CHEMICA: Jurnal Teknik Kimia

Optimization Process of Oil Palm Biomass-Based Activated Carbon for Palm Oil Mill Effluent Treatment

Yenny Sitanggang — 2025-11-05

The rapid expansion of the palm oil industry has significantly increased the volume of palm oil mill wastewater, creating a growing need for its effective treatment and management. Filtration is one of the unit operations involved in treating Palm Oil Mill Effluent (POME), and activated carbon is a commonly used medium in filtration systems. In this study, activated carbon was synthesized from oil palm biomass, including empty fruit bunch (EFB) and palm kernel shell (PKS). The synthesis involved a series of experiments with varying concentrations of H3PO4 (20–60% w/w), activation temperatures (70–100 C), and activation times (30–60 min). The operating conditions for activation were varied using a 23-factor complete factorial design with one center point (analyzed in the Minitab Program). Performance analysis was conducted by evaluating the ability of activated carbon to reduce pollutant parameters in POME, including biochemical oxygen demand (BOD), chemical oxygen demand (COD), and color. Activated carbon from EFB and PKS was successfully synthesized with larger pores, ranging from 10.91 um to 15.22 um, compared to raw EFB and PKS, which had pore sizes ranging from 1.52 um to 2.11 um. It was also found that activation temperature significantly affected the percentage of COD and BOD removal compared to phosphoric acid concentration and activation time. The optimum adsorbent was a 75% PKS:25% EFB mixture, activated with 20 wt% H3PO4 at 70 C for 30 min, achieving a COD removal of 64.0% along with a maximum BOD of 91.2%.

Recovery of Waste Engine Oil Using Vacuum Distillation: Effect of Solvent Pre-Treatment

Hendriyana — 2025-11-04

The purification process of used engine oil, which involves vacuum distillation preceded by pretreatment using chemical solvents such as acetic acid and sodium hydroxide (NaOH), has been studied to improve the quality and efficiency of base oil recovery. Pretreatment was performed using varying solvent concentrations of 5%, 10%, and 15% (v/v) and incubation times of 24, 48, and 96 hours. The primary objective of pretreatment is to decompose polar contaminants and break down complex compounds, making them easier to separate during the distillation stage. The vacuum distillation process was carried out at a pressure of -70 cmHg and a temperature of 230°C, allowing separation of fractions based on differences in boiling points. Experimental results showed that the average density of the base oil distilled from motor oil was 833 kg/m³ and from car oil was 840 kg/m³, approaching the characteristics of new oil. Optimum conditions were achieved by pretreating with 15% v/v acetic acid for 48 hours, resulting in the highest base oil yield of 45.0%. However, NaOH solvent produced more precise visual results, indicating a better ability to bind polar impurities. Chemical component analysis revealed that the main compounds of the new oil, such as octanoic acid, 1,2,3-propanetriol, and glyceryl tridecanoate, were not present in the distillate because they underwent thermal degradation to alkanes and cyclic compounds. On the other hand, additives such as pentatriacontane, hexacosane, and tetrapentacontane-1,54-dibromo were still detected, proving their thermal stability.

Isolation of Bioactive Compounds from Melastoma Malabathricum (Keduruk) for Antibacterial Activity Against Staphylococcus aureus and Pseudomonas aeruginosa to Promote Wound Healing

Harizon Harizon — 2025-11-05

Melastoma malabathricum (keduruk) is a traditional medicinal plant widely used in Southeast Asia for wound healing. However, studies on its bioactive compounds and antibacterial activity remain limited. This study aimed to isolate and identify antibacterial compounds from M. malabathricum leaves and evaluate their potential for topical wound-healing applications. Fresh leaves were extracted using 70% ethanol via maceration, followed by liquid–liquid partitioning and chromatographic purification. Phytochemical screening confirmed the presence of flavonoids, tannins, saponins, alkaloids, and terpenoids. Among the fractions, the ethyl acetate extract exhibited the strongest antibacterial activity and was subjected to further isolation and characterization using ¹H-NMR, ¹³C-NMR, and HR-TOF-MS, revealing flavonoid derivatives as the major constituents. Antibacterial activity was tested by the disk diffusion method against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853. At 10,000 µg/mL, the ethanol extract produced inhibition zones of 15.6 ± 0.6 mm against S. aureus and 12.1 ± 0.5 mm against P. aeruginosa. The isolated flavonoid compound showed stronger inhibition—19.2 ± 0.6 mm and 16.7 ± 0.5 mm, respectively—comparable to gentamicin (22.8 ± 0.7 mm and 21.5 ± 0.6 mm). The antibacterial effect was more pronounced against Gram-positive bacteria, likely due to structural differences in the cell wall. Overall, M. malabathricum leaves, particularly the ethyl acetate fraction and its flavonoid constituents, demonstrate strong antibacterial potential and could serve as natural candidates for developing topical formulations to support wound healing.

