Linda Suyati
Department Of Chemistry, Faculty Of Science And Mathematics, Diponegoro University, Jl. Prof. H. Soedarto, S.H., Tembalang Semarang 50275, Indonesia

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Effect of Series Circuit on the Lactose Bioelectricity of a Microbial Fuel Cell System using Lactobacillus bulgaricus Hayati, Dini Noor; Nuryanto, Rahmad; Suyati, Linda
JURNAL SAINS DAN MATEMATIKA Volume 23 Issue 3 Year 2015
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

The need for alternative energy, especially electricity at this time is increasing. The decreasing amount of fuel that cannot be updated, encouraging scientists to conduct researches in finding alternative energy sources which are environmentally friendly, one of the alternative energy is the Microbial Fuel Cell (MFC). The research on the effects of a series circuit on the production of lactose bioelectricity microbial fuel cell system using Lactobacillus bulgaricus has been conducted. This study aim was to assess the effect on the production series circuit lactose bioelectricity MFC system using microbes Lactobacillus bulgaricus. Stages of research included a microorganism preparation of Lactobacillus bulgaricus, and measuring the potential difference in a single, series 1 and series 2 circuits in the MFC system. The potential difference on the measurement of a single, series 1 and series 2 on the substrate lactose were 45 mV / 100mL; 57 mV / 100mL; 58 mV / 100mL respectively where the power were 105.75x10-6 mW; 136x10-6 mW; 139.2x10-6 mW. These results suggested that series circuit was able to increase the potential difference and power on the substrate lactose and tofu whey the MFC system according to Ohm’s law. Keywords: Lactose, microbial fuel cell, Lactobacillus bulgaricus, a series circuit
The Bioelectricity of Tofu Whey in Microbial Fuel Cell System with Lactobacillus bulgaricus Inayati, Nor Sri; Aminin, Agustina L. N.; Suyati, Linda
JURNAL SAINS DAN MATEMATIKA Volume 23 Issue 1 Year 2015
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

Tofu whey is a byproduct of the manufacturing process tofu which containing the remains of protein, fat, carbohydrates and water-soluble substances that do not agglomerate. This study aim was to assess the potential of tofu whey as a substrate in the MFC system and to evaluate the effect of agitation speed to the potential difference generated in the MFC system using Lactobacillus bulgaricus. The potential difference in the variation of the substrate was measured against tofu whey, glucose and lactose. The potential difference with agitation speed variation was carried out at speed of 30, 60, 90, 125 and 250 rpm. The highest potential differences in the substrate variation showed relatively similar results, however they were achieved in different times, which the speed was dependent on the complexity of the substrate molecular structure. While the agitation of 90 rpm gave the highest potential difference. These results indicates that tofu whey potential to be used as a MFC substrate.
Studi Pendahuluan Pemanfaatan Whey Tahu sebagai Substrat dan Efek Luas Permukaan Elektroda dalam Sistem Microbial Fuel Cell Sinaga, David Hamonangan; Suyati, Linda; Aminin, Agustina L. N.
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 2 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

