Journal of Green Chemical and Environmental Engineering
Synthesis, In Vitro Antimicrobial Activity, and Molecular Docking Study of Novel Benzylidene Ketamine Analogues as Potential Elongation Factor Tu Inhibitors
The rapid emergence of antimicrobial resistance (AMR) has become a critical global health challenge, leading to prolonged hospitalization, increased healthcare costs, and higher mortality rates. The declining efficacy of conventional antibiotics highlights the urgent need for novel antimicrobial agents with alternative mechanisms of action. This study evaluated the antimicrobial activity of newly synthesized benzylidene ketamine derivatives and explored their potential interactions with bacterial elongation factor Tu (EF-Tu), an essential protein involved in bacterial protein synthesis. Antibacterial and antifungal activities of ketamine and its derivatives (D11-D15) were determined using the broth microdilution method at concentrations ranging from 1 to 512 μg/mL. Ciprofloxacin and fluconazole served as reference antibacterial and antifungal agents, respectively. Molecular docking against EF-Tu (PDB ID: 1DG1) was performed using AutoDock Vina to predict ligand–protein binding affinity. Among the tested compounds, D14 and D15 exhibited the strongest antibacterial activities, with minimum inhibitory concentrations (MICs) of 32 μg/mL against Bacillus subtilis and 64 μg/mL against Staphylococcus aureus, respectively, whereas ketamine showed no detectable antibacterial activity. None of the synthesized compounds inhibited the growth of Candida albicans, while fluconazole displayed an MIC of 1 μg/mL. Docking analysis indicated favorable binding interactions between the active derivatives and the EF-Tu binding site. These findings suggest that benzylidene modification of ketamine enhances antibacterial activity and identifies D14 and D15 as promising lead compounds for the development of EF-Tu-targeted antibacterial agents.
Copyright (c) 2026 Abraham Sisein Eboh, Azibanasamesa D. C. Owaba, Darlington D. Eboh, Okpenkuwo G. Francis, Charis Tiemo, Laura O. Edward (Author) https://creativecommons.org/licenses/by-sa/4.0
Analysis of the Role of Iron (Fe) Content on Nickel Distribution in Limonite and Saprolite Zones Using Energy Dispersive X-Ray Fluorescence (ED-XRF)
Nickel (Ni) is a strategic metal widely used in stainless steel, rechargeable batteries, aerospace, and renewable energy technologies. Increasing demand for electric vehicle batteries has intensified exploration of lateritic nickel deposits, which consist of limonite and saprolite horizons with distinct geochemical characteristics. This study investigates the relationship between iron (Fe) and nickel distribution in lateritic profiles using Energy Dispersive X-Ray Fluorescence (ED-XRF). Samples were collected from PT. Genba Multi Mineral, North Morowali, Indonesia, at depths of 1-6 m. Limonite samples were obtained from 1-3 m, while saprolite samples were collected from 4-6 m. After drying, crushing, and sieving to 200 mesh, the samples were analyzed by ED-XRF. The results reveal an inverse relationship between Fe and Ni contents. The limonite zone contained high Fe (48.76-50.23%) but relatively low Ni (0.70-1.15%), whereas the saprolite zone showed lower Fe (21.01-29.41%) and higher Ni (1.45-2.05%). These trends agree with lateritic nickel enrichment processes, in which Fe is concentrated in limonite while Ni becomes enriched in silicate-rich saprolite during weathering. The findings indicate that Fe content is a useful indicator of nickel distribution in lateritic deposits. In addition, ED-XRF proved to be a rapid, non-destructive, and reliable technique for multi-element analysis of laterite samples. This study provides geochemical information that can support nickel exploration, resource evaluation, and mining optimization in lateritic environments.
Copyright (c) 2026 James William Ariend, Ismail Marzuki (Author) https://creativecommons.org/licenses/by-sa/4.0
The Impact of Occupational Safety and Health (OSH) Programs Hazard Report and Tahan Report on Reducing Workplace Accidents at PT Merdeka Tsingshan Indonesia
This study examines the influence of occupational safety and health (OSH) implementation through Hazard Report and Tahan Report programs on improving workplace safety culture and reducing occupational accidents at PT. Merdeka Tsingshan Indonesia. A quantitative approach was employed using a structured questionnaire distributed to company employees, with responses measured on a Likert scale. The collected data were analyzed using descriptive statistics, validity and reliability testing, and multiple linear regression analysis, including partial (t-test) and simultaneous (F-test) hypothesis testing. The findings indicate that the research instrument is both valid and highly reliable, with a Cronbach’s Alpha value exceeding the acceptable threshold. The coefficient of determination shows that approximately 65.4% of the variation in workplace safety culture can be explained by the independent variables, including employees’ understanding of hazard identification, implementation of reporting programs, compliance and participation levels, and program effectiveness. Furthermore, the results reveal that these variables have a statistically significant effect on safety culture, both individually and collectively. This study concludes that the implementation of Hazard Report and Tahan Report programs plays a crucial role in strengthening safety culture and contributes significantly to the reduction of workplace accidents, highlighting the importance of active employee involvement and consistent safety reporting systems in achieving effective occupational safety management.
