Next Issue
Volume 8, October
Previous Issue
Volume 8, June
 
 

ChemEngineering, Volume 8, Issue 4 (August 2024) – 20 articles

Cover Story (view full-size image): Supramolecular chemistry is a comparatively newer field, leveraging traditional chemical techniques to create advanced molecular machines with enhanced functionalities. One of the major applications of this field is to sense biologically derived molecules quickly and accurately to understand the key biological processes. This review highlights the power of supramolecular chemistry to craft smart materials that can sense bio-analytes efficiently. Also, it describes a recent development, namely the conjunction of molecular science and cutting-edge device technology to create user-friendly sensing platforms. View this paper
  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Select all
Export citation of selected articles as:
16 pages, 2861 KiB  
Article
Parametric Optimization of Multi-Stage Flashing Desalination System Using Genetic Algorithm for Efficient Energy Utilization
by Khalideh Al bkoor Alrawashdeh, La’aly Al-Samrraie, Abeer Al Bsoul, Ayat Khasawneh, Bashaar Ammary and Eid Gul
ChemEngineering 2024, 8(4), 83; https://doi.org/10.3390/chemengineering8040083 - 19 Aug 2024
Viewed by 1225
Abstract
The technique of multi-stage desalination with brine recirculation (MSF-BR) is characterized by its high energy demand, necessitating the exploration of efficient operational methods to minimize energy consumption and enhance plant performance. In this research study, Matlab R2021a software was used to apply a [...] Read more.
The technique of multi-stage desalination with brine recirculation (MSF-BR) is characterized by its high energy demand, necessitating the exploration of efficient operational methods to minimize energy consumption and enhance plant performance. In this research study, Matlab R2021a software was used to apply a genetic algorithm with the aim of determining the optimal values of the operating variables of the MSF-BR system within certain limits, considering energy consumption and feed seawater temperature variation. The study included improving several operational factors, including top brine temperature, steam temperature, feed seawater temperature, cooling water flow rate and make up flow rate, number of station stages, and the stages of the heat rejection section. The optimal maintenance period during the operational year was also determined. The results of the analysis were based on data from the Al-Khafji desalination plant, which consists of 16 stages and has a production capacity of 7,053,393.8 gallons/day. The study aimed to achieve two main objectives: increasing the gain output ratio (GOR) and reducing the proportion of the recovery ratio. The results showed that the optimal period for maintenance is January, where the performance ratio ranges between 0.987 and 9.38, compared to the currently used month of December, where the performance ratio ranges between 1.096 and 9.56. Optimal target values were set at the following operating parameters: 33.3 °C for feed seawater temperature, 98.67 °C for steam temperature, 95.62 °C for brine temperature, 1571.18 kg/s for cooling water flow rate, 1624.24 kg/s for feed water flow rate, 21 stages for the station, and two stages for the heat rejection section. To achieve the highest GOR, the number of stages and heat rejection section should be more than 19 and 2, respectively. In general, to achieve improvements in GOR and reduce energy consumption, it is recommended to maintain Tf in the range of 33–34 °C and set Mcw between 1050 and 1800 kg/s. Full article
(This article belongs to the Special Issue Advances in Renewable Energy Derivatives)
Show Figures

