Currently in Indonesia, propellant research is still rarely carried out due to bureaucratic and b... more Currently in Indonesia, propellant research is still rarely carried out due to bureaucratic and budgetary problems. This study aimed to determine the optimum composition of propellant using local sources of nitrate compounds based on its combustion heat value and to study the effect of the composition on its combustion heat value. The propellant composition used in this study consists of oxidizing agents (local nitrate compounds), fuel (Aluminium), binder (polyester-based resin), and additive (catalyst). A bomb calorimetry method (ASTM D5865/5865-19) was used to determine the combustion heat value of the propellant. The results showed that the heat of combustion of local content nitrate compound-based propellants was high (> 1500 cal/g), adding binder to the propellant composition increases the heat of combustion. Ammonium nitrate-based propellant has the highest heat of combustion value of 3,788 cal/g. The optimum binder composition in the propellant was 33% (w/w). Based on this...
Three-layer Aurivillius compound bismuth titanate (Bi4Ti3O12) is well known for having interestin... more Three-layer Aurivillius compound bismuth titanate (Bi4Ti3O12) is well known for having interesting properties such as ferroelectric and photocatalyst. Many researchers reported that the unique plate-like shaped particle affecting ferroelectric and photocatalyst properties. The molten salt synthesis is the common simple method to obtain that unique morphology. In this research, Bi4Ti3O12 was synthesized using single molten salt NaCl at various temperatures, which is 800, 850, 900, and 950 oC. X-Ray Diffraction data showed that all obtained Bi4Ti3O12 have a B2cb space group with no impurities detected. The Raman spectra shows the characteristic vibration modes of Bi4Ti3O12 at 62, 117, 228, 269, 332, 364, 536, 851 cm-1. The plate-like shaped particle was confirmed by SEM analysis. Based on SEM images, the size of the particle increases as the synthesis temperature increased, which is due to the thermal effect on grain growth
The Journal of Pure and Applied Chemistry Research, 2021
Three-layer Aurivillius compound bismuth titanate (Bi4Ti3O12) is well known for having interestin... more Three-layer Aurivillius compound bismuth titanate (Bi4Ti3O12) is well known for having interesting properties such as ferroelectric and photocatalyst. Many researchers reported that the unique plate-like shaped particle affecting ferroelectric and photocatalyst properties. The molten salt synthesis is the common simple method to obtain that unique morphology. In this research, Bi4Ti3O12 was synthesized using single molten salt NaCl at various temperatures, which is 800, 850, 900, and 950 oC. X-Ray Diffraction data showed that all obtained Bi4Ti3O12 have a B2cb space group with no impurities detected. The Raman spectra shows the characteristic vibration modes of Bi4Ti3O12 at 62, 117, 228, 269, 332, 364, 536, 851 cm-1. The plate-like shaped particle was confirmed by SEM analysis. Based on SEM images, the size of the particle increased along with the synthesis temperature, which is due to the thermal effect on grain growth.
CaTiO3 as one of the perovskite-based photocatalysts has a band gap energy of 3.5 eV (~354 nm), t... more CaTiO3 as one of the perovskite-based photocatalysts has a band gap energy of 3.5 eV (~354 nm), thus will work at the ultraviolet light region. One of the strategies to decrease the band gap energy is doping metal. In this research, CaTiO3 was doped by Fe element as purposes to decreasing its band gap energy. Fe doped CaTiO3 compounds were synthesized using molten NaCl salt method. The diffractogram samples showed that the Fe-doped CaTiO3 crystal was successfully prepared. Meanwhile, the SEM images showed that the particle shape was regular polyhedral morphology, and doping Fe3+ caused the particle size to decrease and agglomerated. The UV-Vis DRS spectra showed that the Fe-dopant revealed the absorption light at visible range wavelength.