Copyright (c) 2025 Ade Putra Niswan Makkasau, Ahmad Padhil, A. Dwi Wahyuni P (Author) https://creativecommons.org/licenses/by-sa/4.0
Method Verification of Carbon and Sulfur Determination in Ferronickel Tapping Samples Using HCS-801 in Accordance with GB/T 20123
Reliable determination of carbon (C) and sulfur (S) in tapping ferronickel is critical for metallurgical quality control and compliance with industrial specifications. Given the complex metallic matrix of ferronickel, verification of analytical performance is essential before routine application. This study verifies the GB/T 20123 standard method for the simultaneous determination of carbon and sulfur in tapping ferronickel using a High Carbon Sulfur (HCS-801) combustion–infrared analyzer. Method performance was assessed using accuracy, precision (repeatability), linearity, limit of detection (LOD), and limit of quantification (LOQ), in accordance with internationally accepted validation principles. Evaluation of recovery testing yielded 97.82 % for carbon and 99.04 % for sulfur, both within acceptable recovery ranges. Precision expressed as %RSD was 1.27% for carbon and 0.70% for sulfur, complying with the Horwitz criterion (% RSD < ½ CV Horwitz) and the general acceptance limit of 2 %. Excellent linearity was obtained across the calibration range, with correlation coefficients (r) of 0.998 for carbon and 0.9984 for sulfur. LOD and LOQ values, calculated based on the standard deviation of response and slope of calibration curves, were 0.0557% and 0.1855% for carbon, and 0.0123 % and 0.0409 % for sulfur, respectively. The results demonstrate that the GB/T 20123 method, when implemented with the HCS-801 analyzer, provides reliable analytical performance for carbon and sulfur determination in tapped ferronickel and is suitable for routine industrial applications.
Copyright (c) 2026 Muh. Azis Albar. J, Muhammad Mattana Anwar, Ardiansah, Mahardika Sandy Ponco, Alexander Malau (Author) https://creativecommons.org/licenses/by-sa/4.0
Optimization of Biodegradable Films from Avocado Seed Starch Using Response Surface Methodology
This study aimed to develop and optimize biodegradable films based on avocado seed starch (Persea americana) using glycerol as a plasticizer and chitosan and carrageenan as fillers. The film formulation was optimized using Response Surface Methodology (RSM) with a Box–Behnken Design to evaluate the effects of formulation variables on biodegradability and mechanical properties. The biodegradability values ranged from 31.93 % to 51.94 %, indicating that all films were biodegradable. Increasing glycerol and carrageenan concentrations significantly increased biodegradability, while higher chitosan concentration improved tensile strength but reduced biodegradability. The optimal formulation was obtained at 2.96 % glycerol, 1.56 % chitosan, and 2.85 % carrageenan, with a predicted biodegradability of 53.11 %. The results indicate a trade-off between mechanical strength and biodegradability, where higher plasticizer content enhances degradation but reduces tensile strength. This study demonstrates that RSM optimization is effective in producing biodegradable films with balanced mechanical and environmental performance, highlighting the potential of avocado seed starch as a sustainable packaging material.
Copyright (c) 2026 Alif Nur Laili Rachmah, Sabrianah Badaruddin, Tamaratritania Citta Trisnantari, Geraldi Rahanra, Ratri Sekaringgalih (Author) https://creativecommons.org/licenses/by-sa/4.0
Determination of Air Pollution Concentrations from Motor Vehicles at Selected Stop-Points Along a Major Highway
Intensified traffic-related air pollution along major highway corridors in developing countries poses increasing risks to environmental quality and public health. This study investigated air pollutant concentrations from motor vehicles at selected stop-points (Locations A - D) along the Benin–Ore–Sagamu highway in southwestern Nigeria. Continuous monitoring was conducted for gaseous pollutants (CO, CO₂, SO₂), particulate matter (PM2.5 and PM10), inorganic ions (SO₄²⁻ and NO₃⁻), and trace metals across four locations during wet and dry seasons. Traffic density was assessed through structured manual vehicle counts at each location, with vehicles categorized by type to assess traffic density and flow patterns. Traffic volume assessment identified Location D as the highest traffic hub, with seasonal variations influencing pollutant levels. Measured levels of CO, SO₂, PM2.5, and PM10 showed significant exceedances of WHO, NAAQS, and FMEnv guidelines, while trace metal analysis indicated extreme enrichment of Rh, Pt, Pd, and other metals, predominantly from vehicular emissions. In contrast, Fe, Zn, and Mn were predominantly derived from natural sources. Sulphate and nitrate exhibited strong dry-season correlations (r = 0.991, p < 0.01) and significant spatial variability, with ANOVA confirming the influence of location on concentrations. Wet-season deposition reduced pollutant concentrations, demonstrating the mitigating role of rainfall. The findings provide a seasonally resolved characterization of traffic-induced air pollution and emphasize the urgent need for regulatory enforcement, fuel quality improvement, and traffic management to protect public health along high-density highway corridors.
