ChemEngineering

21 pages, 3414 KiB

Open AccessArticle

Oxalic Acid-Assisted Photo-Fenton Catalysis Using Magnetic Fe₃O₄ Nanoparticles for Complete Removal of Textile Dye

by Sunil Bhavsar, Pravin Dudhagara, Anjana Ghelani, I Nengah Wirajana, Quyet-Tien Phi, Yih-Yuan Chen and Douglas J. H. Shyu

ChemEngineering 2024, 8(4), 67; https://doi.org/10.3390/chemengineering8040067 - 28 Jun 2024

Viewed by 151

Abstract

Textile industry effluents contain several hazardous substances, such as dye-containing effluents, which pose environmental and aesthetic challenges. Presently, the microbial-based remediation process is in use. This study investigated the application of ferrous–ferric oxide (Fe₃O₄) nanoparticles, a readily formulated nanoadsorbent, to remove scattered dye molecules from industrial effluents. The ferrous–ferric oxide nanoparticles were prepared using a chemical co-precipitation method. The nanoparticles had 26.93 emu g⁻¹ magnetization, with sizes smaller than 20 nm, and possessed a highly purified cubic spinel crystallite structure. The catalytic activity of the iron oxide depended on the dose, photocatalytic enhancer, i.e., H₂O₂ level, pH of the reaction medium, and dye concentration. We optimized the Fenton-like reaction to work best using 1.0 g/L of ferrous–ferric oxide nanoparticles, 60 mM oxalic acid at pH 7.0, and 60 ppm of dye. Iron oxides act as photocatalysts, and oxalic acid generates electron–hole pairs. Consequently, higher amounts of super-radicals cause the rapid degradation of dye and pseudo-first-order reactions. Liquid chromatography–mass spectrometry (LC-MS) analysis revealed the ferrous–ferric oxide nanoparticles decolorized and destroyed Disperse Red 277 in 180 min under visible light. Hence, complete demineralization is observed using a photo-Fenton-like reaction within 3 h under visible light. These high-capacity, easy-to-separate next-generation adsorption systems are suggested to be suitable for industrial-scale use. Ferrous–ferric oxide nanoparticles with increased adsorption and magnetic properties could be utilized to clean environmental pollution. Full article

(This article belongs to the Special Issue The Synthesis, Characterization, and Application of Novel Photocatalytic Materials)

41 pages, 7005 KiB

Open AccessReview

Supramolecular Sensing Platforms: Techniques for In Vitro Biosensing

by Hiya Lahiri and Kingshuk Basu

ChemEngineering 2024, 8(4), 66; https://doi.org/10.3390/chemengineering8040066 - 28 Jun 2024

Viewed by 145

Abstract

Supramolecular chemistry is a relatively new field of study that utilizes conventional chemical knowledge to produce new edges of smart materials. One such material use of supramolecular chemistry is the development of sensing platforms. Biologically relevant molecules need frequent assessment both qualitatively and quantitatively to explore several biological processes. In this review, we have discussed supramolecular sensing techniques with key examples of sensing several kinds of bio-analytes and tried to cast light on how molecular design can help in making smart materials. Moreover, how these smart materials have been finally used as sensing platforms has been discussed as well. Several useful spectroscopic, microscopic, visible, and electronic outcomes of sensor materials have been discussed, with a special emphasis on device-based applications. This kind of comprehensive discussion is necessary to widen the scope of sensing technology. Full article

24 pages, 5955 KiB

Open AccessArticle

Enhancement in Turbulent Convective Heat Transfer Using Silver Nanofluids: Impact of Citrate, Lipoic Acid, and Silica Coatings

by Wasurat Bunpheng and Ratchagaraja Dhairiyasamy

ChemEngineering 2024, 8(4), 65; https://doi.org/10.3390/chemengineering8040065 - 26 Jun 2024

Viewed by 418

Abstract

This study aims to investigate the thermohydraulic performance of silver nanofluids with different surface modifications (citrate, lipoic acid, and silica) in turbulent convective heat transfer applications. Three silver nanofluids were prepared, each modified with citrate, lipoic acid, or silica coatings. The nanofluids were characterized for stability using zeta potential measurements and evaluated in a smooth brass tube under turbulent flow conditions. The experimental setup involved measuring the temperature, pressure, and flow rate to assess heat transfer coefficients, pressure drops, and friction factors. The results were compared with distilled water as the base fluid and validated against theoretical models. The silica-shelled nanofluid (Ag/S) exhibited a significant 35% increase in the average heat transfer coefficient compared to distilled water, while the citrate-coated (Ag/C) and lipoic acid-coated (Ag/L) nanofluids showed slight decreases of approximately 0.2% and 2%, respectively. The Ag/S nanofluid demonstrated a 9% increase in the mean Nusselt number, indicating enhanced heat transfer capabilities. However, all modified nanofluids experienced higher pressure drops and friction factors than the base fluid, with the Ag/S nanofluid showing the highest increase in viscosity (11.9%). Surface modifications significantly influence the thermohydraulic performance of silver nanofluids. The silica-shelled nanofluid shows the most substantial enhancement in heat transfer, making it a promising candidate for applications requiring efficient thermal management. However, the increased hydraulic costs associated with higher-pressure drops and friction factors must be carefully managed. Further research is needed to optimize these nanofluids for specific industrial applications, considering long-term stability and the effects of different nanoparticle concentrations and geometries. Full article

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22 pages, 610 KiB

Open AccessReview

Green Synthesis of Silver Nanoparticles from Cannabis sativa: Properties, Synthesis, Mechanistic Aspects, and Applications

by Fatemeh Ahmadi and Maximilian Lackner

ChemEngineering 2024, 8(4), 64; https://doi.org/10.3390/chemengineering8040064 - 21 Jun 2024

Viewed by 434

Abstract

The increasing global focus on green nanotechnology research has spurred the development of environmentally and biologically safe applications for various nanomaterials. Nanotechnology involves crafting diverse nanoparticles in terms of shapes and sizes, with a particular emphasis on environmentally friendly synthesis routes. Among these, biogenic approaches, including plant-based synthesis, are favored for their safety, simplicity, and sustainability. Silver nanoparticles, in particular, have garnered significant attention due to their exceptional effectiveness, biocompatibility, and eco-friendliness. Cannabis (Cannabis sativa L.) has emerged as a promising candidate for aiding in the green synthesis of silver nanoparticles. Leveraging the phytochemical constituents of Cannabis, researchers have successfully tailored silver nanoparticles for a wide array of applications, spanning from biomedicine to environmental remediation. This review explores the properties, synthesis mechanisms, and applications of silver nanoparticles obtained from Cannabis. Additionally, it delves into the recent advancements in green synthesis techniques and elucidates the optical properties of these nanoparticles. By shedding light on plant-based fabrication methods for silver nanoparticles and their diverse bionanotechnology applications, this review aims to contribute to the growing body of knowledge in the field of green nanotechnology. Through a comprehensive examination of the synthesis processes, mechanistic aspects, and potential applications, this review underscores the importance of sustainable approaches in nanoparticle synthesis and highlights the potential of Cannabis-derived silver nanoparticles in addressing various societal and environmental challenges. Full article

(This article belongs to the Special Issue Advanced Chemical Engineering in Nanoparticles)

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ChemEngineering, Volume 8, Issue 4 (August 2024) – 4 articles

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