Studi ini bertujuan mengkaji potensi whey tahu sebagai substrat menggunakan Saccharomyces cerevisiae dan mempelajari pengaruh luas permukaan elektroda dalam menghasilkan beda potensial pada sistem MFC. Tahapan penelitian meliputi konstruksi reaktor MFC, pengukuran beda potensial pada variasi substrat yaitu membandingkan beda potensial yang dapat dihasilkan oleh substrat whey tahu dengan substrat glukosa, dan pengukuran beda potensial pada variasi luas permukaan elektroda dengan masing-masing luas permukaan elektroda grafit sebesar 13,29 cm2, 26,58 cm2, 39,87 cm2, dan 53,16 cm2. Hasil penelitian menunjukkan bahwa whey tahu memiliki potensi dengan dihasilkannya beda potensial maksimum 11,73 mV/100 ml substrat dalam sistem MFC menggunakan S. cerevisiae. Hasil studi juga menunjukkan bahwa semakin besar luas permukaan elektroda, semakin besar pula beda potensial yang dihasilkan. Hal ini dibuktikan dengan luas elektroda grafit 53,16 cm2 menghasilkan beda potensial 40,67 mV/100 mL substrat whey tahu dan 300 mV/100 mL substrat glukosa.   Kata kunci: Whey tahu, Microbial fuel cell, Saccharomyces cerevisiae, dual-chamber MFC    The preliminary research about the utilization of soy whey as a substrate and the effect of electrode surface area in microbial fuel cell (MFC) system has been conducted. Laboratory-scale experiment of MFC was carried out in order to determine the ability of soy whey to act as substrate using Saccharomyces cerevisiae and the influence of electrode surface area to generate a potential difference in MFC system. The study includes the MFC reactor design, measuring a potential difference at variation of substrate (soy whey and glucose), and evaluate a potential difference at a variation of graphite electrode surface area. The results show that soy whey has an ability to be applied as a substrate in the MFC system using S. cerevisiae with potential difference 11,73 mV/100 ml. The variation of electrode surface area in the MFC system with four graphite electrodes (53.16 cm2) give the best potential difference with 40,67 mV/100 ml of soy whey and 300 mV/100 ml of glucose substrate.   Keywords: Soy whey, Microbial fuel cell, Saccharomyces cerevisiae, dual-chamber MFC
Whey Tahu sebagai Penghasil Biolektrisitas pada Sistem Microbial Fuel Cell dengan Lactobacillus Plantarum Ismawati, Nur; Aminin, Agustina L. N.; Suyati, Linda
JURNAL SAINS DAN MATEMATIKA Volume 23 Issue 2 Year 2015
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

Bioelectricity of soy whey in Microbial Fuel Cell system with Lactobacillus plantarum has been performed. This study aims to determine the capacity of soy whey as a substrate in the MFC system and determine the influence of the speed of agitation against potential difference generated. The potential difference compared to different substrates, namely soy whey, glucose and lactose. Determination of the potential difference in speed variation agitation performed with variations 30, 60, 90, 125 and 250 rpm. The potential difference at the maximum voltage variation of the substrate obtained by soy whey by 33.3 mV / 100 mL at the 15th hour, whereas glucose and lactose reaches the maximum potential difference at the 12th hour with a relatively similar value. Agitation speed that generates the highest potential difference in soy whey substrate was obtained at 90 rpm with maximum potential difference of 63.1 mV / 100mL at the 14th hour.
Pengaruh Konsentrasi Kalium Asetat dan Natrium Asetat terhadap Konduktivitas Elektrolit Padat KMn(2-x)Mgx O2 dan NaMn(2-x)MgxO2 Nuryanto, Rahmad; Suyati, Linda; Harjono, Cipto; Anggrayni, Rahmaniar
JURNAL SAINS DAN MATEMATIKA Volume 21 Issue 2 Year 2013
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

Pembuatan elektrolit padat KMn(2-x)Mgx O2 dan NaMn(2-x)MgxO2 dilakukan dengan metode sol-gel dengan variasi konsentrasi Kalium Asetat dan Natrium Asetat. Kalium Asetat dan Natrium Asetat dengan konsentrasi 0,1 sampai 0,5 masing-masing dicampur dengan larutan Mangan Asetat, Magesium asetat dan asam sitrat. Larutan-larutan tersebut diaduk selama 2 jam, kemudian dievaporasi dengan temperatur  80°C selama 2 jam, selanjutnya dilakukan drying dengan temperatur 175°C dan kalsinasi dengan temperatur 650°C. Hasilnya berupa padatan diuji konduktivitas dan gugusn fungsinya dengan FTIR. Hasil Penelitian menunjukkan bahwa konduktivitas tertinggi dari elektrolit padat KMn(2-x)Mgx O2 dan NaMn(2-x)MgxO2 diperoleh pada konsentrasi Kalium Asetat 0,1 M dan Natrium asetat 0,1 M. Hubungan antarakonsentrasi(c) dengan konduktivitas (k) untuk KMn(2-x)Mgx O2 adalah c = -64,05 +42,3 dan untuk NaMn(2-x)MgxO2 c = -269,45k +222,85.   Keywords: Elektrolit padat, Sol-gel, KMn(2-x)Mgx O2 , NaMn(2-x)MgxO2, konduktivitas
Pembuatan dan Karakterisasi Katalis Nikel/Zeolit pada Pirolisis Tir Batubara Suyati, Linda
Jurnal Kimia Sains dan Aplikasi Vol 8, No 2 (2005): Volume 8 Issue 2 Year 2005
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (366.71 KB) | DOI: 10.14710/jksa.8.2.39-42