Copyright (c) 2026 Wuraola Abake Raji, Lukuman Jimoda, Ayobami Ajani, Adewemimo Popoola, Sunday Adebanjo (Author) https://creativecommons.org/licenses/by-sa/4.0
Polymer Membranes for Energy-Efficient Separation and Clean Energy Applications: Materials Design, Performance Trade-Offs, and Future Perspectives
The low energy requirement, modularity, operational flexibility, and tunable transport properties of polymer membranes make them promising technologies for energy-efficient separation and clean energy applications. Compared with conventional thermal separation processes, membrane systems significantly reduce energy consumption and carbon emissions while enabling compact and scalable process integration. Recent advances in polymer chemistry and nanocomposite fabrication have expanded membrane applications in gas separation, desalination, wastewater treatment, solvent recovery, fuel cells, electrolyzers, and electrochemical energy storage systems. This review critically examines the structure–function relationships of membranes in relation to transport phenomena and key performance characteristics, including permeability, selectivity, conductivity, stability, and fouling resistance. Particular attention is given to high-performance materials such as polymers of intrinsic microporosity (PIMs), thermally rearranged polymers, ion-conductive polymers, and mixed-matrix membranes incorporating metal–organic frameworks, covalent organic frameworks, and two-dimensional nanofillers. Recent strategies to overcome the conventional permeability–selectivity trade-off are reviewed together with challenges related to physical aging, plasticization, chemical degradation, and large-scale manufacturability. In addition to material innovation, this review highlights recent developments in advanced fabrication techniques, machine learning-assisted membrane discovery, and sustainable circular manufacturing approaches. Unlike previous reviews focusing on individual applications, this work provides an integrated perspective connecting separation technologies and clean energy systems through common membrane design principles. The development of durable, scalable, and intelligent membrane platforms will be essential for advancing decarbonization, water security, and sustainable industrial production worldwide.
Copyright (c) 2026 Jibrin Muhammad Yelwa, Auwal Jaji Aliyu (Author) https://creativecommons.org/licenses/by-sa/4.0
Technical Assessment and Optimization of Off-Gas Cooling in Nickel Matte Pyrometallurgy Based on Carbon Variation
Exhaust gas emission management is a critical aspect of pyrometallurgical nickel smelting because it directly affects energy efficiency, operational safety, and overall process sustainability. This study investigates the influence of calcine carbon content on exhaust gas formation and determines the required cooling air volume in an industrial electric furnace operating at approximately 150 tons per hour. The research is based on deterministic mass and energy balance modelling developed from actual operational data obtained from a nickel smelting facility. The analysis quantifies the relationship between carbon oxidation reactions and off-gas generation during the smelting process. Results reveal a strong linear correlation between increasing calcine carbon content and exhaust gas volume. At an average carbon content of 1.96 %, the furnace produces 47,241 Nm³/h of exhaust gas. Under these operating conditions, a cooling air injection of 9,292 Nm³/h is required to reduce the gas temperature from 1000 °C to 800 °C in order to maintain safe furnace operation. The findings demonstrate that precise control of calcine carbon content and optimised cooling air design are essential for improving operational safety and efficiency in nickel smelting. The developed model provides a quantitative basis for designing safer and more efficient industrial off-gas control systems.
Esther Muatiara Santallum Ekklesia Tibalia
Copyright (c) 2026 Sabrianah Badaruddin, Alif Nur Laili Rachmah, Muhammad Ikhsan Taipabu, Farida Diyah Hapsari, Esther Muatiara Santallum Ekklesia Tibalia (Author) https://creativecommons.org/licenses/by-sa/4.0
Vertical Distribution of Silica Content Based on Drill Hole Depth in a Nickel Laterite Deposit, Towara Village, North Morowali, Indonesia
This study aims to observe the relationship between SiO₂ content and Ni content with variations in the depth of laterite nickel production in the Towara area. The independent variable was nickel extraction at depths of 1, 5, 10, and 15 meters from four drill holes spaced 100 meters apart. The dependent variable was nickel ore samples. Samples were obtained through drilling activities, followed by wet and dry preparation, including size reduction, drying, grinding to 200 mesh, and pelletization, before being analyzed using XRF according to the JIS M-8109-1996 standard. The results of the study showed a negative relationship between SiO₂ content and Ni content. A depth of 10 meters had the highest Ni content of 1.977 % at a medium SiO₂ content of 33.577 %. A depth of 15 meters showed a very high SiO₂ content (>66%) with a low Ni content (<0.3 %). The Limonite and Saprolite zones dominated the interval with high Ni content, while the Bedrock and Below Laterite Deposit zones were dominated by high SiO₂ and low Ni content. An increase in silica content at a certain depth indicates a decrease in nickel enrichment potential, making silica an important parameter in evaluating nickel prospect zones.
