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KOVALEN: Jurnal Riset Kimia
Published by Universitas Tadulako
ISSN : -     EISSN : 24775398     DOI : https://doi.org/10.22487/kovalen
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry
KOVALEN: Jurnal Riset Kimia is a peer-reviewed journal of chemistry published by the Tadulako University, Indonesia. This journal concern with publishing the original research articles, review articles, and the current issues related to chemistry. Publishing frequency 3 issues per year, in April, August, and December.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 325 Documents
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Analisis Nutrisi Sereal dari Ampas Kelapa dan Ampas Susu Kedelai: Nutritional Analysis of Cereals from Coconut Pulp and Soy Milk Pulp Sari, Nurfita; Sumarni, Ni Ketut; Bahri, Syaiful; Nurhaeni; Amar, Aini Auliana; Syamsuddin; Jusman
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 2 (2023): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i2.16437

Abstract

Coconut pulp and soy milk pulp flour can be combined to reduce the use of wheat flour in the manufacture of cereals. The high fiber and protein content of coconut and soy milk pulp will improve the quality of cereals. The aim of this study was to obtain the mass ratio of coconut and soy milk pulp flour which produces cereals with high nutritional value. The ratio of coconut and soy milk pulp flour used was 0:100; 25:75; 50:50; 75:25; and 100:0 (w/w). Cereal quality was determined based on the value of carbohydrate, protein, fat, fiber, water, and ash content. The results showed that the protein, fat, water, and ash content met the SNI standard, while the fiber content was still higher than the maximum SNI limit. Statistically, the treatment of the ratio of coconut and soy milk pulp flour had a significant effect on all cereal quality parameters (sig. 0.00 < α (0.05)). The high cereal protein content was found in all levels, namely in the range of 14.29-21.14%, while the fat content was in the range of 17.8-34.41%. The use of a 0:100 ratio produces carbohydrate content that meets SNI, which is more than 60%. The use of a combination of coconut pulp and soy milk pulp for the manufacture of cereals that needs to be developed is 25:75 (w/w), however still needs further modifications to reduce fiber content and increase the carbohydrate content.
Sintesis dan Uji Kinerja Membran Selulosa Termodifikasi Polistirena dari Ampas Tebu dengan Aditif Monosodium Glutamate untuk Menurunkan Nilai BOD dan COD Limbah Cair Tahu: Synthesis and Performance Testing of Modified Cellulose Membrane with Polystyrene Derived from Sugarcane Bagasse and Monosodium Glutamate Additive for Decreasing BOD and COD Values in Tofu Wastewater Sianipar, Alvino Jefferson; Senny Widyaningsih; Suyata
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 2 (2023): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i2.16443

Abstract

Tofu liquid waste, which has high BOD and COD values, can contaminate waters if it is directly disposed of without prior treatment. Therefore, waste treatment is necessary before being released into water. One method for treating this waste is by using a cellulose acetate membrane. In this research, a cellulose acetate membrane was synthesized from sugarcane bagasse fibers using the phase inversion method. The membrane was added 6% MSG as an additive to improve its performance. The membrane was applied to treat tofu waste with BOD and COD parameters. The membrane’s flux values obtained in this study were 33.56 L/(m².hour) for water and 26.85 L/(m².hour) for tofu liquid waste. SEM test result showed that the membrane with a 6% MSG additive had more pores and a denser surface compared to the membrane without the additive. The membrane was capable of decreasing BOD and COD values by 62.5% and 75.3% respectively in liquid tofu waste.
Pengolahan Air Limbah Tahu Menggunakan Metode Elektrokoagulasi dan Adsorpsi Secara Kontinyu: Tofu Wastewater Treatment Using Continuous Electrocoagulation and Adsorption Method Wahyuni, Ninik Lintang Edi; Nurcahyo; Leoanggraini, Unung; Sudarman, Robby; Soeswanto, Bambang; Muhari, Emma Hermawati; Ngatin, Agustinus; Sihombing, Rony Pasonang
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 2 (2023): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i2.16446