Reducing a high-operating temperature of solid oxide fuel cell (SOFC) to intermediate temperature... more Reducing a high-operating temperature of solid oxide fuel cell (SOFC) to intermediate temperature SOFC (IT-SOFC, 500-750oC) poses a great challenge in the sense of developing solid electrolyte at intermediate temperature range. In response to this, we report a novel composite La9.33Si6O26 (LSO) Ce0.85Gd0.15O1.925 (CGO) in this study. The synthesis of LSO-CGO composite was carried out by combining LSO with CGO (9:1, 8:2, and 7:3 in weight ratio) using solid state reaction method. In order to get a dense pellet, all of the products were sintered at 1500°C for 3 hours. The X-ray diffraction pattern of sintered pellets show typical patterns for both of LSO and CGO which indicate that the composite was successfully formed. The highest conductivity was detected in 7LSO-3CGO, i.e. 2.10×10-3 S cm-1 at 700oC and also has low activation energy (0.60 eV). This result suggests that the LSO-YSZ composites are good oxide ion conductors and may potentially be used as an alternative solid electroly...
IOP Conference Series: Earth and Environmental Science, 2021
Efforts to replace conventional fluids as coolants for heat transfers with new fluids are continu... more Efforts to replace conventional fluids as coolants for heat transfers with new fluids are continuously being made to improve heat transfer efficiency. Nanofluids are currently widely studied around the world as candidates for conventional fluids substitutes. In this research, the synthesis of Al2O3-ZrO2 nanocomposites for heat transfer nanofluid applications was carried out. The synthesis of the nanoparticles was conducted by the hydrothermal method. Here, we used ZrO2 to improve the characteristics of Al2O3. The results of XRD analysis showed that the nanocomposite had an Al2O3 gamma structure. The Al2O3 nanoparticles and Al2O3-ZrO2 nanocomposite have a crystallite size of 7.41 nm and 6.84 nm, respectively. The addition of 0.1 % ZrO2 decreased the crystallite size and BET particle size and increased the zeta potential, hence the stability of the nanofluids. The increase of stability increased the heat transfer coefficient of the Al2O3 nanofluids, making them suitable for heat trans...
Karbon aktif dan TiO2 mereduksi SO2 melalui proses adsorpsi dan fotokatalitik. Kedua senyawa ini ... more Karbon aktif dan TiO2 mereduksi SO2 melalui proses adsorpsi dan fotokatalitik. Kedua senyawa ini memiliki efektivitas adsorpsi rendah. Untuk meningkatkan aktivitas adsorpsi dilakukan kombinasi teknik adsorben dan fotokatalitik sehingga adsorpsi dapat optimal. Kombinasi dilakukan dengan membuat komposit karbon aktif/TiO2. Batubara dan semi-kokas dicampur dengan perbandingan 7:3 kemudian TiO2 ditambahkan dengan konsentrasi 1, 3, 6, 9 dan 15%. Karbon aktif/ TiO2 dikarbonisasi pada suhu 600 °C selama 1 jam dan diaktivasi pada suhu 900 °C selama 1 dan 2 jam di bawah aliran gas nitrogen. Hasil analisis fourier-transform infrared (FTIR) spectroscopy menunjukkan intensitas serapan gugus fungsi C=O naik sebesar 49,5% pada karbon aktif/TiO2 6% selama 1 jam dan 33,2% pada karbon aktif/TiO2 3% selama 2 jam. Gugus fungsi basa C=O mereduksi gas SO2 yang bersifat asam. Hasil X-ray diffraction (XRD) ditemukan kristal TiO2 anatas dan rutil. Koeksistensi kristal anatas dan rutil lebih efektif daripad...
