Applied Chemical Engineering

Abstract Batik is a significant textile industry in Indonesia, but it produces liquid waste containing azo dyes that are toxic and can pollute the environment. One approach to mitigate the impact of this waste is through TiO₂ photoelectrocatalysis. This study aims to improve the photoelectrocatalysis performance of TiO₂ by nitrogen doping, in order to achieve more efficient degradation of batik waste. This improvement is reflected in the increased intensity of the anatase phase, the reduction in band gap, and the formation of N-Ti-O bonds. N-doped TiO₂ was synthesized by anodizing titanium plates using urea at molar ratios of 50:50, 95:5, and 90:10, followed by annealing at 500°C for 3 hours. The results showed that the photoelectrocatalysis efficiency for the 90:10 TiO₂:urea ratio reached 90%, significantly higher than undoped TiO₂, which only degraded 50% of the batik waste. The band gap of N-doped TiO₂ was reduced to 2.7 eV, while undoped TiO₂ had a band gap of 3.2 eV. The formation of N-Ti-O bonds was also observed, confirming that nitrogen doping effectively enhances TiO₂'s ability to degrade batik waste through photoelectrocatalysis.

Abstract This study investigates the degradation of Remazol Red RB-133 in batik wastewater using plasma electrolysis, an advanced oxidation process (AOP) that generates highly reactive hydroxyl radicals (●OH). The plasma system, operated at 60 °C with air injection, achieved rapid degradation 86.4% within 5 minutes and up to 99% after 60 minutes exceeding the performance of non-plasma techniques such as electrocoagulation. Degradation kinetics were characterized through UV-Vis spectroscopy and LC-MS/MS, revealing the progressive breakdown of azo chromophores and aromatic rings into low-molecular-weight, less toxic intermediates, which were subsequently mineralized into CO₂ and H₂O, as indicated by significant degradation in Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC). Mass spectral analysis confirmed the formation and subsequent transformation of intermediate compounds, including carboxylic acids and inorganic ions such as SO₄²⁻, NO₃⁻, and NH₄⁺. The degradation mechanism followed a radical-based pathway comprising initiation, propagation, and termination stages. These findings demonstrate the high efficiency and environmental sustainability of plasma electrolysis for treating dye-laden wastewater and provide insights into the mechanistic pathway of azo dye mineralization, contributing to the advancement of water treatment technologies aligned with SDG 6.

Abstract The process of sediment movement significantly affects the development of river structures and regulates reservoir operational functions. The accumulation of extreme sediment items diminishes both reservoir capacity and increases operational challenges for hydroelectric facilities and irrigation systems while causing elevated flood-related dangers. In this present study the authors present a feedback control system based on Artificial Intelligence which predicts river geometry and controls sediment transport. This research analyzes three river areas with actual sedimentation issues i.e. Indus River Basin (Pakistan), Nile River Basin (Egypt), and Tigris-Euphrates System (Iraq/Turkey). An optimized sediment transport control system is developed by the combination of AI-driven modeling, hydrological simulations, GIS-based geospatial analysis and real-time data monitoring according to this research study. Artificial Neural Networks (ANNs), Long Short-Term Memory (LSTM) Networks and Random Forest Regression were used  as AI models. Then pre and post conditions of AI implementation were evaluated in terms of sediment load, sediment control, water saving, etc. Deep learning model LSTM delivers the most successful results for sediment predictions through its R² score reaching 0.94. - Optimized AI-based flushing schedules decreased reservoir sedimentation rates on average by 17.7 percent. AI-based flushing schedules cut water consumption by 18.3% on average which enhances water preservation initiatives.

Abstract Sand filtration stands as a time-tested method for water treatment, yet advancements in technology continue to enhance its effectiveness and efficiency. This paper explores the latest innovations and applications aimed at improving sand filtration for the provision of safe drinking water. Through a comprehensive evaluation of recent developments, this study identifies key innovations in filter media, design modifications, and operational strategies that optimize sand filtration performance. Moreover, it examines the diverse applications of innovative sand filtration techniques in addressing and improving water quality in various contexts. Considering the evaluation of efficiency, scalability, and sustainability of these advancements, this research provides valuable insights into optimizing sand filtration for safe drinking water with focus on rural areas. Finally, through a synthesis of analytical insights and practical case studies, this paper provides a comprehensive overview of the state-of-the-art in sand filtration technology, offering valuable insights for researchers, practitioners, and policymakers seeking to adopt sustainable solutions for the promotion of safe water for rural development.

