2026-02-03
Fayaz Keerio, Ambreen Shah, Mohammad Younis Talpur
Bimetallic complexes have garnered significant attention in the scientific community due to their versatile applications, such as antibacterial, antifungal, antitubercular, antimalarial, antioxidant, antibiotic, anti-inflammatory, and anticancer activities. This study reports the synthesis and characterization of a bimetallic Zn/Ni complex derived from 2,2’-bipyridine-4,4’-dicarboxylic acid (BPyCOOH) as a multifunctional coordination compound with effective antimicrobial impact. This complex ensured efficient coordination of the ligand with both Zn(II) and Ni(II) ions due to its bifunctional groups in a single ligand structure. Structural elucidation was achieved through UV–Vis, FTIR, and elemental analyses. The UV–Vis spectrum displayed two distinct absorption bands at approximately 280 nm and 400 nm, attributed to π–π* transitions and metal-to-ligand charge transfer (MLCT), confirming the successful formation of the bimetallic coordination framework. The Zn/Ni(BPyCOOH)₂ complex was evaluated for its antimicrobial potential against selected Gram-positive and Gram-negative bacterial strains, also demonstrating minimum inhibitory concentration (MIC) activity. The Gram-positive bacteria, P. mirabilis, showed the highest zones of inhibition (27.7±0.9) at (20 mg/ml) of Zn/Ni(BPyCOOH)₂ complex. Therefore, Zn/Ni(BPyCOOH)₂ complex shows concentration (dose) dependent antimicrobial activity. It is most effective against Proteus mirabilis (P. mirabilis), gram-negative, and least in Staphylococcus aureus (S. aureus), gram-positive, by calculating the diameter of the zone of inhibition. No inhibition observed in the control, which proves the results are valid.
2026-01-15
Amna Azam, Ali Husnain, Ali Sarosh, Sabih Qamar, Uzair Shamas, Asim Umer
The Industrial release of synthetic dyes, such as methylene blue (MB), into water has created significant environmental concerns. The use of date trunk as a bio-adsorbent was investigated for the removal of MB dye from wastewater. The effects of several experimental parameters, such as MB dye concentration, contact time, and adsorbent dosage, were studied using a batch-laboratory operational setup. Fourier Transform Infrared (FTIR) spectroscopy was performed to reveal the presence of functional groups in the bio-adsorbent. This study evaluated the adsorption capacity of a green bio-adsorbent for the removal of MB dye from wastewater. The maximum adsorption of MB was obtained for the bio-adsorbent dosage of 0.4 gram for 50 min, achieving a maximum removal efficiency of 92.4%. The Gaussian 09 software package was used for Density Functional Theory (DFT) to optimize the molecular structures of guaiacol and methylene blue (MB) dye, , with the calculated adsorption energy (E ads = -1.43 Hartree) confirming a thermodynamically favorable interaction. The results revealed that date trunks have great potential as efficient bio-adsorbents for the removal of MB dye from wastewater.
2025-10-24
Farshad Farahbod, Abuzar Shakeri, Seyede Nasrin Hosseinimotlagh
The present study investigates the desulfurization of heavy and light crude oils using ferric-oxide (Fe₂O₃) nano-catalysts under mild operating conditions, with the goal of developing an energy-efficient, hydrogen-free alternative to conventional hydrodesulfurization (HDS). Laboratory experiments were conducted in a fixed-bed catalytic reactor, evaluating the effects of temperature (35–75 °C), pressure (1.0–1.9 bar), catalyst particle diameter (54–91 nm), and catalytic-bed diameter (1–2.5 cm) on sulfur-removal efficiency. Optimal desulfurization occurred at 55 °C, 1.6 bar, and a bed diameter of 2.5 cm, with 58 nm and 77 nm nanoparticles showing the best performance for heavy and light crudes, respectively. A quadratic regression model developed through analysis of variance (ANOVA) yielded an excellent fit (R² = 0.9997, Adj-R² = 0.9899), validating the model’s predictive capability. Compared with conventional HDS, the Fe₂O₃ nano-catalyst achieved 70–90 % sulfur removal without hydrogen consumption and at less than one-tenth of the energy intensity. A preliminary techno-economic analysis indicated that the heating energy accounts for ~45 k USD yr⁻¹ (≈0.1 kWh kg⁻¹ S removed) for a 1,000 bbl day⁻¹ pilot system. Benchmarking against HDS, oxidative desulfurization (ODS), and bio-desulfurization (BDS) demonstrated the potential of the nano-catalyst process for decentralized or small-scale refinery units. The findings provide a foundation for scaling up low-pressure, low-temperature catalytic desulfurization systems and integrating them with sustainable refining operations.