The excessive excretion of antibiotics in wastewater poses significant environmental risks. Adsorption is expected as highly efficient, cost-effective, and sustainable methods for treating these contaminants. This study investigated the adsorption of tetracycline hydrochloride (TC) on palm shell derived activated carbon (PSAC) using the advanced pore volume and surface diffusion model (PVSDM). Scanning electron microscopy and N2 adsorption isotherm revealed a highly microporous PSAC with a specific surface area of 852.85 m2 g-1, an average pore diameter of 2.068 nm and a micropore proportion of 0.72. In the developing PVSDM, conventional isotherms (e.g. Langmuir, Freundlich and Redlich-Peterson) and global kinetics models (e.g. pseudo-first order, pseudo-second order and Elovich) were comprehensively analyzed and the most suitable isotherm and global kinetics models were incorporated into the PVSDM. External film diffusion and intraparticle diffusion (IPD) investigation, according to Weber-Morris and Boyd, consistently confirmed strong IPD control. The PVSDM effectively reproduced time-dependent adsorption capacity in batch experiment and was verified by reasonable prediction of the dynamic change of adsorption capacity within the PSAC particle. The determined mass transfer parameters indicated that pore volume diffusion was the dominant mechanism, while surface diffusion was insignificant. This study demonstrates the effectiveness of PVSDM for quantifying mass transfer resistances in adsorption of TC on PSAC, providing valuable insights for the design and optimization of large-scale adsorption equipment for treatment of antibiotics in wastewater.
Acetone is categorized as a volatile organic compound (VOC) gas. Exposure to it for a long period harms human health and the environment. Commonly, a single sensor is used to sense the target gas. However, it always suffered from low selectivity, making it difficult to analyze and differentiate various gases. To overcome this problem, a gas sensor array is proposed in this work to investigate the response value for each array to the acetone vapor. Six sensor arrays based on various ratios of TiO2 doped with graphene were deposited using the screen-printing technique on an FR3-printed circuit board (PCB). The gas sensor arrays were exposed to two different concentrations of acetone vapor at room temperature. Next, the response values were classified using a deep neural network (DNN). The results revealed that the T95_G5 gas sensor responds more to 25 mL and 35 mL of acetone gas, with 1.0966 and 1.2074, respectively. The overall DNN accuracy for acetone vapor was 82.70%.
Using a traditional solid-state mixed oxide method, pelletized polycrystalline zinc oxide-based varistor ceramics were prepared with calcium titanate (CaTiO3) doping. This study examined how varying sintering temperatures affect the microstructural and electrical characteristics of the composite varistors. The samples were subjected to sintering temperatures between 1100 and 1300 °C for 90 minutes. X-ray diffraction (XRD) assessment confirmed the presence of two primary phases in the synthesized compound. Scanning electron microscopy (SEM) results showed that higher sintering temperatures promoted ZnO grain growth, increasing the average grain size from 4.66 to 10.42 µm. The average relative density of the synthesized samples exceeded 94% of the theoretical density. These results were determined to correspond with the modification in electrical properties, as the specimen sintered at 1250 °C demonstrated the most favorable electrical response, of which the nonlinear coefficient, breakdown voltage, and barrier height were 3.85, 0.99 V/mm, and 0.66 eV, respectively. The study presented in this paper can be used to discover and develop new and more efficient ZnO suppressors.
Rammed earth blocks (REBs) are attracting renewed attention as sustainable building materials due to their low embodied energy and use of locally sourced soil, yet their limited tensile strength and moisture sensitivity restrict wider structural applications. This study investigates a dual enhancement approach, combining natural jute fiber reinforcement (0.25–1.25% by weight) with 10% Limestone Calcined Clay Cement (LC3) stabilization. To evaluate performance, mechanical tests—including compaction, compressive strength (dry and wet), flexural strength, ultrasonic pulse velocity (UPV), and water absorption—were performed. Microstructural evolution was examined through binocular microscopy, FESEM-EDS, XRD, and TGA analyses. Results indicated that 1% jute fiber provided the best balance of strength and ductility, while LC3 contributed to matrix densification and improved durability. The combined system achieved a compressive strength of 4.32 MPa, a flexural strength of 1.17 MPa, and reduced water absorption to 13.18%. Microstructural observations confirmed the formation of pozzolanic products and a refined pore network, highlighting the potential of this composite for durable, low-carbon, and cost-effective construction.
Edible oil adulteration significantly challenges food safety, nutritional quality, and consumer trust. This review explores the advancements in detection technologies, focusing on highly sensitive methods such as spectroscopy-based methods (UV-VIS, NIR, Raman, SERS), fluorescence-based methods, optical fiber sensors, and colorimetric approaches. These innovations leverage nanotechnology in optical sensing to improve the accuracy, sensitivity, and real-time applicability of adulteration detection. Spectroscopy methods like Raman and NIR offer molecular fingerprinting, while portable fluorescence and colorimetric systems provide cost-effective, on-site solutions. Despite these advances, challenges such as method standardization, affordability, and compatibility with diverse adulterants remain. The review underscores the critical role of integrating advanced sensing technologies to ensure food authenticity, enhance consumer protection, and uphold industry standards.