Abstract

Telah dilakukan penelitian untuk pirolisis ter batubara menggunakan katalis Ni-Zeolit. Preparasi katalis dengan impregnasi larutan [Ni(NH3)]2+ 0,15M melalui pengeringan, kalsinasi, oksidasi dan reduksi. Karakterisasi keasaman asam katalisdengan metode gravimetri, adsorbsi gas digunakan untuk mengukur luas permukaan, volume pori dan jejari rerata pori. Kandungan nikel diukur dengan AAS. Karakterisasi katalis dianalisis dengan Gas Sorption Analyser. Hasil penelitian menunjukkan imopregnasi nikel-zeolit sebanyak 86,40%, keasaman padadatan meningkat sebesar 30,19%, Luas permukaan dan volume pori masing-masing meningkat sebesar 42,32% dan 41,29%, sedangkan jejari pori menurun sebesar 4,29%. Konstanta BET terbesar pada Ni/Z sebelum direaksikan sebesar 424,55.
Synthesis of Zeolite from Sugarcane Bagasse Ash Using Cetyltrimethylammonium Bromide as Structure Directing Agent Sriatun Sriatun; Taslimah Taslimah; Linda Suyati
Indonesian Journal of Chemistry Vol 18, No 1 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (439.502 KB) | DOI: 10.22146/ijc.22197

Abstract

The purpose of this research is to synthesize zeolite from sugarcane bagasse ash using cetyltrimethylammonium bromide as structure directing agent. This research used cetyltrimethylammonium bromide surfactant to invent the high porosity, surface area, acidity and thermal stability of synthesized zeolite. The Silica was extracted by alkaline fusion using sodium hydroxide solution. The synthesis was conducted by hydrothermal process at 100 °C for 7 days, ageing process for 24 h and calcination at 500 °C for 5 h. The ratio of Si/Al (v/v) was 1, 15 and 25, meanwhile the concentration of cetyltrimethylammonium bromide was 5x10-4 M, 1x10-3 M and 1x10-2 M. The result showed all of product have strong absorbance at 950–1050 cm-1 and 620–690 cm-1, 420–460 cm-1, double ring at 520–570 cm-1, pore opening at 300–370 cm-1. Vibration of –OH as silanol group or water was indicated by broad absorbance at 3400–3450 cm-1. The diffractograms XRD showed that the product had high crystallinity. The composition of product on ratio Si/Al 1 with concentration of cetyltrimethylammonium 10-2 M is sodalite, the ratio Si/Al 15 and 25 are NaP1 and SiO2 quartz and contain 12.23% and 12.19% of Si, 4.17% and 13.18% of Al, respectively. Observation on SEM revealed that the crystal produced using cetyltrimethylammonium bromide were homogenous and regular in shape.
Degradation of Methylene Blue Using Cadmium Sulfide Photoanode in Photofuel Cell System with Variation of Electrolytes Gunawan Gunawan; Abdul Haris; Didik Setiyo Widodo; Linda Suyati; Wilman Septina
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.53131