Figure 1

32 pages, 3209 KiB  
Review
Reverse Polarity-Based Soil Electrokinetic Remediation: A Comprehensive Review of the Published Data during the Past 31 Years (1993–2023)
by Ahmed Abou-Shady and Heba El-Araby
ChemEngineering 2024, 8(4), 82; https://doi.org/10.3390/chemengineering8040082 - 15 Aug 2024
Cited by 2 | Viewed by 1034
Abstract
Soil restoration by exploiting the principles and basics of electrokinetic (EK) has been extended to involve several categories, such as electrokinetic remediation in soil (SEKR), soil consolidation, the prevention of soil pollution, reclaiming salt-affected soil, the dewatering/dryness of wet soils, water reuse, seed [...] Read more.
Soil restoration by exploiting the principles and basics of electrokinetic (EK) has been extended to involve several categories, such as electrokinetic remediation in soil (SEKR), soil consolidation, the prevention of soil pollution, reclaiming salt-affected soil, the dewatering/dryness of wet soils, water reuse, seed germination, sedimentation, etc. As an extension of our recently published review articles on the soil electrokinetic (SEK) process intensification/optimization, the present review illustrates the effect of a reverse-polarity mode (RPM) on the efficiency of the SEK. Based on several searches of six database search engines, we did not find any relevant reviews focused on SEK improvements using the RPM. The influences of the RPM are described by various features, including (a) pollutant removal (organic, inorganic, and mixed pollutants) and (b) integration with other processes (phyto/bioremediation and Fenton oxidation), geosynthetics (consolidation, stabilization, and sedimentation), SEK operation conditions, and soil properties. Most of the RPM studies have focused on the remediation of organic pollutants. Several benefits can be gained from applying the RPM, such as (a) controlling the soil’s temperature, pH, and moisture values at desirable levels, (b) reducing a large number of chemical additives, (c) high remediation efficiency, (d) maintaining the indigenous fungal community’s appropriate diversity and abundance, (e) a stable and higher electric current, (f) enhancing microbial growth, etc. However, the hindrances to applying the RPM are (a) reducing the electroosmosis flow, (b) relatively high energy consumption, (c) reducing the diversity of soil microbes with a prolonged experiment period, (d) providing oxygen for a microbial community that may not be desirable for anaerobic bacteria, etc. Finally, the RPM is considered an important process for improving the performance of the SEK, according to experimental endeavors. Full article
(This article belongs to the Special Issue New Advances in Chemical Engineering)
Show Figures

Figure 1

10 pages, 1801 KiB  
Article
Microstructure and First Hydrogenation Properties of Individual Phases in TiFe + 12 wt.% ZrV2 Alloy
by Daniela Bellon Monsalve, Elena Ulate-Kolitsky, Jorge M. Cubero-Sesin, Alejandro-David Martínez-Amariz and Jacques Huot
ChemEngineering 2024, 8(4), 81; https://doi.org/10.3390/chemengineering8040081 - 12 Aug 2024
Viewed by 961
Abstract
This study investigates the microstructure and first hydrogenation properties of Fe52Ti40Zr3V5 and Fe37Ti44Zr9V10 alloys, which are individual phases present in the as-cast TiFe + 12 wt.% ZrV2 alloy [...] Read more.
This study investigates the microstructure and first hydrogenation properties of Fe52Ti40Zr3V5 and Fe37Ti44Zr9V10 alloys, which are individual phases present in the as-cast TiFe + 12 wt.% ZrV2 alloy (parent alloy). The parent alloy exhibited fast first hydrogenation kinetics due to the interplay of these two phases. Our objective is to study the hydrogen storage behavior of these individual phases. The samples were synthesized by arc melting and characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The results show that when these alloys are melted separately, they do not exhibit the same phase composition as in the parent alloy, indicating a metastable state under our synthesis conditions, which significantly impacts their hydrogen storage behavior. Hydrogenation capacity was measured using a homemade Sieverts apparatus. Both alloys demonstrated excellent first hydrogenation kinetics, with an absorption capacity of 0.9 wt.% for the Fe52Ti40Zr3V5 alloy and 2.3 wt.% for Fe37Ti44Zr9V10 alloy. Our key finding is that the final crystal structure of multi-element alloys is highly dependent on the synthesis method. Full article
Show Figures

Figure 1

16 pages, 4641 KiB  
Article
Synthesis Method Comparison of N-Doped Carbons for Electrochemical Energy Storage
by Roberts Palmbahs, Peteris Lesnicenoks, Ainars Knoks, Virginija Vitola and Janis Kleperis
ChemEngineering 2024, 8(4), 80; https://doi.org/10.3390/chemengineering8040080 - 5 Aug 2024
Viewed by 1006
Abstract
This study investigates nitrogen-doped carbon synthesis and electrochemical properties as electrode material for energy storage devices, an additional focus of the work is on the electrochemical exfoliation synthesis of nitrogen-doped carbon using various precursors and doping methods. The physical properties of the synthesized [...] Read more.
This study investigates nitrogen-doped carbon synthesis and electrochemical properties as electrode material for energy storage devices, an additional focus of the work is on the electrochemical exfoliation synthesis of nitrogen-doped carbon using various precursors and doping methods. The physical properties of the synthesized sample are characterized using X-ray photoelectron spectroscopy, scanning electron microscopy, and Raman spectroscopy. The electrochemical properties of the N-doped carbons are studied using cyclic voltammetry and galvanostatic charge-discharge cycling. Finally, the work explores the potential application of the N-doped carbons as electrode material for energy storage devices, such as supercapacitors. The results show that N-doped carbons exhibit electrochemical performance superior to that of graphene oxide, with higher electrical capacitance. The results demonstrate the potential of N-doped carbons as high-performance electrode materials for electrochemical energy storage applications. This paper aims to explain the advantages of N-doping in carbon materials more precisely in graphene and the use of these materials in creating electrodes for application in supercapacitors and batteries. Full article
(This article belongs to the Special Issue Engineering of Carbon-Based Nano/Micromaterials)
Show Figures