Copyright (c) 2025 Difri Candra A.N, Muhammad Ihsyam (Author) https://creativecommons.org/licenses/by-sa/4.0
Activated Carbon from Sawdust Biomass Via ZnCl₂ and NaOH Activation for Water Biofiltration Applications
The declining availability of fossil energy sources in Indonesia has driven the development of renewable and environmentally friendly alternatives, including the utilization of biomass waste such as teak sawdust (Tectona grandis L.F.). This study aims to produce activated carbon via pyrolysis and chemical activation using ZnCl₂ and NaOH for water filtration applications. Pyrolysis was conducted at 300-400°C with biomass-to-activator ratios of 1:3, 1:5, and 1:7. SEM analysis revealed that chemical activation increased pore number and size; ZnCl₂ produced larger and more complex pore structures, while NaOH resulted in more uniform pores. FTIR spectra showed a reduction in hydroxyl (O–H), carbonyl (C=O), and ether (C–O) groups with increasing temperature, along with the emergence of aromatic (C=C) bands, indicating enhanced carbonization and structural stability. NaOH activation at 380°C yielded the highest iodine adsorption (1124 mg/g), while ZnCl₂ was optimal at 320 °C (980 mg/g). These results demonstrate that teak sawdust-derived activated carbon possesses a microporous structure and functional surface groups suitable for water purification and efficient removal of organic contaminants
Copyright (c) 2025 Syarwan Hamid, Gusnawati, Thahirah Arief, Muh Ilham Angga Mulia, Hijrah Amaliah Azis, Muh Arman (Author) https://creativecommons.org/licenses/by-sa/4.0
Optimization of Halal Bioadsorbent Particle Size from Pyrolysis Products of Coconut Trunk Sawdust for the Purification of Virgin Coconut Oil (VCO)
One of the critical challenges in the virgin coconut oil (VCO) industry is the selection of crude VCO filtration media that must be strictly guaranteed halal, since VCO is widely used as a food ingredient and for medicinal purposes. In this study, coconut trunk sawdust waste was utilized as a raw material and converted into charcoal through a pyrolysis process. The resulting charcoal was then applied as a bioadsorbent for crude VCO filtration. This article reports the effect of bioadsorbent particle size variations, specifically -/20, 20/50, 50/100, 100/140, 140/200, and 200/- mesh, to determine the optimum particle size that provides the highest VCO clarity. The experiments were conducted under constant conditions with a bioadsorbent-to-VCO ratio of 2% (g/mL) and a filtration time of 10 minutes. The optimum particle size was obtained at 50/100 mesh (200 µm), which resulted in maximum VCO clarity with a turbidity value of 1.48 NTU. Based on this optimum particle size, the filtered VCO showed desirable quality parameters, including lauric acid content of 51.96%, total suspended solids of 5.77%, density of 0.95 g/mL, total plate count (TPC) <10 CFU/mL, and moisture content of 0.0235%. These characteristics meet both the Indonesian National Standard (SNI) and international standards of the Asian and Pacific Coconut Community (APCC). Moreover, the resulting VCO exhibited better clarity than commercial VCO filtered using paper or cloth media (1.59 NTU), while also ensuring halal integrity through the use of bioadsorbent derived from pyrolyzed coconut trunk sawdust
Copyright (c) 2025 Andi Aladin, Rismawati Rasyid, Takdir Syarif, Siti Nur Annisa, Nurul Faradillah (Author) https://creativecommons.org/licenses/by-sa/4.0
Adsorption Equilibrium Isotherm Study of Gold Removal Using Regenerated Activated Carbon from Cyanidation Leachate
Regenerated activated carbon is a type of activated carbon that is reused in adsorption processes after undergoing elution and regeneration. This study evaluates the adsorption performance of regenerated activated carbon compared to fresh activated carbon based on the Freundlich isotherm constant and adsorption heterogeneity. Adsorption experiments were carried out on gold-bearing cyanidation leach solutions with an initial gold concentration of 0.804 mg/L using various activated carbon dosages of 0.25 g/L, 0.50 g/L, 1.0 g/L, 2.0 g/L, 4.0 g/L, and 8.0 g/L. All other parameters affecting absorptivity were kept constant for each dosage, including an adsorbate volume of 0.5 L, free cyanide concentration of 200 mg/L, agitation speed of 150 rpm, contact time of 5 hours, ambient temperature, pH of 10.5, and activated carbon particle size between 1.18-2.36 mm. The results indicate that the Freundlich adsorption constant (Kf) of regenerated activated carbon was 1370 (log Kf = 3.1368), closely comparable to that of fresh activated carbon, which was 1632 (log Kf = 3.2127). The adsorption heterogeneity index (1/n) for regenerated activated carbon was 0.47, also like that of fresh activated carbon (0.46). The optimum dosage of regenerated activated carbon was found to be 4 g/L, yielding a gold adsorption efficiency of 98.7% with a relative activity of 100% compared to fresh carbon, and resulting in a low residual gold concentration of 0.011 mg/L
Copyright (c) 2025 Abdul Rahim Liwang (Author) https://creativecommons.org/licenses/by-sa/4.0
Nanostructured Sodium Molybdate Anodes for Enhanced Bioelectricity Generation and sustainable Wastewater Treatment in Microbial Fuel Cells