The plate-like morphology of Bi4Ti3O12 get more attention from many researchers due to the effect... more The plate-like morphology of Bi4Ti3O12 get more attention from many researchers due to the effect of its morphology particle to some properties such as ferroelectric and photocatalyst. The molten salt synthesis is well known as the simple method to obtain the typical of particle morphology such as plate-like particle. The plate-like particle of Bi4Ti3O12 was succesfully synthesized using molten salt synthesis method at various molar ratio Bi4Ti3O12/NaCl of 1:4, 1:6, 1:8 and 1:10. Xray diffraction data showed that single phase of Bi4Ti3O12 was succesfully obtained. Based on scanning electron microscopy images, the higher of molar ratio Bi4Ti3O12/NaCl results the bigger of plate-like particle size of Bi4Ti3O12. Keywords— Bi4Ti3O12, molten salt synthesis method, molar ratio Bi4Ti3O12/NaCl, the plate-like particle
The use of motorized transportation in Indonesia is now proliferating. The higher the use of moto... more The use of motorized transportation in Indonesia is now proliferating. The higher the use of motorized vehicle-based transportation in an area, the higher the potential for air pollution. One of the air pollutants is a mixture of benzene, toluene, ethylbenzene, and xylene (BTEX). This study examines the effect of coconut shell-derived activated carbon adsorbent mass which is adjusted with different thicknesses on its adsorption ability for BTEX. The adsorbent is used to adsorb the emissions of the 1990 GL-Pro motorcycle with premium fuel. The results of gas chromatography-mass spectroscopy (GC-MS) show that motor vehicle emissions contain BTEX and other hydrocarbons. ANOVA variant analysis showed that the difference in mass of activated carbon in the range of this study did not provide a significant difference in BTEX adsorption.Keywords: adsorbent; motor vehicle emissions; BTEX pollutants; coconut shell
Metilen biru merupakan salah satu zat pewarna dalam limbah cair tekstil yang dapat merusak ekosis... more Metilen biru merupakan salah satu zat pewarna dalam limbah cair tekstil yang dapat merusak ekosistem perairan dan mempunyai nilai ambang batas 5 mg/L. Salah satu cara untuk mengolah MB dalam larutan yaitu dengan fotokatalisis mengingat sederhana, cepat, dan mudah diregenerasi. Namun, cara ini memiliki kekurangan yakni waktu pemisahan yang lama. Penambahan sifat magnetik ke dalam material fotokatalis yang kemudian disebut fotokatalis magnetik dapat mengatasi kelemahan dari fotokatalis konvensional. Dalam penelitian ini, fotokatalis magnetik berbasis komposit ZrO2-ZnFe2O4 telah berhasil disintesis menggunakan metode kopresipitasi sederhana dengan memanfaatkan mineral lokal pasir Zircon. Komposit yang dihasilkan dikarakterisasi menggunakan X-Ray Diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS), Surface Area Analyzer (SAA). Evaluasi terhadap kinerja fotokatalis diamati menggunakan metode spektrofotometri UV-Vis. ZrO2-ZnFe2O4 yang dihasilkan m...
This research aims to make a polypyrrole (PPy) membrane and crude extract of polyphenol oxidase (... more This research aims to make a polypyrrole (PPy) membrane and crude extract of polyphenol oxidase (PPO) as a membrane of mPPy/PPO apple extracts. The membrane of PPy/PPO-apple extract has been synthesized by the electrodeposition method. The electrolyte composition consists of a mixture of 0.10-0.20 M pyrrole (Py) and 50-100% PPO apple extract, which is stable using 50 mM of phosphate buffer solution at pH 6.80-7.00 and room temperature. The electrodeposition process is used 400 mesh steel gauze anode ST-304 and carbon plate cathode. Electrodeposition is carried out at potential = 5.00-6.00 V; current = 0.02-0.25 A; the distance from both electrodes = 1.00-2.00 cm for 300-500 seconds. The results from the deposition of PPy/PPO apple extract of the anode are a membrane of mPPy/PPO-apple extract, with total enzyme activity (U) = (957,1441, 2287 and 1754) using 2.00-5.00 mM phenol as a substrate which is measured based on the UV-visible spectrophotometric method. PPy and mPPy/PPO-apple e...
Methylene blue (MB) is one of the dyes used often by the textile industry. Therefore, MB residual... more Methylene blue (MB) is one of the dyes used often by the textile industry. Therefore, MB residual is contained in the textile industry waste. MB can irritate, leading to permanent eye and animal injuries; therefore, the textile industry waste concentration must be degraded before disposed to the environment. MB residual in textile industry waste can be treated with activated carbon adsorption. However, the adsorption method is less effective because the deposition takes a long time. This research aims to make activated carbon composites from banana peels and magnesium ferrite (BPAC/MgFe2O4) using the coprecipitation method to obtain activated carbon with magnetic properties (magnetic adsorbent). The obtained composite was characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-Ray (EDX), and Surface Area Analyzer. The adsorption performance of methylene blue on composites was evaluated with variations in pH, concentration, contact time, d...