Figure 1

11 pages, 3001 KiB  
Article
Enhanced Oxygen Vacancy Formation in CeO2-Based Materials and the Water–Gas Shift Performance
by Sangaroon Kaewtong, Thanathon Sesuk and Pannipa Tepamatr
ChemEngineering 2024, 8(4), 79; https://doi.org/10.3390/chemengineering8040079 - 2 Aug 2024
Viewed by 963
Abstract
The role of dopants (Sm, Tb and Pr) on the water–gas shift performance of CeO2-based materials was studied. Modification of CeO2 with Sm significantly improved the water–gas shift performance. The catalytic activities of doped CeO2 were increased when compared [...] Read more.
The role of dopants (Sm, Tb and Pr) on the water–gas shift performance of CeO2-based materials was studied. Modification of CeO2 with Sm significantly improved the water–gas shift performance. The catalytic activities of doped CeO2 were increased when compared with the catalytic activities of pure ceria (65% conversion at 600 °C for Ce5%SmO and 50% conversion at 600 °C for CeO2). The key factors driving the water–gas shift performance were reduction behavior and oxygen vacancy concentration. In the redox mechanism of the WGS reaction, CeO2 plays a crucial role in transferring oxygen to CO through changes in the oxidation state. Therefore, Sm is effective in catalyzing the water–gas shift activity because the addition of Sm into CeO2 decreases the surface reduction temperature and alters the oxygen transportation ability through the redox mechanism. XRD results suggested that Mn+ (M = Sm, Tb and Pr) incorporate into ceria lattice to form a solid solution resulting in unit cell enlargement. The defect structure inside the CeO2 lattice generates a strain on the oxide lattice and facilitates the generation of oxygen vacancies. XANES analysis revealed that Sm reduced CeO2 easily by transporting its electron into the d-orbitals of Ce, thus giving rise to more Ce3+ at the CeO2 surface. The presence of Ce3+ is a result of oxygen vacancy. Therefore, the high content of Ce3+ provides more oxygen vacancies. The oxygen vacancy formation results in easy oxygen exchange. Thus, reactive oxygen species can be generated and easily reduced by CO reactant, which enhances the WGS activity. Full article
Show Figures

Figure 1

48 pages, 21855 KiB  
Review
Arsenic in Water: Understanding the Chemistry, Health Implications, Quantification and Removal Strategies
by Muhammad Murtaza Chaudhary, Saqib Hussain, Chenyu Du, Barbara R. Conway and Muhammad Usman Ghori
ChemEngineering 2024, 8(4), 78; https://doi.org/10.3390/chemengineering8040078 - 1 Aug 2024
Viewed by 3676
Abstract
Arsenic, the 20th most common element in Earth’s crust and historically regarded as the King of Poisons, occurs naturally in two oxidation states, Arsenate (V) and Arsenite (III), and is prevalent worldwide through natural and anthropogenic means. The cations of the metalloid exhibit [...] Read more.
Arsenic, the 20th most common element in Earth’s crust and historically regarded as the King of Poisons, occurs naturally in two oxidation states, Arsenate (V) and Arsenite (III), and is prevalent worldwide through natural and anthropogenic means. The cations of the metalloid exhibit unique chemical behaviour in water and are found to be components of approximately 245 natural minerals, making its occurrence in drinking water a compelling challenge, especially in groundwater. This comprehensive review collates information regarding the prevalence of arsenic contamination in water worldwide and its impact on human health, its chemical behaviour, methods for detection and quantification, and treatment strategies. A comprehensive search was conducted, and the selection of eligible studies was carried out using the PRISMA (the preferred reporting items for systematic reviews and meta-analyses) guidelines. Essential characteristics of eligible research studies were extracted based on geographical areas, origins, concentration levels and the magnitude of populations vulnerable to arsenic contamination in groundwater sources. Arsenic contamination of water affects over 100 countries including Canada, the United States, Pakistan, China, India, Brazil and Bangladesh, where hydrogeological conditions favour prevalence and groundwater is the primary water source for food preparation, irrigation of food crops and drinking water. This leads to human exposure through absorption, ingestion and inhalation, causing numerous health disorders affecting nearly all systems within the human body, with acute and chronic toxicity including cancers. The presence of arsenic in water poses a considerable challenge to humanity, prompting scientists to devise diverse mitigation approaches categorized as (a) oxidation processes, (b) precipitation methods, (c) membrane technologies, (d) adsorption and ion exchange methods, and (e) social interventions. This comprehensive review is expected to be a valuable source for professionals in the water industry, public management, and policymaking, aiding their ongoing and future research and development efforts. Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
Show Figures