Abattoir wastewater (ABW) is characterized by extremely high organic loads, posing serious environmental and management challenges. Conventional treatment methods are often inadequate, highlighting the urgent need for advanced, sustainable technologies. Microbial fuel cells (MFCs) offer a promising dual solution by integrating wastewater treatment with renewable bioelectricity generation; however, their performance is limited by inefficient anode materials. To address this gap, this study investigates sodium molybdate dihydrate (Na2MoO₄·2H₂O) nanoparticles as a novel catalyst for anode modification in MFCs treating ABW. The nanoparticles were synthesized using sodium borohydride as a reducing agent and characterized by UV-Vis spectra, FT-IR (functional groups), XRD (size and crystal structure) and TEM (morphology), revealing non-uniform particles within 20–100 nm. MFCs performances were evaluated by comparing Na2MoO₄ coated (doped) electrodes with unmodified graphite electrodes. Results demonstrated a significant enhancement, with the nano-coated electrode achieving a maximum voltage of 899 mV, power density of 1896 mW/m², current density of 2246 mA/m² at 3500 Ω, and 69.9% COD removal efficiency. These findings confirm that Na2MoO₄ based nanostructured anodes can substantially improve both energy recovery and pollutant removal in MFCs, offering a sustainable approach for treating high-strength industrial effluents such as ABW
Copyright (c) 2025 Akinwumi Odunayo Deborah, Agarry Samuel Enahoro, Aremu Mujidat Omolara, Olowonyo Idayat Adebukola, Sole-Adeoye Opeoluwa Damilola, Fajobi Omoteniola Theresa, Oloyede Victoria Itunu, Abioye Oyindamola Oluwapelumi, Odunola Olufolake, Popoola Adewemimo Oluwakunmi (Author) https://creativecommons.org/licenses/by-sa/4.0
Reinforcement Learning for Intelligent Engineering Systems: A Comprehensive Review of Applications, Challenges and Future Prospects
Reinforcement Learning (RL) is revolutionizing the field of engineering through the solution of challenging, nonlinear, and high-dimensional problems. This review examines how RL enriches the subjects of engineering, such as optimization of industrial processes. Current techniques in optimization and control are inefficient for some complex systems, but RL serves as a better alternative through real-time optimization, product quality improvement, and optimization of process efficiency. The article focuses on recent advancements, challenges, and future prospects for extended integration of RL in engineering and its possibility to revolutionize the field. It also states its limitations and suggestions for future research. The review serves as a good source of information for researchers and engineers determined to remain up to date with recent advancements in RL for intelligent engineering systems and extend its development.
Copyright (c) 2025 Samuel Boluwatife Giwa, Aminah Abolore Sulayman, Kazeem Kolapo Salam, Dauda Olurotimi Araromi (Author) https://creativecommons.org/licenses/by-sa/4.0
Sustainable Conversion of Palm Kernel Shells into Activated Carbon for the Removal of Cu²⁺ and Zn²⁺ from Industrial Paint Wastewater
Industrial paint effluents are major contributors to aquatic heavy metal contamination, creating serious environmental and public health concerns. Conventional treatment methods are often costly and unsustainable, underscoring the need for renewable and effective alternatives. In this study, palm kernel shells (PKS), an abundant agricultural byproduct, were valorized into activated carbon (PKS-AC) for the removal of Cu²⁺ and Zn²⁺ ions from real paint effluent. The adsorbent was prepared through chemical activation and high-temperature carbonization, yielding a material with high fixed carbon content (69.2%) and reduced volatile matter (14.0%), which provided structural stability and enhanced adsorption sites. Batch adsorption experiments revealed optimal conditions at pH 7, 90 minutes, 2.0 g/L dosage, and 55 °C, achieving removal efficiencies of 68.75% (Cu²⁺) and 67.50% (Zn²⁺). Kinetic modeling followed the pseudo-second-order model, suggesting chemisorption, while thermodynamic analysis confirmed the process to be spontaneous and endothermic. Importantly, regeneration tests showed PKS-AC retained strong performance over multiple cycles, highlighting its reusability. The novelty of this work lies in demonstrating the efficacy of PKS-derived activated carbon for treating real industrial paint wastewater, rather than synthetic solutions, while providing a complete evaluation of adsorption performance, kinetics, thermodynamics, and reusability. These findings establish PKS-AC as a sustainable, cost-effective, and circular-economy-driven adsorbent for large-scale wastewater treatment.
Copyright (c) 2025 Opeolwa Damilola Sole-Adeoye, Idayat Adebukola Olowonyo, Kazeem Kolapo Salam, Oreofe Toyin Adedayo, Odunayo Deborah Akinwumi, Stephen Omoniyi Owolabi. (Author) https://creativecommons.org/licenses/by-sa/4.0
The Effectiveness Of Coagulant Stems And Seeds Of Moringa Oleifera In Improving The Quality Of Well Water
This study investigates the effectiveness of natural coagulants derived from Moringa oleifera specifically seeds, stems, and their mixtures in improving well water quality through a coagulation treatment process. Coagulants were prepared by drying and grinding mature Moringa seeds and stems, then applied to 1000 mL samples of well water stirred at 10 rpm for 20 minutes. The coagulant dosages tested were 0.5 g, 1 g, 1.5 g, 2 g, and 3 g, with combination ratios of 1:1, 1:2, and 2:1 (seed : stem). Water quality parameters measured before and after treatment included turbidity, total suspended solids (TSS), total dissolved solids (TDS), pH, nitrite (NO₂), manganese (Mn), iron (Fe), and biochemical oxygen demand (BOD). Results showed that the Moringa seed coagulant exhibited the highest removal efficiency across most parameters, particularly in reducing turbidity, TSS, Fe, and Mn concentrations. The optimal dose for all coagulants was identified as 0.5 g per 1000 mL, beyond which removal efficiency declined or plateauedlikely due to particle restabilization. Mixtures of seed and stem showed moderate effectiveness but did not outperform seed-only treatments, indicating that the active coagulating agents are more concentrated in the seeds. These findings highlight the potential of Moringa seed powder as a low-cost, sustainable, and efficient natural coagulant for decentralized water purification, particularly in rural or resource-constrained areas where access to chemical coagulants is limited.