Reducing a high-operating temperature of solid oxide fuel cell (SOFC) to intermediate temperature... more Reducing a high-operating temperature of solid oxide fuel cell (SOFC) to intermediate temperature SOFC (IT-SOFC, 500-750ºC) poses a great challenge in the sense of developing solid electrolyte at intermediate temperature range. In response to this, we report a novel composite La9.33Si6O26 (LSO) - Ce0.85Gd0.15O1.925 (CGO) in this study. The synthesis of LSO-CGO composite was carried out by combining LSO with CGO (9:1, 8:2, and 7:3 in weight ratio) using solid state reaction method. In order to get a dense pellet, all of the products were sintered at 1500°C for 3 h. The X-ray diffraction pattern of sintered pellets show typical patterns for both of LSO and CGO which indicate that the composite was successfully formed. The highest conductivity was detected in 7LSO-3CGO, i.e. 2.10×10-3 S cm-1 at 700 ○C and also has low activation energy (0.60 eV). This result suggests that the LSO-YSZ composites are good oxide ion conductors and may potentially be used as an alternative solid electrolyt...
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science), 2019
Monitoring the quality of the river is essentially to know the status of the periodic quality of ... more Monitoring the quality of the river is essentially to know the status of the periodic quality of the river. Good assessment of river water quality should use a combination of physical, chemical and biological parameters. One way that can be done to describe water quality in an area is the primary productivity in the water. Primary productivity is the amount of organic material produced by autotrophic organisms with the help of sunlight. Perifiton as a river microorganism, will provide dissolved oxygen (DO) through photosynthesis to maintain most of the life of the surrounding water, then Periphyton can respond quickly to environmental changes, this is an indicator of changing conditions (Gaiser 2008 and Lakewatch, 2000) in Brown and Wright (2016) Chemical reactions that occur in the aquatic environment also involve interactions between ions and other phases. Some important interactions in the waters are the occurrence of photosynthesis by algae and the exchange of dissolved solids w...
Currently in Indonesia, propellant research is still rarely carried out due to bureaucratic and b... more Currently in Indonesia, propellant research is still rarely carried out due to bureaucratic and budgetary problems. This study aimed to determine the optimum composition of propellant using local sources of nitrate compounds based on its combustion heat value and to study the effect of the composition on its combustion heat value. The propellant composition used in this study consists of oxidizing agents (local nitrate compounds), fuel (Aluminium), binder (polyester-based resin), and additive (catalyst). A bomb calorimetry method (ASTM D5865/5865-19) was used to determine the combustion heat value of the propellant. The results showed that the heat of combustion of local content nitrate compound-based propellants was high (> 1500 cal/g), adding binder to the propellant composition increases the heat of combustion. Ammonium nitrate-based propellant has the highest heat of combustion value of 3,788 cal/g. The optimum binder composition in the propellant was 33% (w/w). Based on this...
Three-layer Aurivillius compound bismuth titanate (Bi4Ti3O12) is well known for having interestin... more Three-layer Aurivillius compound bismuth titanate (Bi4Ti3O12) is well known for having interesting properties such as ferroelectric and photocatalyst. Many researchers reported that the unique plate-like shaped particle affecting ferroelectric and photocatalyst properties. The molten salt synthesis is the common simple method to obtain that unique morphology. In this research, Bi4Ti3O12 was synthesized using single molten salt NaCl at various temperatures, which is 800, 850, 900, and 950 oC. X-Ray Diffraction data showed that all obtained Bi4Ti3O12 have a B2cb space group with no impurities detected. The Raman spectra shows the characteristic vibration modes of Bi4Ti3O12 at 62, 117, 228, 269, 332, 364, 536, 851 cm-1. The plate-like shaped particle was confirmed by SEM analysis. Based on SEM images, the size of the particle increases as the synthesis temperature increased, which is due to the thermal effect on grain growth
The Journal of Pure and Applied Chemistry Research, 2021
Three-layer Aurivillius compound bismuth titanate (Bi4Ti3O12) is well known for having interestin... more Three-layer Aurivillius compound bismuth titanate (Bi4Ti3O12) is well known for having interesting properties such as ferroelectric and photocatalyst. Many researchers reported that the unique plate-like shaped particle affecting ferroelectric and photocatalyst properties. The molten salt synthesis is the common simple method to obtain that unique morphology. In this research, Bi4Ti3O12 was synthesized using single molten salt NaCl at various temperatures, which is 800, 850, 900, and 950 oC. X-Ray Diffraction data showed that all obtained Bi4Ti3O12 have a B2cb space group with no impurities detected. The Raman spectra shows the characteristic vibration modes of Bi4Ti3O12 at 62, 117, 228, 269, 332, 364, 536, 851 cm-1. The plate-like shaped particle was confirmed by SEM analysis. Based on SEM images, the size of the particle increased along with the synthesis temperature, which is due to the thermal effect on grain growth.