Figure 1

18 pages, 8014 KiB  
Article
Preparation and Characterization of Supramolecular Bonding Polymers Based on a Pullulan Substrate Grafted with Acrylic Acid/Acrylamide by Microwave Irradiation
by Salam Abdulla Dhahir, Auda Jabbar Braihi and Salih Abbas Habeeb
ChemEngineering 2024, 8(4), 77; https://doi.org/10.3390/chemengineering8040077 - 29 Jul 2024
Viewed by 844
Abstract
A microwave technique was used to prepare a superabsorbent polymer (SAP) by grafting two hydrophilic monomers onto a polysaccharide substrate. The monomers used were acrylic acid (AA) or acrylamide (AM) and were grafted onto a pullulan (PUL) substrate to form PUL-g-AA (SAP1 [...] Read more.
A microwave technique was used to prepare a superabsorbent polymer (SAP) by grafting two hydrophilic monomers onto a polysaccharide substrate. The monomers used were acrylic acid (AA) or acrylamide (AM) and were grafted onto a pullulan (PUL) substrate to form PUL-g-AA (SAP1) and PUL-g-AM (SAP2), respectively. The monomers (AM/AA) were grafted together onto a PUL substrate to form PUL-g-(AM/AA) (SAP3). Grafting parameters such as grafting efficiency with the percentage, the conversion of monomer into polymer, gel content, water retention, water adsorption capacity, and swelling kinetics were determined. Additionally, the effect of environmental pH (2, 4, 7, 9, and 12) and sodium dodecylbenzene sulfonate (SDBS) surfactant was evaluated, where 1, 2, 3, 4, and 5 mM of SDBS was added to form SAP4 to SAP8. The FTIR results show that AM was grafted onto PUL through an aliphatic C-N bond, while AA grafting occurred through a single C-C bond. The grafting efficiency with AM was higher than with AA, as well as showing a superior gel content. Water absorbance capacity and water retention increased with the grafting of AA and AM together for SAP3. The highest absorbent capacity, water retention, gel content, and grafting parameters values were obtained with a 3 mM SDBS content and a pH of 7. The swelling kinetics showed that the increases in the theoretical and experimental swelling equilibriums were 72% and 82%, respectively, for SAP6 compared to the values of these parameters for SAP3. The water absorption capacity of the hydrogel increases upon increasing the pH to 7 and then gradually decreases. XRD demonstrated the improved crystallinity and crystalline size of the hydrogel after grafting polymerization of AM/AA onto PUL, in addition to enhanced thermal stability. On the contrary, FE-SEM demonstrated that SDBS improves the porosity and pore size of the hydrogel surface with SAP6. Full article
(This article belongs to the Special Issue Supramolecular Synthesis in Chemical Engineering)
Show Figures

Figure 1

16 pages, 2177 KiB  
Article
Integration of Ion Exchange—AOP—Biological System for the Treatment of Real Textile Wastewater
by Camila Giraldo-Loaiza, Aura M. Salazar-Loaiza, María A. Sandoval-Barrera, Iván F. Macías-Quiroga, Diana M. Ocampo-Serna and Nancy R. Sanabria-González
ChemEngineering 2024, 8(4), 76; https://doi.org/10.3390/chemengineering8040076 - 26 Jul 2024
Viewed by 1212
Abstract
Real textile wastewater (RTWW) poses significant environmental challenges. RTWW typically contains high levels of organic compounds, such as dyes, as well as inorganic substances like salts. These contaminants can harm aquatic life when released into water bodies without appropriate treatment. RTWW was subjected [...] Read more.
Real textile wastewater (RTWW) poses significant environmental challenges. RTWW typically contains high levels of organic compounds, such as dyes, as well as inorganic substances like salts. These contaminants can harm aquatic life when released into water bodies without appropriate treatment. RTWW was subjected to a series of sequential treatments: exchange resins for removing ions, advanced oxidation with bicarbonate-activated peroxide to degrade organic matter, and a biological treatment based on the Zahn–Wellens test to remove remaining chemical oxygen demand (COD) The advanced oxidation process based on the activation of H2O2 with NaHCO3 (catalyzed with cobalt impregnated on a pillared clay, Co/Al–PILC)) was optimized using central composite design (CCD) and response surface methodology (RSM). After the process integration, reductions in ion concentrations, chemical oxygen demand (COD), and total organic carbon content (TOC) were achieved. Reduced hardness (99.94%) and ions (SO42− and acid black 194 dye of 99.88 and 99.46%, respectively), COD (96.64%), and TOC (96.89%), guaranteeing complete treatment of RTWW, were achieved. Additionally, the biodegradability index of RTWW increased from 0.28 ± 0.01 to 0.90 ± 0.01, and phytotoxicity was reduced, going from a phytotoxic that inhibited the germination of lettuce seeds to a phytostimulant after biological treatment with activated sludge. Full article
Show Figures