Copyright (c) 2025 Rezky Awaliah Rusmah, Lili Adriani (Author) https://creativecommons.org/licenses/by-sa/4.0
Enhanced Removal of Malachite Green Dye from Textile Wastewater using TiO₂ Modified Palm Kernel Shell Activated Carbon: Optimization and Mechanistic Assessment
Malachite Green Dye (MGD), a toxic dye commonly discharged by textile industries, poses environmental and health risks. Simultaneously, the disposal of palm kernel shells (PKS), a byproduct of palm oil production, remains an underexploited resource. This study explores the use of activated carbon derived from PKS, modified with titanium dioxide nanoparticles (TiO2-NP), for the adsorption of malachite green dye from aqueous solution. The adsorbent was characterized for its structural and surface chemistry. Batch adsorption experiments were carried out to evaluate the effects of dosage (0.5-2.5 g), contact time (30-150 min), agitation (100-300 rpm), and temperature (30-60 °C). Process optimization was carried out using the Box-Behnken design under the Response Surface Methodology (RSM) framework. Additionally, kinetic and thermodynamic analyses were performed to gain insights into the adsorption mechanism. Numerical optimization revealed a maximum dye removal of 92.6%. Kinetic analysis supported pseudo-second-order behavior, indicating chemisorption, while thermodynamic data confirmed a spontaneous and endothermic process. The adsorbent showed effective regeneration over five cycles, maintaining high efficiency. The prepared adsorbent exhibited a fixed carbon content of 69.50%, while the presence of functional groups involved in dye binding was confirmed through FTIR analysis. These results underscore the potential of PKSAC-TiO₂ as a cost-effective and sustainable adsorbent for dye-laden wastewater treatment.
Copyright (c) 2025 Olowonyo A. Idayat, Sole-Adeoye D Opeoluwa, Kazeem K. Salam , Aremu O. Mujidat, Oreofe A. Toyin, Akinwumi D. Odunayo, Owolabi O. Stephen (Author) https://creativecommons.org/licenses/by-sa/4.0
The Effect of Impurities on Nickel Content In Ore Samples Using Oven and Roasted Preparation Methods
This research was conducted using two sample drying methods: the oven method and the roasting method. Elemental analysis was carried out using the X-Ray Fluorescence (XRF) Epsilon 4 instrument. The study investigated the influence of impurity metals on nickel (Ni) content, particularly the presence of silica (SiO₂) and magnesium oxide (MgO). The results showed that silica (SiO₂) plays a significant role in affecting nickel content. The higher the silica content, the lower the detected nickel content. This is supported by negative correlation coefficients of -0.9725 for the oven method and -0.9090 for the roasting method. The coefficients of determination were 94.58% and 82.62%, respectively, indicating a strong relationship between silica and nickel content. In addition, the relationship between MgO and Ni also showed a negative trend. An increase in MgO content was followed by a decrease in Ni content. The correlation coefficients were -0.9678 for the oven method and -0.9651 for the roasting method, with coefficients of determination of 93.66% and 93.13%. These results confirm a very strong influence of MgO on Ni content. A t-test was conducted to determine whether there was a significant difference between the two drying methods in nickel content measurement. The calculated t-value was 0.013, while the critical t-value was 2.18. Since the calculated value is lower, the null hypothesis (H₀) is accepted, indicating no significant difference between the oven and roasting methods
Copyright (c) 2025 Aqilah Az zahirah, A. Eka Nur Afni Oktaviana (Author) https://creativecommons.org/licenses/by-sa/4.0/
Sustainable Research and Technological Development on Bio-Energy
This paper discusses a comprehensive review of biomass energy sources, environment and sustainable development. This includes the biomass energy technologies, energy efficiency systems, energy conservation scenarios, energy savings and other measures necessary to reduce climate change. Energy use reductions can be achieved by minimising the energy demand, by rational energy use, and by recovering heat. The increased availability of reliable and efficient energy services stimulates the use of more green energies. The adoption of green or sustainable approaches to the way in which society is run is seen as an important strategy in finding a solution to the energy problem. The key factors to reducing and controlling CO2 emissions to the atmospheric sink, which is the major contributor to global warming, are the use of alternative approaches to energy generation and the exploration of how these alternatives are used today and may be used in the future as green energy sources.
