Orbital: The Electronic Journal of Chemistry

Adsorption of Methylene Blue Using the Biosorbent of Teak Sawdust

Anselmus Boy Baunsele — 2025-11-23

The expansion of the textile industry on a global scale has led to a decline in the quality of our environment due partly to the increasing discharge of untreated textile waste. Industrial textile waste generates two types of environmental pollution-heavy metals and dyes; both possess mutagenic and carcinogenic properties. While efforts have been made to reduce the negative effects of dyes, adsorption remains one of the most cost-effective and effective method. In this context, teak wood sawdust, a readily available byproduct of carpentry activities, was investigated as a potential biosorbent for the removal of methylene blue from aqueous solution. The inherent present of cellulose, hemicellulose, and lignin in teak sawdust make it an ideal biosorbent. The physicochemical properties and surface functionalities of the biosorbent were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX). This study uses the UV-Vis Spectrophotometer measurement method to determine the effect of pH, contact time, and concentration on methylene blue's adsorption capacity. The optimal conditions for the adsorption were identified at pH 6, with an equilibrium time of 30 minutes and an initial methylene blue concentration of 30 ppm. Under these conditions, the adsorption efficiency reached 99.40%. Kinetic modeling revealed that the adsorption process followed a pseudo-second-order model, with a rate constant of 79.70 g mg⁻¹ min⁻¹. The maximum adsorption capacity was determined to be 1.351 mg g⁻¹, and the process achieved a methylene blue removal efficiency of 99.79%, with a Freundlich isotherm constant (n) value of 1, indicating favorable adsorption characteristics.

Green Chemistry Approach to Corrosion Inhibition of Mild Steel in Acidic Medium Using Myrica esculenta Extract

Abhishek sharma — 2025-12-06

Corrosion of mild steel (MS) in acidic environments presents a significant challenge in industrial applications, often leading to structural degradation and economic losses. This study investigated the effectiveness of Myrica esculenta (ME) extract as a green corrosion inhibitor for MS in acidic media. A combination of methods—including weight loss experiments, contact angle measurements, surface analysis, and electrochemical techniques—was employed to evaluate the inhibitor's performance. In the absence of the ME inhibitor, MS experienced rapid corrosion and significant weight loss. However, the addition of ME extract, particularly at a concentration of 40 mg/L, markedly reduced corrosion, achieving an inhibition efficiency of 86.93% after 12 hours. Electrochemical polarization studies revealed a shift in corrosion potential toward more noble values, indicating a reduced tendency for corrosion. Adsorption studies suggested that the inhibitor formed a protective layer through both monolayer and possible multilayer adsorption mechanisms. Contact angle analysis showed an increase in surface hydrophobicity, confirming the formation of a protective interface layer. UV analysis further validated the presence of this layer, which played a crucial role in minimizing pitting and preserving the structural integrity of the mild steel surface. These findings underscore the potential of ME as an effective and environmentally benign corrosion inhibitor.

Artisanal Sunflower Oil: Nutritional Quality, Fatty Acid and Trace Element Profiles, Oxidative Stability, and Non-Carcinogenic Risk Assessment

David Johane Machate — 2025-12-08

This study aimed to produce sunflower oil using an artisanal cold-pressed method and to evaluate its nutritional quality, physicochemical properties, fatty acid composition, mineral profile, and potential non-carcinogenic health risks. The oil contained a high proportion of unsaturated fatty acids, dominated by linoleic (51.92%) and oleic acids (40.45%), and exhibited favorable lipid nutritional indices (AI 0.03; TI 0.13; H/H 29.76). Physicochemical parameters, including low acidity and peroxide values, complied with Codex Alimentarius standards and indicated minimal oxidative degradation. UV-vis spectroscopy revealed characteristic absorption bands to tocopherols, carotenoids, sterols, and unsaturated fatty acids. Oxidative stability (5.03 h) was comparable to values reported for conventional cold-pressed sunflower oils. Four trace elements were detected in decreasing order (Zn > Fe > Al > Mn), all within FAO/WHO and DRI limits, except for slightly elevated Zn for children. Non-carcinogenic risk assessment (HQ and HI < 1) indicated no adverse health risk for consumers aged 8, 18, 30 years. Overall, the artisanal oil demonstrated high nutritional value, acceptable mineral levels, and a favorable safety profile.