Figure 1

16 pages, 4464 KiB  
Article
Visible Light-Driven Photocatalytic CH4 Production from an Acetic Acid Solution with Cetyltrimethylammonium Bromide-Assisted ZnIn2S4
by Monir Uzzaman, Mst. Farhana Afrin, Mai Furukawa, Ikki Tateishi, Hideyuki Katsumata and Satoshi Kaneco
ChemEngineering 2024, 8(4), 75; https://doi.org/10.3390/chemengineering8040075 - 26 Jul 2024
Cited by 1 | Viewed by 983
Abstract
Photocatalytic methods have been popular in energy production and environmental remediation. Designing high-efficiency photocatalysts is still challenging in converting solar energy into chemical fuels. Herein, a series of surfactant-assisted ZnIn2S4 (ZIS) photocatalysts were synthesized by utilizing the one-pot hydrothermal method. [...] Read more.
Photocatalytic methods have been popular in energy production and environmental remediation. Designing high-efficiency photocatalysts is still challenging in converting solar energy into chemical fuels. Herein, a series of surfactant-assisted ZnIn2S4 (ZIS) photocatalysts were synthesized by utilizing the one-pot hydrothermal method. Photocatalytic methane production from an acetic acid solution was carried out under LED light (450 nm) irradiation, and the evolved gas was analyzed by the GC-FID system. Reaction factors (surfactant amount, catalyst dose, reaction temperature, substrate concentration, and reaction pH) were optimized for photocatalytic production. With the increase in cetyltrimethylammonium bromide (CTAB) amount, CH4 production gradually increased. The ZIS-3.75 photocatalyst exhibited the highest photocatalytic CH4 production rate (0.102 µmol g−1·h−1), which was approximately 1.8 times better than that of pure ZIS (0.058 µmol g−1·h−1). The presence of CTAB reduced the charge transfer resistance and improved photocurrent response efficiency. Structure and morphology were characterized by XRD, FTIR, SEM, TEM, and N2 adsorption–desorption isotherm analysis. Optical properties were investigated by UV-DRS and PL spectroscopic techniques. The electrochemical evaluation was measured through EIS, Mott–Schottky, and transient photocurrent response analysis. The CTAB-modified catalyst showed excellent stability and reusability, even after five irradiation cycles. Methane production was enhanced by lowering the photogenerated charge transfer resistance and boosting the dispersion of ZIS-3.75 under visible light (450 nm) irradiation. Full article
Show Figures

Graphical abstract

24 pages, 2444 KiB  
Review
A Critical Review of Macroalgae Exploitation Pathways Implemented under the Scope of Life Cycle Assessment
by Angelos Pantis, Christos Nikoloudakis and Theocharis Tsoutsos
ChemEngineering 2024, 8(4), 74; https://doi.org/10.3390/chemengineering8040074 - 25 Jul 2024
Viewed by 1123
Abstract
Under the umbrella of Blue Economy, research interest is focused on harnessing the potential of macroalgae biomass, known as third-generation feedstock, from which multiple products can be extracted. As many of these exploitation pathways are not yet feasible for large-scale implementation, a significant [...] Read more.
Under the umbrella of Blue Economy, research interest is focused on harnessing the potential of macroalgae biomass, known as third-generation feedstock, from which multiple products can be extracted. As many of these exploitation pathways are not yet feasible for large-scale implementation, a significant number of publications adopt LCA as a tool to assess the sustainability of the proposed value chains. However, the complexity of such systems and the broad spectrum of alternative routes render a vague perspective on the sustainability of such applications. This study provides a critical review of previous research employing LCA to evaluate different pathways of macroalgae utilization. Ethanol, energy (biogas), and nutrition products were found to be among the most studied outputs in the past ten years from an LCA perspective. Different pathways leading to these products were mapped and analyzed, documenting their critical points and proposing measures to mitigate their environmental impact. A thorough SWOT analysis compiles for the first time the scattered information available in the literature, giving insights into the current state of macroalgae use and motives for further research. Insufficient or outdated inventory data for LCA, coupled with technical and technological struggles, were found to be the main barriers to large-scale applications. Full article
Show Figures