Abstract

Tofu wastewater contains a lot of protein therefore it is easily degraded to produce foul odors and harmful gases due to microbes. Protein levels can be reduced through the electrocoagulation method which is equipped with adsorption. The purpose of this study is to reduce the value of turbidity, TSS, and COD in tofu wastewater due to the influence of voltage in the electrocoagulation process which is equipped with an adsorption process. This research was conducted with an electrocoagulation process at a rate of 250L/min with voltage variations of 15, 20, and 24Volt in a 10L tank containing 3 pairs of aluminum (Al) electrodes connected with direct current. The output water from the electrocoagulation process flows into the settling basin and flows into the adsorption tank containing activated carbon adsorbent. Both of these continuous processes were the innovation of this research. Sampling was conducted every 10 minutes for analysis of turbidity, TSS, COD, and pH. The results of the output water analysis from the electrocoagulation process after passing through the precipitation and adsorption processes show that increasing the voltage results in the decrease of turbidity, TSS, and COD values, however, increased efficiency and pH. Thus, a voltage of 24V with a flow rate of 250mL/min resulted in the highest efficiency of the voltage variations (15, 20, and 24V) with a process time of 90 minutes with a turbidity impurity reduction efficiency value of 45.42% with a value of 41.36 NTU from 75.22NTU, TSS 91.42% with a decrease to 1827mg/L from 21288mg/L, and COD 55.56% with a COD value of 9600mg/L from 21600mg/L, and a process output water pH of 4.91, as well as a reduction in aluminum electrode weight of 1.024grams.
Pengujian Antimikroba, Kelembaban, Tingkat Iritasi, dan Tinggi Busa pada Hand Soap Berbasis Minyak Jelantah dan Zaitun: Testing of Antimicrobial, Humidity, Irritation, and Height of Foam for Hand Soap Based of Used Cooking and Olive Oils Mapparessa, Syamsul Bakhri; Sabara, Zakir; Suryanto, Andi; Lisa; Lestari, Tri Isra Wahyu
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 2 (2023): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i2.16449

Abstract

Used cooking oil can disturb health if used continues, and the waste can damage of environment if discarded, therefore prevention is needed through processing (recycling) of used cooking oil to economic products, for example, hand soap. This research was the manufacture of hand soap using the waste of cooking oil, olive oil, and KOH as raw materials. The aim is to determine formulations of raw materials on good hand soap on organoleptic tests, pH, microbial inhibitory zones, humidity and irritation levels, and foam height. The formulations between used cooking oil and olive oil are F1 (125 g and 125 g), F2 (150 g and 100 g), F3 (175 g and 75 g), and F4 (200 g and 50 g). This study begins with the manufacture of hand soap using the experimental method, continued by testing the inhibiting zone of growth of Propionibacterium acne bacteria, moisture content, irritation level, foam height through descriptive tests with analytical observational, organoleptic, and pH. Results are all formulas of hand soap have strong effectiveness in inhibiting microbe growth, distinctive organoleptic, moisturizing, and anti-irritation. The foam height has met with SNI 06-4085-1996, however, the pH value has larger than the pH of SNI 06-4085-1966. The best hand soap preparation is Formula 1 (F1) because it has a pH value that is close to the pH value of SNI.
Pengaruh Temperatur Kalsinasi Terhadap Kapasitas Ion Katalis Asam Heterogen Berbasis Silika dan Aplikasinya pada Sintesis Metil Oleat: The Effect of Calcination Temperature on the Ion Capacity of Heterogeneous Silica-Based Acid Catalysts and Its Application in the Synthesis of Methyl Oleate Suryadi, Joko; Nabila, Nanda; Bayhaqi, Syafa Neiska; Andrijanto, Eko
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 2 (2023): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i2.16457

Abstract

Sulfated silica catalyst is a solid acid catalyst which in its application is used to accelerate esterification reactions. The purpose of this study was to determine the effect of calcination temperature and increasing the amount of catalyst on the effectiveness of silica as a catalyst in the formation of methyl oleate through esterification reactions. The synthesis of sulfuric acid catalyst from rice husk ash went through several stages, including preparation of raw material for rice husk ash, production of silica using the sol-gel method, manufacture of silica-based acid catalysts and characterization of the sulfated silica catalyst. The acid catalyst was prepared using impregnation method with sulfuric acid and calcined at various temperatures of 500, 600, 700 and 800oC. The characterization of the acid catalyst formed includes ionic capacity, catalyst performance in the esterification reaction, and the determination of the bond characteristic functional groups using FTIR. The results of ion capacity analysis showed that the highest acidity value was found in the sulfated silica catalyst calcined at 600oC of 0.372 mmol/gram. Testing the performance of the catalyst in the esterification reaction with a ratio of 4:1 (methanol:oleic acid) obtained an ester conversion of 38.89% using a catalyst of 30% of the amount of oleic acid. Identification results using FTIR show that sulfate ions have chemically interacted with silica at around 1103.28 cm-1
Penentuan Suhu Optimum Pirolisis Serbuk Gergaji Batang Kelapa: Determination of the Optimum Temperature of the Pyrolysis of Coconut Trunk Sawdust Waste Aladin, Andi; Syarif, Takdir; Suryanto, Andi; Magefira, Andi; Ardan
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 2 (2023): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i2.16482