Eco-friendly Synthesis and Characterization of Bioactive Iron Oxide Nanoparticles Using Tagetes erecta Leaf Extract for Antioxidant and Anti-Corrosion Application

Shobhit Sharma — 2025-12-16

In this study, we present a sustainable and efficient approach for synthesizing bioactive iron oxide nanoparticles (FeO NPs) using Tagetes erecta leaf extract, an eco-friendly and readily available biological resource. The green synthesis method not only eliminates the need for hazardous chemicals but also leverages the plant’s bioactive compounds, which act as natural reducing and stabilizing agents. The synthesized FeO NPs were meticulously characterized through various advanced techniques, including UV-visible spectroscopy, FTIR, SEM-EDX, XRD, and DLS, confirming their formation, structural attributes, and spherical morphology. The antioxidant potential of FeO NPs was evaluated using DPPH and ABTS assays, revealing significant free radical scavenging activities, particularly in the DPPH assay with a scavenging percentage of 92.91%, comparable to standard antioxidants like ascorbic and gallic acids. Furthermore, the FeO NPs demonstrated exceptional anti-corrosion capabilities, achieving a maximum inhibition efficiency of 79.5% at a concentration of 40 mg, as verified through electrochemical impedance spectroscopy and potentiodynamic polarization methods. This was supported by weight-loss studies, which highlighted superior performance at higher concentrations. By utilizing Tagetes erecta leaves, known for their rich bioactive profile and medicinal properties, this research advances the field of green nanotechnology. It underscores the feasibility of developing multifunctional nanoparticles for applications in environmental protection, biomedicine, and industrial corrosion prevention. This work provides a promising framework for integrating sustainability into nanomaterial synthesis while enhancing their functional properties.

Chemotaxonomic Studies on Some Stereocaulon (Stereocaulaceae, Lichenized Ascomycota) from Southern South America and Antarctica

Aline Siqueira Gianini — 2025-12-18

Lichenized fungi (lichens) produce many compounds especially those derived from the polyketide pathway. These are predominantly phenolic compounds, most of which are unique to lichens, and long-chain fatty acids. These compounds play an important role in the chemotaxonomy of lichens, as they serve as chemical markers for identification at different taxonomic levels. In this work, 100 exsiccates of lichens of the genus Stereocaulon collected in Antarctica, Chile and Argentina were analyzed using thin layer-chromatography, microcrystallization and high-performance liquid chromatography coupled with mass spectrometry. A total of 21 compounds were annotated: rangiformic, norrangiformic, pseudonorrangiformic, vinapraesorediosic B and bourgeanic acids (fatty acids); lobaric, norstictic, menegazziaic, hypoconstictic, colensoic, stictic acids (depsidones); atranorin, gyrophoric acid, -ene''-ene''' glomelliferic acid (depsides); strepsilin (dibenzofuran); lobarin (diphenylether), oxysiphulin (chromone) and four new depsidones: 2''-ene lobaric, 3''-ene lobaric and 4''-ene lobaric and – ene''' lobaric acids. The results of the chemical analysis corroborated the identification obtained through morphological analysis and, in some cases, also allowed the species to be separated into chemical groups. The following species were identified: Stereocaulon corticatulum, S. alpinum (2 chemical groups), S. melanopotamicum, S. implexum, S. tomentosum (4 chemical groups), S. tomentosum var. capitatum (2 chemical groups), and Stereocaulon argus (3 chemical groups).

DFT and Molecular Docking Studies on Antimicrobial Active Synthetic Derivatives of Benzimidazo-quinazoline

Gopala Krishna Murthy H R — 2025-12-18

The development of new antibiotics is crucial due to the growing global threat posed by microbial diseases and the resulting increase in medication resistance. A nitrogen-containing heterocycle with a variety of pharmacological actions, including antibacterial and anticancer effects, is benzimidazole. This study explores the antimicrobial potential of synthesized compounds of Benzimidazo-quinazoline motifs' subjecting them to molecular docking studies against Dihydroorotase from E. Coli and Thymidylate kinase from Staphylococcus aureus. Compounds L2 and L3 showed strong affinities for Dihydroorotase and Thymidylate kinase, respectively, according to molecular docking, which revealed potential interactions. Although more research on other microbial targets is necessary, the study highlights the potential of benzimidazole-quinazoline in blocking bacterial proteins. DFT calculations suggested that L2 and L3 compounds showed the lowest gap energy and were chemically reactive, and promise to serve as potential anti-microbial drug. In general, this study represents a noteworthy advancement towards the creation of potent antimicrobial drugs.