Figure 1

17 pages, 4886 KiB  
Article
Valorization of Dextrose from Cassava Starch and Sugarcane Vinasse as Polyhydroxyalkanoates by Submerged Cultures of Cupriavidus necator: A Physicochemical–Biotechnological Approach
by Isabel Dorado, Laura Pineda, Martha L. Ascencio-Galván, Víctor A. López-Agudelo, Julio C. Caicedo, David Gómez-Ríos and Howard Ramírez-Malule
ChemEngineering 2024, 8(4), 73; https://doi.org/10.3390/chemengineering8040073 - 23 Jul 2024
Viewed by 1128
Abstract
The production of polyhydroxyalkanoates using submerged cultures of Cupriavidus necator DSM 428 was evaluated using low-cost substrates from agroindustry: (i) dextrose from cassava starch and (ii) a mixture of sugarcane vinasse from the bioethanol industry and dextrose from cassava starch. The effects of [...] Read more.
The production of polyhydroxyalkanoates using submerged cultures of Cupriavidus necator DSM 428 was evaluated using low-cost substrates from agroindustry: (i) dextrose from cassava starch and (ii) a mixture of sugarcane vinasse from the bioethanol industry and dextrose from cassava starch. The effects of vinasse composition (2.5, 5.0, 7.5, 25, 50, and 75% v/v) and the use of raw and activated carbon-pre-treated vinasse were assessed. The results indicate that cultivations using only cassava starch dextrose reached 4.33 g/L of biomass as the dry cell weight and a poly(3-hydroxybutyrate) (PHB) production of 47.1%. Raw vinasse proportions of 25, 50, and 75% in the culture medium resulted in total inhibition. Vinasse treated at the same ratios led to biomass production in the range 1.7–4.44 g/L. The higher PHB production scenario was obtained in a medium containing dextrose and treated vinasse (7.5%), yielding 5.9 g/L of biomass and 51% of PHB accumulation. The produced PHB was characterized by XRD and FTIR for an analysis of crystalline structure and chemical functional groups, respectively. EDS was employed for a semi-quantitative analysis of the chemical composition, and SEM was used to analyze the morphology of the microgranules. The results of DSC and TGA analyses demonstrated the thermal stability of the obtained PHB. Full article
Show Figures

Figure 1

15 pages, 4368 KiB  
Article
Optimizing Photocatalytic Lead Removal from Wastewater Using ZnO/ZrO2: A Response Surface Methodology Approach
by Hiba Abduladheem Shakir, May Ali Alsaffar, Alyaa K. Mageed, Khalid A. Sukkar and Mohamed A. Abdel Ghany
ChemEngineering 2024, 8(4), 72; https://doi.org/10.3390/chemengineering8040072 - 11 Jul 2024
Viewed by 1157
Abstract
One interesting method for environmental remediation is the use of ZnO/ZrO2 composites in the photocatalytic degradation of lead (Pb) in wastewater. Several studies have investigated different types of composites for the removal of heavy metals from wastewater. However, the efficiency of these [...] Read more.
One interesting method for environmental remediation is the use of ZnO/ZrO2 composites in the photocatalytic degradation of lead (Pb) in wastewater. Several studies have investigated different types of composites for the removal of heavy metals from wastewater. However, the efficiency of these composites in removing the heavy metals remains debatable. Hence, this study investigated the potential of using a ZnO/ZrO2 composite for the removal of Pb from wastewater. Response surface methodology (RSM) was utilized in this work to maximize the Pb photocatalytic removal over ZnO/ZrO2 in simulated wastewater. Based on a central composite design (CCD), the experimental design included adjusting critical process parameters such as catalyst dosage, initial Pb concentration, and pH. The ZnO/ZrO2 composite was synthesized using a physical mixing technique, and its physicochemical properties were studied by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infra-red (FTIR), and X-ray diffraction (XRD). Under visible light irradiation, photocatalytic Pb removal tests were carried out in a batch reactor. The findings showed that a ZnO/ZrO2 dose of 100 mg/L, a pH of 10, and an initial Pb content of 15 ppm were the optimal conditions for maximal Pb removal (above 91.2%). The actual Pb removal obtained from the experimental runs was highly correlated with that predicted using the RSM quadratic model. The usefulness of ZnO/ZrO2 composites for photocatalytic Pb removal is demonstrated in this work, which also emphasizes the significance of RSM in process parameter optimization for improved pollutant degradation. The models that have been proposed offer significant perspectives for the development and scalability of effective photocatalytic systems intended to remove heavy metals from wastewater. Full article
(This article belongs to the Special Issue Advanced Chemical Engineering in Nanoparticles)
Show Figures