CaTiO3 as one of the perovskite-based photocatalysts has a band gap energy of 3.5 eV (~354 nm), t... more CaTiO3 as one of the perovskite-based photocatalysts has a band gap energy of 3.5 eV (~354 nm), thus will work at the ultraviolet light region. One of the strategies to decrease the band gap energy is doping metal. In this research, CaTiO3 was doped by Fe element as purposes to decreasing its band gap energy. Fe doped CaTiO3 compounds were synthesized using molten NaCl salt method. The diffractogram samples showed that the Fe-doped CaTiO3 crystal was successfully prepared. Meanwhile, the SEM images showed that the particle shape was regular polyhedral morphology, and doping Fe3+ caused the particle size to decrease and agglomerated. The UV-Vis DRS spectra showed that the Fe-dopant revealed the absorption light at visible range wavelength.
Reducing a high-operating temperature of solid oxide fuel cell (SOFC) to intermediate temperature... more Reducing a high-operating temperature of solid oxide fuel cell (SOFC) to intermediate temperature SOFC (IT-SOFC, 500-750oC) poses a great challenge in the sense of developing solid electrolyte at intermediate temperature range. In response to this, we report a novel composite La9.33Si6O26 (LSO) Ce0.85Gd0.15O1.925 (CGO) in this study. The synthesis of LSO-CGO composite was carried out by combining LSO with CGO (9:1, 8:2, and 7:3 in weight ratio) using solid state reaction method. In order to get a dense pellet, all of the products were sintered at 1500°C for 3 hours. The X-ray diffraction pattern of sintered pellets show typical patterns for both of LSO and CGO which indicate that the composite was successfully formed. The highest conductivity was detected in 7LSO-3CGO, i.e. 2.10×10-3 S cm-1 at 700oC and also has low activation energy (0.60 eV). This result suggests that the LSO-YSZ composites are good oxide ion conductors and may potentially be used as an alternative solid electroly...
IOP Conference Series: Earth and Environmental Science, 2021
Efforts to replace conventional fluids as coolants for heat transfers with new fluids are continu... more Efforts to replace conventional fluids as coolants for heat transfers with new fluids are continuously being made to improve heat transfer efficiency. Nanofluids are currently widely studied around the world as candidates for conventional fluids substitutes. In this research, the synthesis of Al2O3-ZrO2 nanocomposites for heat transfer nanofluid applications was carried out. The synthesis of the nanoparticles was conducted by the hydrothermal method. Here, we used ZrO2 to improve the characteristics of Al2O3. The results of XRD analysis showed that the nanocomposite had an Al2O3 gamma structure. The Al2O3 nanoparticles and Al2O3-ZrO2 nanocomposite have a crystallite size of 7.41 nm and 6.84 nm, respectively. The addition of 0.1 % ZrO2 decreased the crystallite size and BET particle size and increased the zeta potential, hence the stability of the nanofluids. The increase of stability increased the heat transfer coefficient of the Al2O3 nanofluids, making them suitable for heat trans...
