Rahmad Nuryanto
Chemistry Department, Faculty Of Sciences And Mathematics, Diponegoro University, 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
Sintesis Dan Karakterisasi Nanopartikel Fotokatalis Tio2 Dengan Doping Tembaga Dan Sulfur Serta Alikasinya Pada Degradasi Senyawa Fenol Haris, Abdul; Widodo, Didik Setiyo; Nuryanto, Rahmad
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 2 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

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Research on synthesis of  copper and sulfur-doped TiO2 with sol-gel method has been done. The study was followed by product characterization with  XRD and  DR UV-Vis spectroscopy. Photocatalist Cu-S TiO2 has been applied in degradation of phenol initiated by energy sources. Cu-S  TiO2 synthesis was performed in one reaction step with TiCl4 as precursor, Cu(NO3)2.3H2O, and H2SO4. Calcination step follows in 450 0C within 4 hours. The method result in nanocrystallin anatase material of Cu-S TiO2 of 8.77 nm in size whose band gap of 1.9 eV decrease from former value of    3.2 eV. By the energy level, photocatalytic proces might be conducted after initiating the material with sun light exposure. Evaluation of the Cu-S TiO2 capability in degrading phenol concentration show that after initiating with  UV, visible, and sun light within 6 hours the treatment result in decreasing of phenol concentration by 84.24%, 83.74% and 66.26%, respectively.   Keywords: Synthesis, characterization, TiO2, Cu-S TiO2, phenolFC     Telah dilakukan sintesis fotokatalis TiO2 dengan doping tembaga dan sulfur dengan metode sol gel dan karakterisasinya menggunakan X-RD dan DR UV-Vis. Fotokatalis­ Cu-S TiO2 terhasil diaplikasikan pada degradasi senyawa fenol menggunakan berbagai energi foton. Sintesisi Cu-S TiO2 dilakukan dalam satu tahap reaksi menggunakan prekrusor TiCl4, Cu(NO3)2.3H2O, H2SO4 dan kalsinasi dilakukan pada suhu 450oC selama 4 jam. Dari hasil sintesis diperoleh partikel nanokristalin anatase Cu-S TiO2 dengan ukuran kristal 8,77 nm, dan menurunkan band gap TiO2 anatase dari 3,2 eV menjadi 1,9 eV sehingga dapat diaplikasikan pada sinar matahari. Dari uji fotokatalisis pada degradasi senyawa fenol  pada sinar UV, sinar tampak dan sinar matahari selama 6 jam, berturut turut diperoleh penurunan konsentrasi fenol sebesar 84,24%, 83,74% dan 66,26%.   Kata kunci : sintesis, karakterisasi, TiO2, Cu-S TiO2, fenol
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
CORROSION RATE OF COPPER AND IRON IN SEAWATER BASED ON RESISTANCE MEASUREMENT W.H. Rahmanto; , Gunawan; Rahmad Nuryanto
JOURNAL OF COASTAL DEVELOPMENT Vol 5, No 2 (2002): Volume 5, Number 2, Year 2002
Publisher : JOURNAL OF COASTAL DEVELOPMENT

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Abstract

Copper and iron metal wire corrosion in artificial sea water have been investigated in three corrosion systems, in the (i) closed bath, (ii) opened or air exposed bath, and (iii) aerated bath. The aim of our investigation is to determine the effect of oxygen contained in the air to the metals’ corrosivity.  Artificial sea water was  prepared by dissolving 173.59 g sodium chloride and 4.91 g potassium chloride in 7.00 kg of water at 230C.The corrosion experiment was carried out under the constant temperature of 32 0C. Decrease of metal masses during corrosion was monitored by measuring the metal resistance change. Our experiment provided the corrosion rate in g.cm-2.s-1 as 4.01 x 10-7 (in closed bath), 4.01 x 10-6 (in opened bath) and 9.43 x 10-6 (in aerated bath) of copper metal, and 2.12 x 10-6 (in closed bath), 5.99 x 10-6 (in opened bath), and 1.07 x 10-5 (in aerated bath) of iron metal. Experimental results show that air oxygen give strong effect on the corrosion of copper and iron metal
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
PRESERVASI CABAI MERAH BESAR (Capsicum annuum L) DALAM SISTEM TERTUTUP BERSUHU 273,40 K BERDASARKAN PERUBAHAN MASSA DAN KADAR VITAMIN C Nurmanita Rusmaningsih; W.H Rahmanto; Linda Suyati; Rahmad Nuryanto
Greensphere: Journal of Environmental Chemistry Vol 1, No 2 (2021): Volume 1 Issue 2 tahun 2021
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (396.701 KB) | DOI: 10.14710/gjec.2021.12987