Abstract

Research has been carried out on the utilization of biomass waste of coconut trunk sawdust using the pyrolysis method to produce two products simultaneously, namely charcoal and liquid smoke. In order to obtain charcoal products with optimum calorific value, it is necessary to understand the optimum pyrolysis conditions. One of the optimum conditions, namely pyrolysis temperature, was studied in this research. Pyrolysis was carried out in a simultaneous pyrolysis reactor at a flow rate of argon inert gas into the reactor of 2 liters/minute and a pyrolysis time of 2.5 hours with pyrolysis temperature variations of 350, 400, 450, and 500°C, respectively. The study showed that the optimum temperature of 400oC was obtained which gave a yield of 34% charcoal with a calorific value of 7229 kcal/kg. Compared to the calorific value of the raw material for coconut sawdust which is 4400 kcal/kg, there was an increase in the calorific value of the pyrolysis product by 64%. Based on the optimum temperature condition, liquid smoke as a by-product was also obtained with a yield of 45%. Charcoal can be used as a solid fuel or as a bioadsorbent in the treatment of liquid waste or clarification of liquid food products such as virgin coconut oil (VCO). Grade 3 liquid smoke can be used as a biopesticide, while grade 1 liquid smoke can be used as a food preservative. Given the benefits of the two pyrolysis products, both of the products from the current research have a promising market value.
Validasi Metode Analisis Iodin Secara Spektrofotometri UV-Vis pada Dua Variasi Pelarut: Validation of The Method of Iodin Analysis by Uv-Vis Spectrofotometry with Two Variations of Solution Abdilah, Fauzi; Karina Aulia Rahmawati; Widya Tresna Dewi; Keryanti; Hulupi, Mentik
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 3 (2023): December Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i3.16448

Abstract

In this study, the method of analysis of iodine by UV-Vis spectrophotometry was validated. Two other solvents, ethanol, and cyclohexane were used to validate this approach. The UV-Vis Spectrophotometer method's linearity, detection, and quantization limitations, precision, and accuracy were investigated as variables. The results of the linearity tests indicated that the method was proportionally verified because the r values for the two iodine solutions in ethanol and cyclohexane varied between 0.990 and 0.999, respectively. This suggests that the values were higher than 0.99. The LOD values for the ethanol solvent were 4.441 mg/kg and the LOQ was 14.802 mg/kg, whereas the cyclohexane solvent had an LOD value of 2.660 mg/kg and the LOQ was 8.866 mg/kg. According to the required precision acceptance, the %RSD value of 2%, precision values for both standard iodine solutions with two modifications of solvents demonstrated good results. Recovery percentages of ethanol solvents are 96% and cyclohexane solvents are 86%, respectively, according to accuracy measurements. The combined uncertainty value for this test is 0.109 for the ethanol solvent and 0.019 for the cyclohexane solvent, respectively. This research provides a comprehensive understanding of the validity of the iodine analysis method, establishing a robust foundation for the sustainability and reliability of using UV-Vis spectrophotometer in the analysis
Comparison of Total Flavonoid, Phenolic Levels, and Antioxidant Activity between Robusta and Arabica Coffee Ngibad, Khoirul; Yusmiati, Siti Nur Husnul; Merlina, Diana Mey; Rini, Yenny Puspa; Valenata, Valenata; Jannah, Elok Faiqotul
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 3 (2023): December Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i3.16506

