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Abstrak :
Telah dilakukan "Studi Diagram Fasa Pada Perlakuan Panas Isotherm KOMPOSISI Senyawa-Senyawa (Zr,Mg,Ca)Xoy" untuk membuat bahan dasar Keramik Zirkonia, dengan cara membuat berbagai variasi komposisi - paduan antara oksida logam Zr dengan oksida logam Mg dan Ca, kemudian dipelajari kondisi struktur mikronya setelah dibakar seperti fasa butir, fasa kristal dan tingkat oksidasinya; untuk mendapatkan persenyawaan (Zr,Mg,Ca)x0y dengan sifat-sifat fisika dan mekanika yang optimal bagi keramuk Zirkonia. Keramik Zirkonia adalah suatu jenis keramik baru yang mempunyai sifat fisika dan mekanik yang tangguh, bahan ini merupakan produk revolusi bagi industri otomotip, terutama untuk pemakaian pada bagian pembakaran yang membutuhkan ketahanan panas yang tinggi seperti klep, sliding bearing, camshaft, piston top, valve; selain itu juga untuk turbin gas terutama untuk penggunaan pada roda turbin, rotor, axle dan bearing. Demikian pula pada pabrik-pabrik bahan untuk bidang konstruksi, suku cadang dan peralatan. Dipilih jenis Oksida Kalsium dan Magnesium sebagai penstabil karena Kalsit, CaCO3, Axagonit, CaCO3 dan Magnecit, MgCO3 sebagai sumber CaO dan MgO banyak tersedia di Indonesia. Dan untuk memacu reaksi sintering hanya diperlukan temperatur pembakaran awal pada 850-1100°C (pre-aged) dan temperatur pemanasan selanjutnya (aged) pada 1250°C atau 1580°C selama waktu tertentu, dan kemudian didinginkan pada suhu kamar. "Fracture Energy yang terjadi ditransformasikan menjadi sifat fisis dan kekuatan mekanik yang tinggi. ...... A study of isotherm phase diagram, by heat treatment to chemical composition compound (Zr, Mg, Ca)xOy , as a basic material of Zirconia?s ceramic with the method of variation of proportional composition -- mix between metal oxide Zr, Mg and Ca ---; and then observed the condition of its micro structure after burning, i.e. grain particle phase, crystal phase and oxidation level to obtained the physical property and optimum mechanical strength of Zirconia?s ceramic of long-rounded type (Zr,Mg,Ca)py. Zirconia?s ceramic is a new type of ceramic, which has intrinsic physical property and robust mechanical strength. This material is a revolutionary product and has been used automotive industry, i.e. especially used in the ignation part which required high heat resistance such as klep, sliding bearing, camshaft, piston top, valve; as well as for the gas turbine as special material for the wheels turbine, rotor, axle and bearing. And also as industrial materials in the field of construction, machinery and spare parts equipments. Oxide Calcium and Magnesium have been used as stabilizer materials for Calcite, CaCO3, Aragonite, CaCO3 and Magnesite, MgCO3 since the sources of CaO and MgO are available abundantly in Indonesia. And for the spurred sintering reaction required only a burning temperature of 850-1100°C (pre-aged), and further heating at 1250°C or 1580°C (aged) for certain time, and then cooled at room temperature. The created energy in chemical reaction hag transforms the (Zr,Mg,Ca)xOy to a new intrinsic physical property and possessed a more robust mechanical strength.