Figure 1

20 pages, 5608 KiB  
Article
Synthesis and Characterization of Azo-Based Cyclotriphosphazene Compounds: Liquid Crystalline and Dielectric Properties
by Samerah Habil, Zuhair Jamain and Mohamad Zul Hilmey Makmud
ChemEngineering 2024, 8(4), 71; https://doi.org/10.3390/chemengineering8040071 - 11 Jul 2024
Viewed by 1120
Abstract
The study examined the chemical structure of azo-based liquid crystalline compounds that were altered to form a branch of cyclotriphosphazene. Moreover, the research explored the interplay between their mesomorphic and dielectric properties. The structures of the compounds were defined by Fourier transform infrared [...] Read more.
The study examined the chemical structure of azo-based liquid crystalline compounds that were altered to form a branch of cyclotriphosphazene. Moreover, the research explored the interplay between their mesomorphic and dielectric properties. The structures of the compounds were defined by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and CHN elemental analysis. Only intermediates 2ae and cyclotriphosphazene compounds 4de were mesogenic with smectic A (SmA) and smectic C (SmC) phases, respectively. Intermediate 2d and compound 4d were used as representative samples to determine the type of liquid crystal, which was confirmed through X-ray diffraction (XRD). The calculated d/L ratios for both compounds were 1.69 and 0.76, respectively, indicating that d was approximately equal to L (d ≈ L ≈ 1). This finding suggests that the SmA and SmC phases observed under polarized optical microscope (POM) are arranged in a monolayer. For the dielectric study, only compounds 2de and 4de were proceeded and compared for dielectric characteristics testing. The dielectric constants and dielectric loss factors of these four compounds were measured over the frequency range of 100 Hz to 0.1 MHz at room temperature. The dielectric constant trend decreased with the increasing frequency. Meanwhile, the dielectric loss showed two types of trends. The first trend was identical to the dielectric constant trend, in which the dielectric loss decreased as the frequency increased. However, in the second trend, the dielectric loss began to rise with the increase in frequency and then began to fall gradually after reaching a certain peak. Meanwhile, compounds 4d and 4e had low dielectric constants and losses due to the effect of hexasubstituted cyclotriphosphazene that had been attached as a core. Full article
Show Figures

Figure 1

11 pages, 1540 KiB  
Article
Predictive Modeling and Analysis of Cu–Be Alloys: Insights into Material Properties and Performance
by Mihail Kolev
ChemEngineering 2024, 8(4), 70; https://doi.org/10.3390/chemengineering8040070 - 10 Jul 2024
Viewed by 1145
Abstract
Cu–Be alloys are renowned for their exceptional mechanical and electrical properties, making them highly sought after for various industrial applications. This study presents a comprehensive approach to predicting the compositions of various types of Cu–Be alloys, integrating a Random Forest Regressor within a [...] Read more.
Cu–Be alloys are renowned for their exceptional mechanical and electrical properties, making them highly sought after for various industrial applications. This study presents a comprehensive approach to predicting the compositions of various types of Cu–Be alloys, integrating a Random Forest Regressor within a machine learning (ML) framework to analyze an extensive dataset of chemical and thermo-mechanical parameters. The research process incorporated data preprocessing, model training and validation, and robust analysis to discern feature significance. Cluster analysis was also conducted to illuminate the data’s intrinsic groupings and to identify underlying metallurgical patterns. The model’s predictive power was confirmed by high R2 values, indicative of its capability to capture and explain the variance in the dataset for both testing (R2 = 0.99375) and training (R2 = 0.99858). Distinct groupings within the alloy data were uncovered, revealing significant correlations between composition, processing conditions, and alloy properties. The findings underscore the potential of ML techniques in advancing the material design and optimization of Cu–Be alloys, providing valuable insights for the field of material science. Full article
(This article belongs to the Special Issue New Advances in Chemical Engineering)
Show Figures