Karbon aktif dan TiO2 mereduksi SO2 melalui proses adsorpsi dan fotokatalitik. Kedua senyawa ini ... more Karbon aktif dan TiO2 mereduksi SO2 melalui proses adsorpsi dan fotokatalitik. Kedua senyawa ini memiliki efektivitas adsorpsi rendah. Untuk meningkatkan aktivitas adsorpsi dilakukan kombinasi teknik adsorben dan fotokatalitik sehingga adsorpsi dapat optimal. Kombinasi dilakukan dengan membuat komposit karbon aktif/TiO2. Batubara dan semi-kokas dicampur dengan perbandingan 7:3 kemudian TiO2 ditambahkan dengan konsentrasi 1, 3, 6, 9 dan 15%. Karbon aktif/ TiO2 dikarbonisasi pada suhu 600 °C selama 1 jam dan diaktivasi pada suhu 900 °C selama 1 dan 2 jam di bawah aliran gas nitrogen. Hasil analisis fourier-transform infrared (FTIR) spectroscopy menunjukkan intensitas serapan gugus fungsi C=O naik sebesar 49,5% pada karbon aktif/TiO2 6% selama 1 jam dan 33,2% pada karbon aktif/TiO2 3% selama 2 jam. Gugus fungsi basa C=O mereduksi gas SO2 yang bersifat asam. Hasil X-ray diffraction (XRD) ditemukan kristal TiO2 anatas dan rutil. Koeksistensi kristal anatas dan rutil lebih efektif daripad...
The plate-like morphology of Bi4Ti3O12 get more attention from many researchers due to the effect... more The plate-like morphology of Bi4Ti3O12 get more attention from many researchers due to the effect of its morphology particle to some properties such as ferroelectric and photocatalyst. The molten salt synthesis is well known as the simple method to obtain the typical of particle morphology such as plate-like particle. The plate-like particle of Bi4Ti3O12 was succesfully synthesized using molten salt synthesis method at various molar ratio Bi4Ti3O12/NaCl of 1:4, 1:6, 1:8 and 1:10. Xray diffraction data showed that single phase of Bi4Ti3O12 was succesfully obtained. Based on scanning electron microscopy images, the higher of molar ratio Bi4Ti3O12/NaCl results the bigger of plate-like particle size of Bi4Ti3O12. Keywords— Bi4Ti3O12, molten salt synthesis method, molar ratio Bi4Ti3O12/NaCl, the plate-like particle
The use of motorized transportation in Indonesia is now proliferating. The higher the use of moto... more The use of motorized transportation in Indonesia is now proliferating. The higher the use of motorized vehicle-based transportation in an area, the higher the potential for air pollution. One of the air pollutants is a mixture of benzene, toluene, ethylbenzene, and xylene (BTEX). This study examines the effect of coconut shell-derived activated carbon adsorbent mass which is adjusted with different thicknesses on its adsorption ability for BTEX. The adsorbent is used to adsorb the emissions of the 1990 GL-Pro motorcycle with premium fuel. The results of gas chromatography-mass spectroscopy (GC-MS) show that motor vehicle emissions contain BTEX and other hydrocarbons. ANOVA variant analysis showed that the difference in mass of activated carbon in the range of this study did not provide a significant difference in BTEX adsorption.Keywords: adsorbent; motor vehicle emissions; BTEX pollutants; coconut shell
Metilen biru merupakan salah satu zat pewarna dalam limbah cair tekstil yang dapat merusak ekosis... more Metilen biru merupakan salah satu zat pewarna dalam limbah cair tekstil yang dapat merusak ekosistem perairan dan mempunyai nilai ambang batas 5 mg/L. Salah satu cara untuk mengolah MB dalam larutan yaitu dengan fotokatalisis mengingat sederhana, cepat, dan mudah diregenerasi. Namun, cara ini memiliki kekurangan yakni waktu pemisahan yang lama. Penambahan sifat magnetik ke dalam material fotokatalis yang kemudian disebut fotokatalis magnetik dapat mengatasi kelemahan dari fotokatalis konvensional. Dalam penelitian ini, fotokatalis magnetik berbasis komposit ZrO2-ZnFe2O4 telah berhasil disintesis menggunakan metode kopresipitasi sederhana dengan memanfaatkan mineral lokal pasir Zircon. Komposit yang dihasilkan dikarakterisasi menggunakan X-Ray Diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS), Surface Area Analyzer (SAA). Evaluasi terhadap kinerja fotokatalis diamati menggunakan metode spektrofotometri UV-Vis. ZrO2-ZnFe2O4 yang dihasilkan m...