Abstract

Telah dilakukan penelitian preservasi cabai merah besar (Capsicum annuum L) dalam sistem tertutup bersuhu 273,40 K berdasarkan perubahan massa dan kadar vitamin C. Penelitian bertujuan membuktikan bahwa pada rentang waktu preservasi 4 minggu dalam sistem tertutup (????????????????????????????????????⁄)273,40 K=0 dan (????????????????????????????????????????????????⁄)273,40 K=0. Penelitian dilakukan melalui tiga tahap yaitu preparasi, preservasi cabai merah besar dalam sistem terbuka dan tertutup selama 0 – 4 minggu, dan penentuan massa maupun kadar vitamin C cabai tiap minggunya dengan metode spektrofotometri UV. Hasil menunjukkan bahwa massa cabai pada sistem tertutup konstan yaitu 100 gram, sedangkan pada sistem terbuka terjadi perubahan setiap minggunya yaitu 100 gram, 100 gram, 85 gram, 80 gram, dan 75 gram. Kadar vitamin C cabai merah besar dalam sistem tertutup, tiap minggunya adalah 201,58; 198,58; 193,72; 190,73; dan 190,73 mg L–1. Kadar vitamin C cabai merah besar dalam sistem terbuka tiap minggunya adalah 201,58; 161,91; 129,72; 124,85; dan 80,69 mg L–1. Pada sistem tertutup ????????????????????????=???????????????????? sehingga ????????????????????????????????????⁄=0 dan ????????????????????????????????????=???????????????????? sehingga ????????????????????????????????????????????????⁄=0. Pada sistem terbuka ????????????????????????≠???????????????????? sehingga ????????????????????????????????????⁄≠0 dan ????????????????????????????????????≠???????????????????? sehingga ????????????????????????????????????????????????⁄≠0Kata Kunci: copper (II) oxide, precipitation, photocatalytic activity, irreversible acceptor
Pengambilan Logam Berat Pb dengan Metode Elektrogulasi dalam Sistem Al(s)|Pb(NO3)2(aq), KCl(aq)||H2O(l) Fadilah, Umi; Suyati, Linda; Nuryanto, Rahmad; Widodo, Didik Setiyo; Gunawan, Gunawan
Greensphere: Journal of Environmental Chemistry Vol 3, No 1 (2023): Volume 3 Issue 1 Tahun 2023
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gjec.2023.19363

Abstract

Sumber pencemaran air sebagian besar berasal dari limbah industri. Air limbah tersebut mengandung logam berat yang berbahaya dan beracun seperti logam timbal (Pb). Metode elektrokoagulasi dinilai tepat dan efektif dalam mengurangi polutan logam berat. Proses elektrokoagulasi menghasilkan koagulan yang mampu mengikat logam berat dalam suatu sistem. Tujuan penelitian ini adalah menentukan kondisi optimum (tegangan, konsentrasi KCl, pH dan waktu elektrokoagulasi) dalam pengambilan Pb2+, menentukan kinetika elektrokoagulasi pengambilan Pb dan mengetahui komposisi unsur yang terkandung pada endapan hasil elektrokoagulasi Pb.Pada penelitian ini elektroda Al sebagai anoda dan elektroda C sebagai katoda. Larutan timbal nitrat sebagai limbah artifisial yang mengandung ion timbal dengan elektrolit pendukung KCl. Proses elektrokoagulasi dilakukan pada variasi tegangan 1, 2, 3, 4, dan 5 V, konsentrasi KCl 0,05; 0,10; 0,15; 0,20; 1,00 dan 1,50 M, variasi pH 3, 5, 7, 9 dan 11 serta variasi waktu yang digunakan yaitu 15, 30, 60, 90 dan 120 menit. Analisis konsentrasi Pb2+ setelah elektrokoagulasi dengan menggunakan instrument Spektrofotometer Serapan Atom (SSA). Endapan hasil elektrokoagulasi dikarakterisasi dengan EDX mapping dan FTIR.Hasil penelitian didapatkan kondisi optimum untuk pengambilan Pb2+dalam sistem ini adalah pada tegangan 3 V , konsentrasi KCl 0,10 M , pH larutan 9  dan waktu elektrolisis 120 menit . Kinetika elektrokoagulasi pengambilan Pb mengikuti pseudo orde dua,  dengan k =0,9984 g.mg-1.menit-1, sedangkan unsur yang terkandung pada endapan adalah oksigen, aluminium, timbal, kalium dan klorida. Hal ini menunjukkan bahwa Pb berhasil dikoagulasi oleh Al(OH)3 diperkuat dengan spektra FTIR yang menunjukkan adanya vibrasi Pb-O, Al-O dan O-H.