed from the cytotoxicity studies that the obtained photocatalyst degraded toxic bromoxynil pesticide into non-toxic byproducts. This amplified photocatalytic activity can be attributable to the change in spatial charge carrier migrations from type-II to Sscheme followed by superior light absorption capacity and improved separation efficiency of the photogenerated charge carriers.
