CHEMICA: Jurnal Teknik Kimia

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

Yenny Sitanggang, Krissandarta Tarigan, Fauzatu Arabica Yatasya Hasibuan — Wed, 05 Nov 2025 00:00:00 +0000

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 — Tue, 04 Nov 2025 00:00:00 +0000

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, Febbry Romundza, Harlis Harlis, Mia Aina, Asmiyunda Asmiyunda — Wed, 05 Nov 2025 00:00:00 +0000

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.