Jurnal Beta Kimia

Kinetics of Ammonia Biodegradation Using EM4 with Palm Sugar as an External Carbon Source

Denanda Clarasati Puteri — 2026-03-26

Biological treatment of ammonia requires sufficient carbon availability to maintain stable microbial activity and sustain optimal degradation rates. This study evaluates the kinetics of ammonia biodegradation using an EM4 microbial consortium supplemented with palm sugar as an external carbon source in aerobic batch reactors. Initial ammonia concentrations of 10, 30, and 50 ppm were evaluated over six days of operation. Monitored parameters included ammonia concentration, pH, and biomass (MLSS), while kinetic evaluation applied a pseudo–first‑order model via the ln(S_t/S₀)–time relationship. The results showed removal efficiencies of 79.0–83.4%, accompanied by MLSS increases from ~2,000 to ~4,600 mg/L with higher initial concentrations. The pH range of 5.8–8.5 remained conducive to microbial activity. The ln(S_t/S₀) curves exhibited strong linearity, confirming the suitability of the pseudo–first‑order model, and the reaction rate constants increased under higher substrate and biomass conditions. These findings indicate that palm sugar is effective as an external carbon source for sustaining process stability and accelerating ammonia removal. The integration of EM4 with a natural carbon source demonstrates potential as an efficient, economical, and readily implementable biological approach for ammonia treatment in wastewater.

Effectiveness of Essential Oils as Natural Bioinsecticides for Aedes aegypti Mosquitoes Causing Dengue Fever (DHF): A Systematic Literature Review

Mifahul ulum — 2026-04-30

Dengue Hemorrhagic Fever (DHF) is one of the endemic diseases in Indonesia caused by the Aedes aegypti mosquito. Excessive use of synthetic insecticides in mosquito control efforts can have negative impacts on the environment and human health. Therefore, more environmentally friendly alternatives are needed, such as natural bioinsecticides from essential oils. This article is a literature review that aims to examine the effectiveness of various essential oils, including those from clove flowers (Syzygium aromaticum), lime (Citrus aurantifolia), betel leaf (Piper betle Linn), lemongrass (Cymbopogon citratus), and young areca nut (Areca catechu) as bioinsecticides against Aedes aegypti mosquitoes. The method used was a Systematic Literature Review (SLR) with a PRISMA approach to literature published between 2010 and 2025. Of the 4,916 articles found, five experimental articles were selected for in-depth analysis. The results showed that all essential oils had potential as bioinsecticides, with clove oil showing the highest effectiveness (LC₅₀ value = 3.434%) and young areca nut oil showing the fastest action (LT₅₀ = 56.967 minutes). The content of active compounds such as eugenol, linalool, tannin, and terpenoids in essential oils plays an important role in the mechanism of toxicity and repellency against mosquitoes. Clove oil is the most effective, safe, and environmentally friendly alternative in controlling mosquitoes that cause dengue fever.

Effect of Variations in Acetic Acid Concentration on the Physicochemical Characteristics of Sweet Potato Starch Isolation Results

Marcel Aristha — 2026-04-17

This study aims to analyze the effect of variations in acetic acid concentration (0; 0.5; 1; 1.5; and 2%) on the physicochemical characteristics of starch. The parameters analyzed included moisture content, water absorption, swelling power, and solubility, as well as structural characterization using Fourier Transform Infrared (FTIR). Data analysis was carried out with one-way ANOVA at a significance level of 5%. The results showed that the variation in acetic acid concentration had a significant effect on water content and swelling power (p < 0.05). The value of swelling power increases at certain concentrations and decreases at higher concentrations, indicating a change in the granules. Conversely, water absorption and solubility were not significantly different (p > 0.05). FTIR analysis showed that the addition of acetic acid did not cause covalent chemical modifications, but rather only affected the physical interactions and hydrogen bonds of starch granules.

The Effect of Papain Enzyme Concentration on Protein Content and Antioxidant Activity of Skipjack Tuna (Katsuwonus pelamis) Protein Hydrolysate

Rahel Syallomita Moleong — 2026-04-30

Protein deficiency is one of the most common nutritional problems found in Indonesia. Skipjack tuna is a source of high-quality protein; however, it is highly perishable and therefore requires processing to extend its shelf life. One alternative processing method is the production of protein hydrolysates, which also possess antioxidant activity; nevertheless, optimization of enzyme concentration is required to obtain protein hydrolysates with optimal characteristics. This study aims to analyze the effect of variations in papain enzyme concentration on protein content and antioxidant activity of skipjack tuna protein hydrolysates, where the hydrolysis process was carried out using papain enzyme concentrations of 4%, 5%, and 6% at a temperature of 55°C for 2 hours, and the research data were statistically analyzed using analysis of variance (ANOVA) to determine differences among treatments. Protein content was determined using the Kjeldahl method, while antioxidant activity was analyzed using the DPPH free radical scavenging assay. The results of protein content analysis showed the best value at an enzyme concentration of 6% at 1.22%, and the results of the antioxidant activity test showed the highest value of 66.04% at an enzyme concentration of 6%; in conclusion, an increase in enzyme concentration affects the increase in protein content and antioxidant activity of the hydrolysate, and these findings indicate that optimizing papain enzyme concentration is important in producing skipjack tuna protein hydrolysates with better functional characteristics, thus having the potential to be developed as a functional food ingredient.