Figure 1

14 pages, 3601 KiB  
Article
Facile Lignin Extraction and Application as Natural UV Blockers in Cosmetic Formulations
by Nguyen Van Duy, Pavel Y. Tsygankov and Natalia V. Menshutina
ChemEngineering 2024, 8(4), 69; https://doi.org/10.3390/chemengineering8040069 - 4 Jul 2024
Viewed by 1259
Abstract
Natural compounds are becoming increasingly popular in the fields of pharmaceuticals and cosmetics. One such compound is lignin, a plant-derived aromatic polymer that serves as a natural anti-ultraviolet agent. Conventional methods for extracting lignin from plant materials typically involve performing procedures in harsh [...] Read more.
Natural compounds are becoming increasingly popular in the fields of pharmaceuticals and cosmetics. One such compound is lignin, a plant-derived aromatic polymer that serves as a natural anti-ultraviolet agent. Conventional methods for extracting lignin from plant materials typically involve performing procedures in harsh environments, such as dissolving it in highly alkaline solutions or subjecting it to treatment in acidic conditions. In this study, lignin was extracted from coconut husk under milder conditions, using neutral solvents and ultrasonic treatment, which allowed us to obtain lignin with significantly improved properties. The developed method facilitated the creation of light-colored lignin, which was employed as a natural ingredient in sunblock cream. Furthermore, for the sake of comparison, lignin was extracted under more rigorous conditions using the traditional method. The research findings confirm that the light-colored lignin sample exhibits a higher level of UV absorption. Furthermore, light-colored lignin demonstrates a synergistic effect when combined with commercial moisturizing creams and sunscreens, leading to a significant enhancement in their SPF performance against both UVA and direct sunlight exposure. This study highlights the potential value of incorporating lignin as a valuable natural ingredient in sunblock and cosmetic products. Full article
Show Figures

Figure 1

13 pages, 2381 KiB  
Article
Process Optimization and Biotransformation of Ferulic Acid to Vanillin in a Low-Cost Nitrogen Source
by Abiola Ezekiel Taiwo, Tafirenyika Nyamayaro Madzimbamuto and Tunde Victor Ojumu
ChemEngineering 2024, 8(4), 68; https://doi.org/10.3390/chemengineering8040068 - 4 Jul 2024
Cited by 1 | Viewed by 1352
Abstract
Consumers’ growing knowledge of healthy, environmentally friendly flavors and scents drives the demand for vanillin bioproduction. To save costs on nitrogen during the bioproduction of vanillin, this study investigated the feasibility of using corn steep as a substitute. Using the response surface methodology [...] Read more.
Consumers’ growing knowledge of healthy, environmentally friendly flavors and scents drives the demand for vanillin bioproduction. To save costs on nitrogen during the bioproduction of vanillin, this study investigated the feasibility of using corn steep as a substitute. Using the response surface methodology (RSM) model, the synergistic effects of three variables on vanillin yield were evaluated using Box–Behnken design (BBD). When corn steep liquid, ferulic acid concentration, and pH were 7.72 g/L, 2.33 g/L, and 9.34, respectively, the highest vanillin production of 386 mg/L was achieved. The findings indicated that a maximum overall desirability (D) of 1.0 and a significant (p < 0.05) quadratic model with a regression coefficient (R2) of 0.995 can be used to establish ideal circumstances for the bioproduction of vanillin. This study demonstrated the effectiveness of using corn steep liquor as a low-cost nitrogen source in the medium formulation for the extraction and production of vanillin. Full article
Show Figures

Figure 1

21 pages, 6382 KiB  
Article
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
Cited by 1 | Viewed by 1142
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, [...] Read more.
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
Show Figures

Figure 1

41 pages, 7069 KiB  
Review
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 1168
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 [...] Read more.
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
Show Figures

Figure 1

24 pages, 5955 KiB  
Article
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 1510
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 [...] Read more.
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
Show Figures

Figure 1

22 pages, 610 KiB  
Review
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
Cited by 5 | Viewed by 2375
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, [...] Read more.
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)
Show Figures

Figure 1

Previous Issue
Next Issue
Back to TopTop