Abstract The availability of water does not always guarantee its quality, particularly when it is contaminated with iron (Fe), which poses health risks such as kidney failure, cardiovascular diseases, and digestive disorders. This study evaluates the potential of rice straw -modified Ca(OH)₂ (Rs-OCa) as an adsorbent for removing Fe(II) ions from groundwater. Rice straw, a widely available agricultural waste in Indonesia, was chemically modified to enhance its adsorption capacity by increasing active sites, removing lignin, and improving its affinity for metal ions. FTIR analysis confirmed the presence of hydroxyl (-OH) and carboxyl (-COOH) functional groups, while XRD analysis revealed both crystalline and amorphous structures that contribute to stability and adsorption efficiency. Adsorption tests indicated optimal Fe(II) removal at pH 4–5 with an adsorbent dose of 0.75 g per 100 mL of solution. The adsorption isotherm followed the Langmuir model, with a maximum adsorption capacity (Qₘ) of 22.47 mg/g, indicating a homogeneous monolayer adsorption mechanism. The Freundlich model (KF = 8.91 mg/g, n = 2.5) further confirmed surface heterogeneity and high adsorption efficiency at low Fe (II) concentrations.The results demonstrate that Rs-OCa is an effective, economical, and environmentally friendly adsorbent for iron removal from contaminated water.

Abstract This study evaluates the regeneration performance and long-term operability of a continuous-flow, dual fixed-bed ion-exchange system for the simultaneous removal of lead (Pb²⁺) and nitrate (NO₃⁻) from water. Two acrylic columns (total height 45 cm; internal diameter 3.0 cm), each packed with 40 g of resin, were operated in series at pH 7.0 ± 0.1: a strong-acid cation exchanger (Purelite C100) for Pb²⁺ and a strong-base anion exchanger (Resinex™ NR-1) for NO₃⁻. Packed-bed heights were 8.0 cm (≈56.6 mL) for the cation column and 9.0 cm (≈63.6 mL) for the anion column. A 12-run Box–Behnken design investigated inlet concentration (40–80 mg L⁻¹), temperature (25–60 °C), and flow rate (40–100 mL min⁻¹) before and after regeneration with 10% (w/w) NaCl. Under optimized conditions (≈43 °C; 60 mL min⁻¹; 40 mg L⁻¹), Cycle 1 removals were 82.5% (Pb²⁺) and 92.3% (NO₃⁻). After six regeneration cycles, removals declined moderately to 70.2% and 83.6%, respectively, indicating good reusability with a slower efficiency decay for the anion resin. Quadratic response-surface models fit the data well (adjusted R² = 0.973 for Pb²⁺; 0.999 for NO₃⁻); concentration and flow were dominant negative factors, while elevated temperature mitigated mass-transfer limitations. A 10% NaCl protocol is therefore an effective baseline for routine regeneration, with scope for further capacity retention via longer brine contact, occasional deep-clean steps, or tailored regenerant dosing.

Abstract This research focuses on the synthesis of carbon nanoparticles from glucose through the wet chemical method. The dimensions of the generated particles were evaluated through XRD technology, and the capacity of the synthesized nanoparticles to adsorb phenol particles on their surface was illustrated using UV-VIS and FTIR analysis. The calculation of the loading efficiency (DLE) indicated a remarkably high ratio. The dimensions and morphology of the nanoparticles post-adsorption were assessed through Transmission Electron Microscopy (TEM), revealing the presence of tiny particles within the nanoscale range. To assess the cytotoxic effects on pancreatic cancer cells, various medication doses were prepared utilizing the MTT assay. The results indicate that the generated phenol-loaded nanoparticles exhibit significant potential in eradicating cancer cells.