Ethyl Lactate as a Green Solvent in Terms of Sustainability and Economic Perspectives in Organic Synthesis Esterification: A Review

Abian Hilmi Hidayat — 2026-05-04

This study presents a comprehensive analysis of ethyl lactate as a sustainable green solvent in organic synthesis, with a focus on feedstock evaluation and economic feasibility. A systematic literature-based approach was employed, covering publications from 2020 to 2025, and assessing two key aspects: (i) the source and cost of feedstocks, including whey, sugarcane molasses, rice straw, and starch, and (ii) the performance of ethyl lactate in various organic transformations. Techno-economic analysis estimates the cost of production (CoP) of ethyl lactate from sugarcane molasses in the range of USD 1,300-1,500/ton, while production from rice straw is estimated at around USD 5,600/ton, highlighting the economic advantage of molasses-based routes. Ethyl lactate has also demonstrated high effectiveness, achieving yields of 90-95% in various reactions such as coupling, metathesis, and ester synthesis. These findings reinforce the potential of ethyl lactate to support the chemical industry's transition toward more environmentally friendly processes, offering a compelling combination of technical performance and economic viability.

Synthesis and Characterization of Carbon Dots (C-Dots) Derived from Tofu Dregs using Solvothermal Method

Siti Nurhalimah — 2026-05-04

Tofu dregs are an agroindustrial organic byproduct generated in large quantities and still contain carbon-rich compounds such as carbohydrates, proteins, and lipids. This carbon content makes tofu dregs a promising alternative precursor for the synthesis of value-added carbon-based materials, one of which is carbon dots (C-Dots). This study aims to synthesize C-Dots derived from tofu dregs using a solvothermal method and to characterize the optical properties, functional groups, morphology, and elemental composition of the resulting material. The synthesis of C-Dots was carried out using a solvothermal process involving heating in a closed system using tofu dregs and 96% ethanol as the solvent. Characterization was performed using UV–Visible (UV–Vis) spectrophotometry, Fourier Transform Infrared–Attenuated Total Reflectance (FTIR–ATR), and Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM–EDX). The UV–Vis analysis revealed an absorption band at approximately 451 nm, which is associated with π→π* electronic transitions in conjugated carbon structures, as well as a shoulder around 524 nm that can be attributed to n→π* transitions originating from lone pair electrons in oxygen-containing functional groups. FTIR analysis indicated the presence of O–H/N–H, C–H, C=C, C–O/C–O–C, and C–N functional groups on the surface of the C-Dots. Meanwhile, SEM analysis showed agglomerated particle morphology, and EDX results confirmed that the main constituent elements of the material are carbon (C), oxygen (O), and nitrogen (N). The results of this study demonstrate that tofu dregs have strong potential to be utilized as a biomass-derived precursor in the solvothermal synthesis of C-Dots.

The Use of Zep Quiz as a Digital Quiz-Based Learning Tool in Teaching Basic Chemical Laws on Student Learning Motivation

Mufliha Nurfajriah — 2026-05-04

The purpose of this study was to determine the relationship between the use of digital learning media Zep Quiz on student learning motivation in the material of Basic Chemical Laws at SMA Ciputat. This study used a quantitative descriptive method. The research sample was 71 grade X students determined by purposive sampling. The instrument used was a questionnaire consisting of 25 question items with two main aspects, namely internal and external motivation using a four-point Likert scale (strongly disagree, disagree, agree, strongly agree). The data obtained by calculating the average percentage and explained descriptively. The results showed that student learning motivation was in the high category, with an average score of 82.65. This indicates that the use of Zep Quiz is related to high student learning motivation.

Integration of Multi-Index Method and Qual2kw Evaluation Modeling of Quality Status and Pollutant Dispersion Pattern of Perian River in Kutai Kartanegara

Dwi Fitria Sari — 2026-05-14

This study is intended to assess water quality and determine the pollution status of the Perian River in its upstream (Perian Village) and downstream (Muara Aloh Village) sections in 2025. (COD) parameters. The findings reveal a marked deterioration in water quality from the upstream to the downstream segment of the river. Based on the CCME- WQI, both locations were categorized as "Poor," with scores of 61.95 (upstream) and 57.20 (downstream). The STORET method classifies the upstream status as "Moderately Polluted" (-23) and the downstream as "Heavily Polluted" (-42). Meanwhile, the PI method assigned a "Lightly Polluted" status to both locations. High concentrations of Nitrate (up to 42.57 mg/L) and Fecal Coliform (up to 12,976 counts/100ml) were the primary contributors to water quality degradation. The total actual COD pollution load was 25,344.52 kg/day, with the upstream area contributing a dominant share of 70.09%. Stringent conservation efforts and waste management along the river are required to prevent further degradation. This study also applied pollutant dispersion modeling using the Qual2Kw method.