Copyright (c) 2025 Abdeen Mustafa Omer (Author) https://creativecommons.org/licenses/by-sa/4.0/
Synthesis and Characterization of Composite Emulsifier from Periwinkle Shell and Gum Arabic applied in Oil-Water Emulsification Process
The Synthetic surfactants employed in the management of oil-polluted water through the emulsification process usually lead to introducing secondary pollutants with more toxic effects on the environment. However, the need to safely mitigate the environmental impact of oil pollution has led to the increasing demand for eco-friendly, bio-based materials for the treatment of oil-polluted water. The effect of Periwinkle Chitosan-Gum Arabic (PSC-GA) composite emulsifier on the stability of oil-water emulsion (10% v/v) was investigated. Chitosan was extracted from the Periwinkle shell through the sequential order of decolorization, demineralization, deproteinization, and deacetylation with 40% NaOH (DCMPA) resulting in a yield of 5.96%. The emulsifier was formed with mixtures of chitosan and gum Arabic at 0%, 1%, and 2% each dissolved in 1%, 2%, and 3% aqueous acetic acid (AA) solution in a randomized experimental design using Box Behnken Design (BBD) under Response Surface Methodology (RSM) of Design Expert (Version 13). An optimum composition of 1.10% PSC, 1.54% GA, and 1.51% AA for the emulsifier with 97.6% stability was obtained from the optimization of the emulsion stability index. This study shows that PSC-GA composite is an effective emulsifier capable of producing stable emulsion with CMC of 0.02 g/l at 0.039 N/m and Zeta potential of over -36 mV which could be applied for the emulsification process in the oil-polluted environment to prevent oil migration.
Copyright (c) 2025 Ismail O. Balogun, Ebenezer O. Dada, Kazeem K. Salam (Author) https://creativecommons.org/licenses/by-sa/4.0
Review of Household Wastewater Treatment with Multistage Filters and Water Hyacinth Bioremediation
Household wastewater in Indonesia is relatively unaffordable by waste treatment technology, as well as the high cost of existing waste technology, so a cheap and easy-to-implement household waste treatment system is needed that can provide optimal results. One sustainable approach that can be applied is a combination of multi-level sieve and bioremediation using water hyacinth (Eichhornia crassipes). This study aims to review the effectiveness of the method in reducing the content of major pollutants, such as total suspended solids (TSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), as well as nitrogen and phosphorus levels in domestic wastewater. Cascade filters function to filter suspended particles and reduce pollutant loads, while water hyacinths play a role in phytoremediation by absorbing excess organic matter and nutrients. Based on various studies that have been carried out, this method has been proven to be able to significantly reduce pollutant levels and improve the quality of treated water. The effectiveness of the system depends on the design of the sieve, the density of hyacinth plants, as well as the environmental conditions in which the system is applied. With relatively low costs and environmentally friendly technology, this method can be an alternative solution for areas that do not yet have an integrated waste treatment system. However, further studies are needed to optimize the design of the system and evaluate the long-term impact on the environment.
Filter Material, Multistage Filter, Water Pollution.
Copyright (c) 2025 Nur Alya Jenar (Author) https://creativecommons.org/licenses/by-sa/4.0
Microalgae as a Feedstock for Carbon Capture Technology
Microalgae have emerged as a promising feedstock for carbon capture technology due to their high carbon sequestration efficiency and potential applications in bioenergy and bioproducts. This study aims to assess the prospects and implementation of microalgae-based carbon capture and storage (CCS) systems in mitigating climate change. The research involves a comprehensive review of microalgae cultivation methods, carbon capture efficiency, and conversion technologies such as biochar production, biofuel synthesis, and direct carbon sequestration in industrial applications. A systematic literature analysis was conducted to evaluate the effectiveness, scalability, and economic feasibility of microalgae-based solutions in mitigating climate change. The study also evaluates key factors influencing the scalability of microalgae-based systems, including biomass productivity, nutrient requirements, and technological advancements in harvesting and processing. Results indicate that microalgae exhibit high CO₂ absorption capacity and can be integrated into existing carbon capture frameworks with minimal land and resource constraints. Additionally, advancements in biorefinery approaches have enhanced the economic feasibility of microalgae-based negative carbon technologies. However, challenges such as high operational costs, energy-intensive processing, and regulatory barriers remain critical factors affecting large-scale adoption. In conclusion, microalgae offer a viable solution for negative carbon technologies, but their successful implementation requires interdisciplinary collaboration, technological improvements, and supportive policies to enhance efficiency and cost-effectiveness
Copyright (c) 2025 Fa'izah Amadia Abdi, Ismi Arnadia Falah (Author) https://creativecommons.org/licenses/by-sa/4.0
Advances in Wind Turbine Technology: Efficiency and Application in Renewable Energy
Electricity is a crucial element in daily life as it supports various human activities. However, many remote areas remain unconnected to the national power grid due to long distances from PLN’s network, resulting in high electricity provision costs. This study employs a qualitative approach by identifying and analyzing literature related to advancements in wind turbine technology, its efficiency, and its application in renewable energy. The review is based on sources from scientific journals, books, research reports, and conference proceedings. Wind energy holds great potential as an environmentally friendly renewable energy solution, particularly in remote areas with low wind speeds, such as Indonesia. Modern wind turbine technology continues to evolve, incorporating aerodynamic design, pitch control systems, and variable speed mechanisms to enhance energy conversion efficiency. Innovations such as the Darrieus turbine, vertical axis wind turbine (VAWT), and the "Antasena" turbine provide effective solutions for low-wind conditions, making them suitable for 3T (Frontier, Outermost, and Disadvantaged) regions. The integration of wind turbines with other renewable energy sources, such as solar panels or micro-hydro systems, along with the use of storage batteries, enhances electricity supply stability in remote areas. Despite challenges such as high investment costs and environmental impacts, proper mitigation strategies can minimize these negative effects. A holistic approach that involves local communities in wind energy projects also contributes to social and economic sustainability.