This research aims to make a polypyrrole (PPy) membrane and crude extract of polyphenol oxidase (... more This research aims to make a polypyrrole (PPy) membrane and crude extract of polyphenol oxidase (PPO) as a membrane of mPPy/PPO apple extracts. The membrane of PPy/PPO-apple extract has been synthesized by the electrodeposition method. The electrolyte composition consists of a mixture of 0.10-0.20 M pyrrole (Py) and 50-100% PPO apple extract, which is stable using 50 mM of phosphate buffer solution at pH 6.80-7.00 and room temperature. The electrodeposition process is used 400 mesh steel gauze anode ST-304 and carbon plate cathode. Electrodeposition is carried out at potential = 5.00-6.00 V; current = 0.02-0.25 A; the distance from both electrodes = 1.00-2.00 cm for 300-500 seconds. The results from the deposition of PPy/PPO apple extract of the anode are a membrane of mPPy/PPO-apple extract, with total enzyme activity (U) = (957,1441, 2287 and 1754) using 2.00-5.00 mM phenol as a substrate which is measured based on the UV-visible spectrophotometric method. PPy and mPPy/PPO-apple e...
Methylene blue (MB) is one of the dyes used often by the textile industry. Therefore, MB residual... more Methylene blue (MB) is one of the dyes used often by the textile industry. Therefore, MB residual is contained in the textile industry waste. MB can irritate, leading to permanent eye and animal injuries; therefore, the textile industry waste concentration must be degraded before disposed to the environment. MB residual in textile industry waste can be treated with activated carbon adsorption. However, the adsorption method is less effective because the deposition takes a long time. This research aims to make activated carbon composites from banana peels and magnesium ferrite (BPAC/MgFe2O4) using the coprecipitation method to obtain activated carbon with magnetic properties (magnetic adsorbent). The obtained composite was characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-Ray (EDX), and Surface Area Analyzer. The adsorption performance of methylene blue on composites was evaluated with variations in pH, concentration, contact time, d...
Reducing a high-operating temperature of solid oxide fuel cell (SOFC) to intermediate temperature... more Reducing a high-operating temperature of solid oxide fuel cell (SOFC) to intermediate temperature SOFC (IT-SOFC, 500-750ºC) poses a great challenge in the sense of developing solid electrolyte at intermediate temperature range. In response to this, we report a novel composite La9.33Si6O26 (LSO) - Ce0.85Gd0.15O1.925 (CGO) in this study. The synthesis of LSO-CGO composite was carried out by combining LSO with CGO (9:1, 8:2, and 7:3 in weight ratio) using solid state reaction method. In order to get a dense pellet, all of the products were sintered at 1500°C for 3 h. The X-ray diffraction pattern of sintered pellets show typical patterns for both of LSO and CGO which indicate that the composite was successfully formed. The highest conductivity was detected in 7LSO-3CGO, i.e. 2.10×10-3 S cm-1 at 700 ○C and also has low activation energy (0.60 eV). This result suggests that the LSO-YSZ composites are good oxide ion conductors and may potentially be used as an alternative solid electrolyt...
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science), 2019
Monitoring the quality of the river is essentially to know the status of the periodic quality of ... more Monitoring the quality of the river is essentially to know the status of the periodic quality of the river. Good assessment of river water quality should use a combination of physical, chemical and biological parameters. One way that can be done to describe water quality in an area is the primary productivity in the water. Primary productivity is the amount of organic material produced by autotrophic organisms with the help of sunlight. Perifiton as a river microorganism, will provide dissolved oxygen (DO) through photosynthesis to maintain most of the life of the surrounding water, then Periphyton can respond quickly to environmental changes, this is an indicator of changing conditions (Gaiser 2008 and Lakewatch, 2000) in Brown and Wright (2016) Chemical reactions that occur in the aquatic environment also involve interactions between ions and other phases. Some important interactions in the waters are the occurrence of photosynthesis by algae and the exchange of dissolved solids w...
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