Utilization of Modified Amylum from Oil Palm Trunk for The Production of Edible films as A Substitute for Primary Packaging

Faradila Nur Chairunnisya — 2025-11-17

This research aims to produce edible film from non-productive Oil Palm Trunk (OPT) starch. Starch from OPT contains high amylose, so it is easier to modify. In this study, OPT starch was altered through hydrolysis with an acetate buffer solution at pH 7, followed by a bleaching stage. Meanwhile, the edible film-making process involved mixing OPT starch with various types of plasticizers, including gelatin, glycerol, CMC, and chitosan, before the molding and drying process. The best edible film was obtained from starch modified with an acetate buffer solution (20 mL) and Carboxymethyl Cellulose (CMC) plasticizer, processed at 80 °C with a mixing time of 30 minutes. Edible films with these variations had the highest tensile strength, elongation, and Young's modulus values, respectively, of 29.6342 MPa, 1.1333%, and 4.3092 MPa. The results of the solubility test indicate that the primary packaging product, when applied as an edible film for instant noodle seasoning packaging, can help mitigate environmental pollution problems. It dissolves completely in cold water and immediately dissolves when poured over hot water, along with instant noodles. However, there needs to be improvement in the elongation value so that edible film products can protect the contents of their packaging from external influences, including environmental conditions, perfectly when used. The result of this research is the first finding on the application of acetate buffer-modified OPT starch as a primary packaging material, similar to edible films currently on the market.

Optimization and Statistical Modeling of Ultrasonic Depolymerization of k-Carrageenan Using RSM: Predominant Role of pH, Temperature-Time Interactions, and Mechanistic Insights

Nita Indriyani — 2025-11-21

k-carrageenan is a sulfated polysaccharide from red seaweed widely used in the food and pharmaceutical industries. In its low-molecular-weight form (<20 kDa), it exhibits improved cellular uptake and more potent biological activity, making it highly attractive for biomedical applications. Ultrasonic-assisted depolymerization provides an effective method for reducing molecular weight while preserving functional sulfate groups. This study statistically modeled the effects of temperature, time, and pH on k-carrageenan depolymerization using Response Surface Methodology (RSM) with a Central Composite Design (CCD). Experiments were conducted at temperatures ranging from 40 to 60 C, with sonication times of 16 to 32 minutes, and at pH levels of 3 and 6. Molecular weight was estimated via intrinsic viscosity, and structural changes were analyzed by FTIR spectroscopy. The results showed that pH was the most influential factor, with acidic conditions (pH 3) promoting greater molecular weight reduction than near-neutral conditions (pH 6). Temperature and time also had significant effects, and the RSM model effectively captured both linear and quadratic interactions. ANOVA confirmed the model's reliability, with high coefficients of determination (R^2; = 0.9684 at pH 3 and R^2; = 0.9712 at pH 6). FTIR analysis revealed cleavage of alpha(1->3) and beta(1->4) glycosidic bonds, while sulfate ester groups remained stable. In conclusion, ultrasonic depolymerization coupled with RSM provides a predictive and reliable framework to optimize low-molecular-weight k-carrageenan production for biomedical applications.