Abstrak :
Bentonit asal Tapanuli telah dimodifikasi menjadi organoclay dengan menggunakan surfaktan kationik ODTMABr sebagai agen penginterkalasi. Kemudian produk hasil modifikasi dikarakterisasi dengan XRD, FTIR, SEM¬EDS, dan TGA. Sebelum preparasi, dilakukan fraksinasi bentonit sehingga didapat Fraksi 2 yang kaya montmorillonite (MMT) yang kemudian diseragamkan kation bebasnya dengan Na+ (menjadi Na-MMT). Selanjutnya menggunakan tembaga amin, nilai KTK Na diperoleh sebesar 65,5mek/100gram Na-MMT. Variasi jumlah ODTMABr yang digunakan untuk preparasi organoclay adalah 1,0; 2,0; dan 2,5 KTK. Pengaruh penambahan ODTMABr terhadap basal spacing, diamati dengan XRD low angel, menunjukkan bahwa terjadi peningkatan basal spacing dari 17.36 Å untuk Na-MMT menjadi 21.03 Å, 20.72 Å, dan 18.39 Å untuk 1,0; 2,0; dan 2,5 KTK. Kemampuan adsorpsi organoclay 1.0 KTK yang telah diprerparasi digunakan sebagai adsorben untuk fenol dan dibandingkan dengan Fraksi 2 dan Na-MMT. Data yang diperoleh pada kurva isotherm adsorpsi menunjukkan bahwa organoclay lebih efektif dalam menyerap fenol dan proses penyerapannya mengikuti kurva isotherm adsorpsi Freundlich. Bentonite from Tapanuli has been modified into organoclay using cationic surfactant as an agent ODTMABr as intercalation agent. Then the products were characterized by XRD, FTIR, SEM-EDS, and TGA. Before perparation, bentonite fractionation was performed in order to get Fraction 2 which is rich with montmorillonite (MMT) phase, and then is cation-exchanged with Na+ (called Na-MMT). Furthermore, using a copper amine methode, its cation exchange capacity (CEC) value was determined as 65.5 mek/100gram Na-MMT. Variation of ODTMABr concentration used for the preparation of organoclay is 1.0; 2.0 and 2.5 CEC. The effect of the addition of ODTMABr to Na-MMT?s basal spacing, observed by low angel XRD, shows an increase in basal spacing of initially 17.36 Å for Na-MMT to 20.85 Å, 21.03 Å, and 18.02 Å for 1.0; 2.0; and 2.5 CEC. 1.0 CEC organoclay adsorption capacity was observed by using it as adsorbent for phenol and compared with the capacity of Fraction 2 and Na-MMT. Data obtained on the adsorption isotherm curve shows that the organoclay is more effective in adsorbing phenols and the adsorption process follows Freundlich adsorption isotherm curve.

Abstrak :
The present study explores the effectiveness of typha domingensis leaf powder for simultaneous removal of aluminium,iron,zinc and lead ions from aqueous solution....

Abstrak :
Molecularly imprinted polymers (MIPs) have been the most convenient and selected methods in detection and extraction for many types of specific targets in various fields. MIPs were prepared by mixing template molecule with functional monomer in the presence of cross-linker, solvent and initiator. The selectivity of MIPs is strongly influenced by the types of functional monomer, solvent and polymerization process used. Pyrogallol-imprinted polymer (Py-IP) and non-imprinted polymer (NIP) were synthesized via precipitation polymerization using 4-vinylpyridine (4-VP), divinylbenzene (DVB) and azobisisobutyronitrile (AIBN) as functional monomer, cross-linker and initiator, respectively. Pyrogallol (Py) was used as a target molecule. The synthesized polymers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and UV-Visible Spectroscopy (UV-Vis). In this study, adsorption capacity was measured by the dosage effect, contact time and selectivity study. Results showed that maximum adsorption capacity by Py-IP is above 50%. The Selectivity study shows that k? is >1, which indicates that Py-IP has a good selectivity towards pyrogallol. Therefore, it has a good potential to be used as an adsorbent.

Abstrak :
Molecularly imprinted polymers (MIPs) have been the most convenient and selected methods in detection and extraction for many types of specific targets in various fields. MIPs were prepared by mixing template molecule with functional monomer in the presence of cross-linker, solvent and initiator. The selectivity of MIPs is strongly influenced by the types of functional monomer, solvent and polymerization process used. Pyrogallol-imprinted polymer (Py-IP) and non-imprinted polymer (NIP) were synthesized via precipitation polymerization using 4-vinylpyridine (4-VP), divinylbenzene (DVB) and azobisisobutyronitrile (AIBN) as functional monomer, cross-linker and initiator, respectively. Pyrogallol (Py) was used as a target molecule. The synthesized polymers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and UV-Visible Spectroscopy (UV-Vis). In this study, adsorption capacity was measured by the dosage effect, contact time and selectivity study. Results showed that maximum adsorption capacity by Py-IP is above 50%. The Selectivity study shows that k’ is >1, which indicates that Py-IP has a good selectivity towards pyrogallol. Therefore, it has a good potential to be used as an adsorbent.

Abstrak :
The investigation of adsorption isotherms is a prime factor in the ongoing development of adsorption cycles for a spectrum of advanced, thermally-driven engineering applications, including refrigeration, natural gas storage, and desalination processes. In this work, a novel semi-empirical mathematical model has been derived that significantly enhances the prediction of the steady state uptake in adsorbent surfaces. This model, a combination of classical Langmuir and a novel modern adsorption isotherm equation, allows for a higher degree of regression of both energetically homogenous and heterogeneous adsorbent surfaces compared to several isolated classical and modern isotherm models, and has the ability to regress isotherms for all six types under the IUPAC classification. Using a unified thermodynamic framework, a single asymmetrical energy distribution function (EDF) has also been proposed that directly relates the mathematical model to the adsorption isotherm types. This fits well with the statistical rate theory approach and offers mechanistic insights into adsorption isotherms.