Abstract

Methylene blue degradation carried out using cadmium sulfide (CdS) photoanode in photofuel cell (PFC) had been done. CdS synthesized by chemical bath deposition (CBD) on the FTO substrate was used as anode and platinum as a cathode in photoelectrochemical studies. Characterization of CdS thin film was done using EDX, XRD, SEM, Raman, UV-Vis absorption spectrophotometer as well as photocurrent test of the CdS thin film under illumination using potentiostat with the three-electrode system. The EDX result indicated the presence of CdS with an elemental composition of Cd rich. XRD showed the appearance of CdS crystals in cubic and hexagonal formations. SEM image of CdS gave results in the form of crystals of less than 1 mm. Raman spectrum showed the appearance of CdS peaks. The bandgap of CdS was estimated to be 2.38 eV, and the photocurrent test confirmed that the film had a property of n-type semiconductor. Application of CdS thin film as a photoanode in the PFC system using 100 mg/L methylene blue solution showed degradation up to 48% for 2.5 h using a 4 cm2 photoanode, and the maximum potential of 0.8 V was obtained with a photoanode area of 1 cm2. 
Bismuth Oxide Prepared by Sol-Gel Method: Variation of Physicochemical Characteristics and Photocatalytic Activity Due to Difference in Calcination Temperature Yayuk Astuti; Brigita Maria Listyani; Linda Suyati; Adi Darmawan
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.53144

Abstract

Research on synthesis of bismuth oxide (Bi2O3) using sol-gel method with varying calcination temperatures at 500, 600, and 700 °C has been done. This study aims to determine the effect of calcination temperature on the characteristics of the obtained products which encompasses crystal structure, surface morphology, band-gap energy, and photocatalytic activity for the decolorization of methyl orange dyes through its kinetic study. Bismuth oxide prepared by sol-gel method was undertaken by dissolving Bi(NO3)3·5H2O and citric acid in HNO3. The mixture was stirred then heated at 100 °C. The gel formed was dried in the oven and then calcined at 500, 600, and 700 °C for 5 h. The obtained products were a pale yellow powder, indicating the formation of bismuth oxide. This is confirmed by the existence of Bi–O and Bi–O–Bi functional groups through FTIR analysis. All three products possess the same mixed crystal structures of α-Bi2O3 (monoclinic) and γ-Bi2O3 (body center cubic), but their morphologies and band gap values are different. The higher the calcination temperature, the larger the particle size and the smaller the band gap value. The accumulative differences in characteristics appoint SG700 to have the highest photocatalytic activity compared to SG600 and SG500 as indicated by its percent degradation value and decolorization rate constant.
Lactose Bioelectricity on A Microbial Fuel Cell System Parallel Circuit using Lactobacillus bulgaricus Adi Putra; Rahmad Nuryanto; Linda Suyati
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 4 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

Electrical energy needs in Indonesia is estimated to continue growing by 4.6% per year, and if there is nothing to be done to increase the production of electric energy, this figure will increase threefold by 2030. Microbial Fuel Cells (MFC) is one way to produce alternative electric energy by utilizing organic material as a substrate for bacterial metabolic activity that generate electricity. The aim of this study is to examine lactose bioelectricity in a parallel circuit MFC system using Lactobacillus bulgaricus to generate electrical energy. The principle of this study is bioelectrochemistry which is the chemical energy change into electrical energy involving redox reactions by utilizing microbes. This study used a dual chamber MFC system with salt bridge as a connector and conductor of protons from the cathode compartment to the anode compartment. An anode compartment contained the bacteria Lactobacillus bulgaricus and lactose substrate, while the cathode compartment contained electrolyte solution KMnO4 0.2 M and phosphate buffer solution with pH = 7. This study used a single circuit, parallel circuit 1 with 2 cells, and a parallel circuit 2 with 3 cells which were oriented to enlarge the produced electricity current. Bioelectricity of lactose produced power in a single series, parallel 1 and parallel 2 respectively were 72.58 x10-6 mWatt; 155.77 x10-6 mWatt; 270.28 x10-6 mWatt where the power generated was proportional to the parallel circuit electric current. Hence by the same potential difference, the power magnitude in parallel circuit 1 approached twice to the single circuit and the power magnitude in parallel circuit 2 approached three times to the single circuit