Formulation of Calcium Microcapsules from Eggshells Using Maltodextrin and Gelatin as Coating Materials for Health Supplements

Maharani Kusumaningrum — 2025-11-17

Eggshell waste is a primary environmental concern resulting from the high consumption of chicken eggs in Indonesia. In 2023, egg consumption reached 6.69 kg/capita/year, producing an estimated 1.86 million tons of eggshell waste. This study investigates, for the first time, the combination of maltodextrin and gelatin via the thin-layer drying method for microencapsulating calcium extracted from eggshells. Eggshells contain around 98% calcium carbonate (CaCO3) and 28% elemental calcium, highlighting their potential as an alternative, low-cost, and sustainable source of natural calcium supplements. However, calcium extracted from eggshells is highly susceptible to environmental degradation, limiting its direct application. To overcome this, microencapsulation technology is applied to enhance calcium stability, solubility, and bioavailability. In this study, calcium was extracted using the Heat Assisted Extraction (HAE) method with 2N HCl at 90 C for 2 hours, then encapsulated with maltodextrin and gelatin at ratios of 1:0, 0:1, 1:1, 2:3, and 3:2. The extracted calcium concentration reached 9.041 mg/g. The best performance was achieved at a maltodextrin-to-gelatin ratio of 3:2, yielding an encapsulation efficiency of 90.33%, a solubility of 77.11%, and a favourable particle morphology. These findings not only demonstrate the potential of eggshell-derived calcium microencapsulation to reduce waste but also contribute to achieving SDG 3 (Good Health and Well-being) by providing alternative calcium sources and to SDG 12 (Responsible Consumption and Production) through waste valorization and sustainable resource utilization.

Influence of Cellulose Acetate Concentration on The Performance of Biopolymer Membranes for Naphthol Dye Removal from Textile Wastewater

Maryudi — 2025-11-27

Membrane technology has continuously advanced as a promising method for treating industrial wastewater, particularly in the textile sector, which generates large volumes of hazardous and toxic effluents. Textile wastewater typically contains high concentrations of complex organic and inorganic pollutants, with dyes being the most persistent and difficult to remove due to their stable aromatic structures. Compared to conventional treatment processes, membrane-based separation offers notable advantages, including lower energy consumption, a smaller footprint, and the ability to separate dissolved contaminants efficiently. In this study, membranes were fabricated via the phase-inversion technique to evaluate their potential for textile wastewater treatment. The membrane preparation involved varying the cellulose acetate (CA) concentration to 13%, 14%, and 15%, while polyethylene glycol (PEG) at 3% was incorporated as an additive to improve pore formation. Acetone was used as the primary solvent during casting. Comprehensive analyses of membrane characteristics—including water uptake, porosity, pure water flux, and dye rejection—were conducted to determine the relationship between polymer concentration and membrane performance. The findings indicate that the membrane with 13% CA exhibited the highest pure water flux, reaching 87.9483 L/m²·h, suggesting greater permeability due to increased pore formation. Conversely, the membrane prepared with 15% CA demonstrated the highest dye rejection, achieving 30.72% for a 20 ppm naphthol dye solution. These results highlight the inherent trade-off between permeability and selectivity: increasing polymer concentration enhances contaminant rejection but reduces membrane flux. The study provides valuable insights for optimizing membrane formulation for textile wastewater treatment applications.

Electrocoagulation for Treating Petrochemical Wastewater: The Effect of Initial pHs and Voltages

Firman Setiadi — 2025-12-10

Petrochemical wastewater (PW) cannot be discharged directly due to its high chemical oxygen demand (COD), which poses environmental risks. Electrocoagulation (EC) is a promising treatment method capable of reducing COD to meet regulatory standards. This study investigates the influence of initial pH and applied voltage on COD removal during EC treatment of PW. In the first stage, the initial pH was adjusted to 12.25 (control), 9, 7, and 5 at a constant voltage of 10 V. In the second stage, voltages of 5, 10, and 15 V were applied at the previously determined optimum pH. The results showed that an initial pH of 7 produced the highest COD removal (52.96%), outperforming pH 9, 5, and 12.25. The superior performance at neutral pH was attributed to the dominant formation of Fe(OH)2 and Fe(OH)3 coagulants, which effectively destabilize and adsorb organic contaminants. Voltage variation further demonstrated that COD removals of 50.22%, 52.96%, and 55.41% were achieved at 5, 10, and 15 V, respectively, indicating higher removal with increasing voltage. However, increasing voltage also raises operational costs. Economic evaluation revealed that pH 7 and 5 V provided the most cost-effective operation, with the lowest operating cost per CODremoved (38.71 IDR/g CODremoved). Although COD removal at this condition was slightly lower than at higher voltages, the cost savings make it the preferred operating point. These findings highlight key operational parameters for optimizing EC performance and support its sustainable implementation for petrochemical wastewater treatment.