Abstract

Coffee contains a lot of phenolic compounds, especially chlorogenic acid, therefore many studies have examined the potential of coffee as an antioxidant. Antioxidants can inactivate oxidation reactions and prevent the formation of free radicals. This research aimed to determine the total phenolic and flavonoid content of the ethanol extract of robusta coffee (Coffea canephora) and the ethanol extract of arabica coffee (Coffea arabica), as well as determine the % inhibition value of Arabica coffee ethanol extract and Robusta coffee ethanol extract and their combination as antioxidants in vitro. Robusta and Arabica coffee powders were soaked in ethanol solvent, respectively, and the filtrate was concentrated using a rotary evaporator. The extract’s flavonoid and total phenolic content were measured by UV-Vis spectrophotometry. An antioxidant activity test was carried out using the DPPH method. The phenolic content of the ethanol extract of robusta coffee powder and the ethanol extract of arabica coffee powder were 7.98 and 9.16 mg QE/g, respectively. The total flavonoid content of the ethanol extract of robusta coffee powder and the ethanol extract of arabica coffee powder were 11.5 and 14.2 mg GAE/g, respectively. The highest % inhibition values of the ethanol extract of arabica coffee powder and the ethanol extract of robusta coffee and their combination as antioxidants in vitro were 71.1, 85.1, and 86.4%.
Pembuatan dan Karakterisasi Kertas Kemasan Berbasis Ampas Kunyit dan Jahe Merah dengan Variasi Konsentrasi Natrium Hidroksida: Preparation and Characterization of Packaging Paper Based on Turmeric and Red Ginger Pulp with Varying Concentrations of Sodium Hydroxide Jannah, Devia Fataya Miftahul; Febryanti, Chyntia Wahyuni; Alfiah, Diana; Huwaida, Melina Rahma; Marhani, Della Agustia; Riniati, Riniati
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 3 (2023): December Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i3.16537

Abstract

The production of herbal beverages such as ginger, turmeric, and other spices generates waste that is commonly discarded. The cellulose content in red ginger is about 60-80%, and in turmeric, it is 50%. The high cellulose content makes red ginger and turmeric waste suitable for use as raw materials for paper production. The objective of this research is to determine the optimum conditions for making paper based on red ginger and turmeric waste. The pulp formation process was carried out using the Semi-Mechanical Method, which involves the addition of chemical solutions and grinding, on a mixture of turmeric and red ginger waste (60:40) with variations of NaOH concentration at 8%, 10%, and 13% (w/v). The papermaking process began with refining and drying the waste, cooking the pulp, adding water and kaolin filler, and then printing. Characterization included antibacterial testing, tensile strength, and grammage. Based on the pulp characterization results at the optimum NaOH concentration of 8%, the moisture content was 8.89%, cellulose content was 49.28%, and lignin content was 9.28%. These parameters comply with the national standard (SNI) for packaging paper. The paper characterization results showed a tensile index of 2.12 Nm/gram, an antibacterial inhibition zone of 5 mm, and a grammage of 13 g/m2. This research indicates that the NaOH concentration influences the moisture, cellulose, and lignin content. Furthermore, based on the characterization results, paper made from turmeric and ginger waste has the potential to be used as antimicrobial packaging paper.
Karakterisasi Pelet Pupuk Organik Berbahan Eco Enzyme: Characterization Of Organic Fertilizer Pellets Eco enzyme Winaningsih, Ima; Suramta, Suramta; Mala, Yanti
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 3 (2023): December Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i3.16541

Abstract

Eco enzyme has nutrients for liquid organic fertilizer. However, the eco enzyme's N, P, K elements are still below the quality standard. Liquid organic fertilizer is disadvantaged in handling, packaging, use, and transportation compared to pellet form. Nutrient levels can be increased through fish bones and rice bran addition. This research aims to determine the characteristics of the best pellets based on Ministry of Agriculture quality standards No. 261/2019, such as length, diameter, density, water content and N, P, K levels. The eco enzyme, water, fish bones, and rice bran’s formula were: C1 (1: 0: 1: 1), C2 ( ¾: ¼: 1: 1 ), and C3 ( ½: ½: 1: 1). Pellets were made by mixing the ingredients with 5% tapioca solution. The tools used to measure pellet length, diameter, and pH were caliper and pH meter. The water content using the gravimetric method. The N, P, and K levels were tested at BALISTA Lembang, Bandung. All formulations’ pellet length and diameter averaged ±12 mm and 4 mm. Water content of C1, C2, and C3 pellets were 8.63%, 8.97%, and 9.18%, respectively. pH of C1, C2, and C3 pellets were 5.7, 5.8, and 5.9, respectively. Particle density for C1, C2, and C3 were 1.37 g/cm3, 1.44 g/cm3, and 1.46 g/cm3, respectively, while the bulk densities were 0.58 g/cm3, 0.63 g/cm3, and 0.64 g/cm3, respectively. The N, P, K levels in C1, C2, and C3 were 5.2%, 4.79% and 4.3%, respectively. C3 is the best formulation. All pellets meet quality standards.

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