Abstract Water in its natural sources is exposed to many types of pollution, some chemical and some biological. Oil is one of the most common sources of water pollution affecting the coasts, seas, and oceans. Oil pollution of the environment leads to a group of very serious real disasters, some of which can be observed, counted, and controlled from the beginning of the pollution and for several days and months, and among them are not measurable. However, crude oil contains a small soluble fraction referred to as the water-soluble fraction (WSF). Oil pollution and its negative effects on the environment, especially on the aquatic environment and the living organisms that live in it as well as its effects on human health, as well as the causes and sources of oil pollution, and the impact of oil pollution on changing the physical properties of water. In this study different percentages (5, 10, 15, 20 and 25 %) of crude oil were added to tap water, the results showed a marked difference in the physical properties of the water, where an increase in pH, electrical conductivity, and total dissolved solids was observed. Also, methods for treating spilled oil was studied. The results indicate that oil contamination significantly alters water quality parameters, with increased turbidity and reduced surface tension being the most prominent.

Abstract This study presents a numerical investigation of dielectrique barrier discharge (DBD) at atmospheric pressure, focusing on two gas mixture: Ar/He and Ar/O 2 . The objective is to analyse the impact of dielectric permittivity on the plasma behavior in the Ar/He mixture, and the influence of the gas temperature in the Ar/O2 mixture. For the Ar/He case, the relative permittivity of the dielectric is varied from 2 to 12, considering 7 species and 10 chemical reactions. In the Ar/O₂ case, the gas temperature is increased from 350 K to 600 K, with 9 species and 24 chemical reactions taken into account. Key plasma parameters such as species number densities (both neutral and charged), electron temperature, and electron density are evaluated for each scenario. Simulation results for the Ar/He mixture show that increasing dielectric permittivity does not affect the number densities of Ar, He, He⁺, or Hes, but leads to increased densities of electrons, Ars, Ar⁺, and a rise in electron temperature. For the Ar/O₂ mixture, increasing gas temperature causes a reduction in all species densities, while simultaniously increasing the electron temperature.

Abstract The Measurements of temperature relaxation (T 1 ) of methyl groups (CH 3 ) 3 , the tunnel splitting (ut Hz), and energy activation (Eg) of some organic chemistry samples were done in this work. The Measurements were performed at different temperature ranged from 4 – 300 K. It was found that the Eg values for all the compounds ranged from 480-1240 kg/mol and the data was used to measure the magnitude values of the potential energy barriers (V 3 ) of the (CH 3 ) 3  in these compounds. The thermal composition mechanism was also investigated and the results indicate the relationship between the hopping rate and the form and height of the levels hindering barriers of collective motion of methyl group protons in samples. In this research, additional calculation for CH 3  tunneling splitting as a result to tunneling frequency was also performed.

Abstract Background:  Coumarin derivatives have emerged as pivotal compounds in pharmaceutical and biomedical research due to their multifaceted therapeutic potential. Naturally occurring in a wide range of plants, coumarins exhibit diverse biological activities including antimicrobial, anticancer, antioxidant, anti-inflammatory, and anticoagulant effects. Their structural versatility, comprising fused benzene and α-pyrone rings, offers a valuable scaffold for the design of novel pharmacophores targeting complex diseases such as cancer, neurodegenerative disorders, and infectious diseases. Methods:  This review synthesizes recent advancements in the design, synthesis, and therapeutic applications of coumarin derivatives. It explores traditional synthetic routes such as the Pechmann and Perkin condensations alongside modern environmentally friendly techniques including microwave-assisted synthesis and solvent-free reactions. Furthermore, the article examines mechanistic insights into coumarins' bioactivity, involving pathways like apoptosis induction, oxidative stress modulation, and inhibition of molecular targets including carbonic anhydrases, kinases, and efflux pumps. Results: Numerous coumarin derivatives have demonstrated significant in vitro  and in vivo  bioactivity. Antimicrobial derivatives showed broad-spectrum efficacy, including multidrug-resistant pathogens. Anticancer coumarins exhibited cytotoxicity in several human cancer cell lines, with some outperforming standard chemotherapeutics. Derivatives also showed potent antioxidant effects, primarily through radical scavenging and modulation of redox signaling pathways. On the other hand, the synthesis of hybrid coumarin molecules further enhanced biological efficacy and solubility, addressing key pharmacokinetic challenges. Conclusion:  Coumarins represent a versatile and promising class of compounds for future drug development. Ongoing innovation in green chemistry and molecular design is essential to overcome existing limitations such as low aqueous solubility and regulatory restrictions. This review reinforces coumarins' potential as lead structures in pharmaceutical engineering, advocating for continued exploration of their applications across therapeutic domains.