Optimization of Local Microorganism (MOL) from Market Waste as a Bioactivator for Composting Fruit and Vegetable Residue

Erna Astuti — 2025-12-05

Untreated organic waste can negatively impact public health and the environment. In traditional markets, accumulated organic waste leads to pollution, increased disease risk, and reduced market aesthetics. Composting offers a practical solution by converting solid organic waste into beneficial products using local microorganisms (MOL) as bioactivators. This study aims to determine the optimal MOL concentration and composting duration for various types of market waste, and to evaluate pH changes and methane production during composting. The MOL was prepared from 5000 g of cabbage waste, 25 g of salt, 250 g of brown sugar, and 5 L of rice washing water. Research variables included waste type and compost-to-MOL ratios. The compost mixture was placed in 5 L sealed jars connected to water-filled bottles and allowed to decompose anaerobically for 30 days. pH measurements were taken every 3 days, gas production was monitored, and N, P, and K levels were analyzed on days 20, 25, and 30. Results indicate that cabbage-based MOL effectively functions as a composting bioactivator. Compost meeting SNI standards for NPK content was produced from fruit peel waste at a fruit peel-to-MOL ratio of 5:1.5 with a 30-day composting period. The pH profile showed a trend toward neutrality throughout the process. Methane detection revealed that controlled anaerobic aeration plays an essential role in improving composting efficiency while potentially reducing greenhouse gas emissions.

Characteristic Evalution of Parijoto Fruit Jam Using Low Calorie Natural Sweeteners Based on Coconut Sugar and Cassava Sugar

Yayuk Mundriyastutik — 2025-12-06

Parijoto (Medinilla speciosa) is a local Indonesian fruit that remains underutilized due to its sour, astringent taste and its highly perishable nature, making it difficult to distribute and commercialize fresh. One potential way to increase its utilization is to process the fruit into jam. This study aims to evaluate the physicochemical and sensory characteristics of parijoto jam formulated with two natural sweeteners: cassava sugar and coconut sugar. The analyses conducted included determination of water content, ash, protein, fat, carbohydrate, energy value, dietary fiber, total sugar, viscosity, and pH. A sensory evaluation was also conducted using a five-point hedonic scale with 35 untrained panelists to assess appearance, aroma, taste, texture, and overall acceptability. The results demonstrated noticeable differences between the two formulations. Jam made with cassava sugar exhibited higher carbohydrate levels (23.70%), energy content (115.96 kcal/100 g), total sugar (21.76%), and viscosity (26.746 mPas), indicating a sweeter taste and thicker consistency. Meanwhile, jam formulated with coconut sugar contained higher dietary fiber (0.93%), which may offer added nutritional benefits. Despite these differences, neither formulation fully complied with the Indonesian National Standard (SNI 3746:2008), mainly due to excessive water content (72–75%) and insufficient soluble solids. Sensory evaluation revealed that both formulations had comparable consumer acceptability. These findings suggest that both sweeteners are viable for parijoto jam development, provided that further optimization is carried out to improve consistency and meet regulatory standards.

Production Of Activated Carbon From Durian Peel Waste Using KOH Activator

Ayu Pramita — 2025-12-13

Durian, a widely consumed fruit in Indonesia, produces substantial peel waste during the harvest season, contributing to environmental problems due to its strong odor and rapid decay. Notably, durian peel contains approximately 57.42% carbon, making it a promising raw material for activated carbon production. Activated carbon is a porous adsorbent, typically composed of 85–95% carbon, and available in granular, pellet, or powdered form. This study investigates the effect of activator type on the characteristics of activated carbon derived from durian peel waste, aiming to identify the optimal activator. The research was conducted at the Environmental Physics Laboratory of the State Polytechnic of Cilacap, using potassium hydroxide (KOH) as the chemical activator. The activated carbon was evaluated based on moisture content, ash content, and iodine absorption capacity. The results indicated a moisture content of 1.62%, ash content of 6.9%, and iodine absorption of 1186.5 mg/g. These values meet the Indonesian National Standard (SNI 06-3730-1995) for high-quality activated carbon. The findings suggest that the use of alkaline activators such as KOH significantly influences the carbon’s pore structure and overall quality. The produced activated carbon demonstrates potential for various applications, particularly in adsorption processes, owing to its high surface area and favorable physicochemical properties. This study supports the valorization of durian peel waste into valuable environmental remediation materials, contributing to both waste reduction and sustainable resource utilization.