Copyright (c) 2025 Edi Rahman Hadi, Muhammad Ilham Ramadhan (Author) https://creativecommons.org/licenses/by-sa/4.0
Biodiesel Production from Palm Oil with Heterogeneous Catalysts
Rice production in East Kalimantan Province during 2023 reached around 215,290 tons/year of milled dry grain. Rice is one of the main agricultural products that produce waste in the form of rice husks. Rice husk is stillNot well utilized so that it only becomes a pile of agricultural waste. Rice husk ash contains compounds that can be used as catalyst support, including SiO2. This study aims to determine the effect of rice husk ash catalyst from the KOH impregnation method as a catalyst for making biodiesel from conventional palm oil. Transesterification was conducted on palm oil with the ratio of catalyst mass to oil volume (10%, 15%, 20%). Biodiesel production from palm oil using KOH impregnated catalyst with 2N concentration and 20% catalyst concentration produced the highest yield of 86.3%. Viscosity and density of the results obtained meet the standards.
Copyright (c) 2025 Jonathan, Samuel Gidan Rumpaisum, Rif’an Fathoni (Author) https://creativecommons.org/licenses/by-sa/4.0
The Effect of pH Variations and Aluminum Sulfate Coagulant Dosage on Reducing Turbidity in Salupangkang Tua River Water
This research was carried out using coagulation and flocculation methods. By using a varying pH series, namely 1 – 14 and also varying coagulant doses, namely 10 ppm, 20 ppm, 30 ppm and 40 ppm. The solution whose pH has been adjusted is then stirred using a flocculator with the addition of a coagulant for fast stirring at 100 rpm for 3 minutes, then a flocculant is added for slow stirring at 30 rpm for 3 minutes. After stirring, the turbidity of the solution was measured using a turbidimeter. The research show that pH and coagulant dosage parameters significantly influence the coagulation and flocculation process in water treatment at palm oil mills. The results indicated that the optimal pH for coagulation using aluminum sulfate (Al₂(SO₄)₃) is 7, with an effective coagulant dosage ranging from 30 ppm.
Copyright (c) 2025 Hendra Kurniawan, Nurul Fadillah (Author) https://creativecommons.org/licenses/by-sa/4.0
Economic Potential of the Process of Polyphenol Extraction from Cocoa Pod Husk (Theobroma cacao L.) Using the Ultrasonic-Assisted Extraction Method
Polyphenols are phytochemical substances in plants that can work as antioxidants which can inhibit oxidation and the formation of free radicals. Polyphenols can be found in almost all plants, like cocoa pod husk. This research was conducted to determine the feasibility of the polyphenol extraction process from cocoa pod husk using the ultrasonic-assisted extraction method from an economic perspective based on the effect of drying the material and the type of solvent used. The solvents used were distilled water, 96% ethanol and 95% methanol on materials without drying and materials with drying to a water content of ±11%. From the research results, optimum extraction results were obtained for the samples by drying the material and using distilled water solvent at an extraction time of 60 minutes, which produced a yield of 7.95% and a phenolic content of 22.01% or 220.1248 mg gae/g. From an economic perspective, this process provides a profit of IDR 539,683.05/kg. The extract yield and economic benefits obtained from the ultrasonic-assisted extraction method are greater than from the maceration method
Copyright (c) 2025 Journal of Green Chemical and Environmental Engineering https://creativecommons.org/licenses/by-sa/4.0/
Adsorption of Cadmium Metal in Liquid Waste Using Adsorbent Product of Pyrolysis of Teak Wood Biomass Waste
Liquid waste containing cadmium metal has the potential to be dangerous if not handled properly. One effort to reduce the concentration of cadmium metal in liquid waste is by the adsorption method. Teak sawdust can be processed into charcoal using pyrolysis techniques. Furthermore, charcoal can be activated to be used as a bioadsorbent in liquid waste containing cadmium. The purpose of this study was to determine the mass ratio and optimum contact time of teak sawdust bioadsorbent in reducing the concentration of cadmium metal in liquid waste in the nickel industry. The study was conducted by pyrolyzing teak sawdust waste. The resulting charcoal was then activated. Furthermore, 50 mL of liquid waste containing cadmium was mixed with bioadsorbent and then adsorbed in time variations of 30, 60, 90, 120, 150, 180 minutes with the ratio of active mass to liquid analysis wastewater respectively 0.5g: 50mL, 1g: 50mL, 1.5g: 50mL, 2g: 50mL, and 2.5g: 50mL. After that, the Analysis wastewater was filtered with filter paper and the filtrate was analyzed for cadmium metal content using Atomic Absorption Spectrophotometry (AAS). The results showed that at a mass ratio of bioadsorbent and cadmium liquid waste of 200mg: 50 mL at 150 minutes, the value of the absorbed Cadmium metal content was 0.1845 mg/L or 98.8% of cadmium was absorbed on the bioadsorbent. Bioadsorbent from teak sawdust waste has the potential to be used to reduce the levels of Cadmium metal in liquid waste.