Application of Innovative and Emerging Technologies for the Remediation of POP-Contaminated Sites - A Comprehensive Review

Anna E. Ivbanikaro — 2025-11-24

Persistent organic pollutants (POPs) are toxic chemical substances with a distinctive blend of physic-chemical properties that sustain their persistency for long periods when released into the environment. Many of these compounds were made initially for industrial application, crop production and the control of pests and diseases. Unfortunately, studies have revealed the extremely detrimental effects of the POPs to humans and the environment, due to the poor management of the chemicals. Some of these chemicals are hormone disruptors, linked to diseases like reproductive defects and cancer. A critical assessment of the most current developments in POP remediation technologies for soil is contained in this review. The effective and innovative types of POPs remediation technology were evaluated in this article. Furthermore, innovative and emerging techniques with high remediation performance such as the advanced oxidation processes, nanotechnology, and phytoremediation were thoroughly reviewed. In addition to analyzing the advantages and disadvantages of each technique, this comprehensive review emphasizes the importance of integration strategy in water treatment technologies. The information provided on the emerging, diverse clean-up techniques for remediating POPs contaminated sites would be of great benefit to researchers, policy makers, and environmental professionals facing the challenges of POPs removal from soil.

Molecular Simulations as Tracking Tools for the Dynamics of Reactive Species: A Personal Retrospect

Rodrigo Cordeiro — 2025-12-09

Reactive oxygen and nitrogen species (RONS) govern critical processes in biology and atmospheric chemistry, yet their fleeting dynamics often elude experimental tracking. Quantum chemistry is the go-to method for studying RONS, but fully classical molecular dynamics (MD) simulations, though unconventional for such transient species, offer unique insights into their interactions at complex interfaces. This self-reflective review chronicles a decade of our group’s work developing the GROMOS-RONS force field, harnessing MD’s computational efficiency to explore RONS in lipid bilayers, aquaporin channels, and water-air interfaces. These studies challenge the view of RONS as mere diffusible threats, revealing their selective enrichment and prolonged residence at critical interfacial regions. Simulations uncover nitro-oxidative pathways and transport mechanisms that shed light on unresolved experimental questions. Applications in signaling, therapy, and aerosol chemistry are highlighted, alongside challenges and future directions. By showcasing the GROMOS-RONS model’s strengths for condensed-phase MD, we aim to inspire its broader application as a complementary tool to study RONS dynamics across diverse fields.

Analysis of Students' Misconceptions on Mole Concept Materials and Chemical Formula Using Four-Tier Multiple Choice Diagnostic Test Based Indonesian Curriculum

Heru Christianto — 2025-11-23

This research aims to determine the percentage level of students' misconceptions regarding the concept of moles and chemical formulas as well as each sub-concept where there are misconceptions and their causes in class XI-C SMA Negeri 5 Kupang. Misconceptions were measured using a four-tier diagnostic test instrument based on mixed method research with explanatory sequential design. The research sample was 32 students from class XI-C at SMAN 5 Kupang, who were determined using purposive sampling technique. Data collection techniques were carried out using a four-tier multiple choice diagnostic test, interview guide questionnaire and documentation. Based on the research results, the misconceptions that occur in class XI-C students at SMAN 5 Kupang are classified as moderate misconceptions with a percentage of 41.56%. Significant misconceptions were identified in 5 sub-concepts with an average CR (confidence rating) score above 4.00, namely: (1) Relative Atomic Mass and Relative Molecular Mass 18.75%; (2) Calculation of Mole Concept 24.99%; (3) Reaction Equalization 21.87%; (4) Empirical Formula and Molecular Formula 18.75%; (5) Hydrate Compound 23.43%. Students' misconceptions are caused by 5 factors based on questionnaire and interview data, namely: (1) Students 35.416%; (2) Teachers 6.25%; (3) Learning methods 25.78%; (4) Teaching context 13.125%; (5) Textbooks 20%.

Evaluation of the Quality Parameters of Anti-flu Combinations Containing Phenylephrine Hydrochloride Available in the Brazilian Market

Diana La Luna Bissetti Costa — 2025-11-25

The combination of different active substances in drug products is responsible for optimizing therapies and improving patient adherence. However, the development process of these formulations is highly challenging due to differences in the physicochemical properties of the active ingredients, which can impact formulation stability. Thus, the present study evaluated the incompatibility profile in five different combinations/formulations containing phenylephrine hydrochloride and the maleate compound as a counter-ion by measuring the active pharmaceutical ingredient (API) content and the degradation products (succinyl phenylephrine adducts). This incompatibility occurs due to reactions via Michael addition. The quantification of the API and degradation products was performed using an HPLC-DAD system. The analyses revealed that in all formulations where there is no physical separation between phenylephrine and the maleate counter-ion, a decrease in phenylephrine content and appearance of impurities were observed. Furthermore, the physical separation between the active ingredients was effective, and no markers of the respective reaction were identified. Based on these findings, it is evident that the pharmaceutical form impacts formulation stability, and the reduction in API content along with the increase in impurities may negatively affect product efficacy, quality and safety parameters. This reinforces the need for additional information regarding regulatory registration aspects.