Abstrak :
Penyimpanan gas metana hingga saat ini terus dikembangkan agar dapat dimaksimalkan di tingkat global. Selain melalui metode LNG atau CNG, pengembangan metode penyimpanan metana melalui adsorbed natural gas (ANG) menjadi salah satu yang dioptimalkan karena parameter penyimpanannya yang ditetapkan hanya pada temperatur ruangan dan tekanan sekitar 35 Bar. Dengan dasar tersebut, salah satu upaya pengoptimalan penyimpanan metana dengan metode ANG adalah dengan mengembangkan adsorben yang memiliki kapasitas adsorpsi tinggi namun ramah lingkungan. Maka dari itu, dikembangkan Bio-MOF Zinc glutamate. Adsorben berbasis Zinc telah dikenal sangat baik kemampuannya untuk aplikasi adsorpsi dan penyimpanan gas. Dalam penelitian ini, Bio-MOF tersebut disintesis dengan metode sonochemical dengan 7 buah variasi (A1, A2, A3, A4, A5, B, dan C) yang mana tiap variasinya dikarakterisasikan dengan BET, SEM, XRD, dan TGA untuk mendapatkan informasi yang terperinci terkait adsorben tersebut. Diketahui bahwa adsorben ini memiliki BET Surface Areasebesar 8.389 m2/g. Kemudian, dilakukan uji adsorpsi isotermal gas metana dari Bio-MOF Zinc glutamate pada temperatur 27, 35, dan 50. Rentang tekanannya adalah 2 Bar-35 Bar. Berdasarkan hasil uji adsorpsinya, Kapasitas penyerapan puncak pada 27  bertekanan 35 Bar adalah 0.0553 g/g, kemudian pada temperatur 35  mencapai 0.0513 g/g, dan terakhir pada temperatur 50  mencapai 0.0412 g/g. Dilakukan fitting korelasi adsorpsi isotermal melalui korelasi Langmuir, Freundlich, dan Sips yang menunjukkan bahwa korelasi Sips memiliki fitting terbaik dan didapat panas adsorpsi isosterik sebesar 7.448 kJ/mol dengan persamaan Clausius-Clapeyron. ......Methane gas storage is still being researched in order to exploit its global potential. Aside from using LNG or CNG, the development of methane storage solutions using adsorbed natural gas (ANG) is one that is optimum because the storage settings are simply established at room temperature and a pressure of roughly 35 Bar. Based on this, one of the initiatives to optimize methane storage using the ANG technique is to design an ecologically friendly adsorbent with a high adsorption capacity. As a result, Bio-MOF Zinc glutamate was created. Zinc-based adsorbents are widely known for their capacity to absorb and store gas. The Bio-MOF was synthesized using the sonochemical approach with seven variations (A1, A2, A3, A4, A5, B, and C), each of which was characterized using BET, SEM, XRD, and TGA to gain essential information. details regarding the adsorbent. This adsorbent has a BET Surface Area of 8.389 m2/g, which is known. Then, at temperatures of 27°C, 35°C, and 50°C, an isothermal adsorption test of methane gas from Bio-MOF Zinc glutamate was performed. The pressure range is from 2 bar to 35 bar. Based on the sorption test results, the maximum absorption capacity was 0.0553 g/g at 27°C and 35 bar pressure, and then reached 0.0513 g/g at a temperature of 35°C. g/g and finally reached 0.0412 g/g at a temperature of 50°C. Isothermal adsorption correlation fits were performed using the Langmuir, Freundlich, and Sips correlations and found that the Sips correlation was the best fit, yielding an isothermal heat of adsorption of 7.448 kJ/mol using the Clausius-Clapeyron equation was shown.

Abstrak :
Agricultural waste has increased colossally with development in agricultural production causing environmental nuisance and degradation. Utilization of coconut husks, one of such type of waste, as a biosorbent for polluted surface water treatment, was considered in this study. Polluted surface water was gently passed through two similar columns loaded with 100 and 200 g of coconut husk char respectively. The treated water samples collected after 30, 60, 90, 120 and 150 mins were examined for SO42-, NO3- and PO43- ions concentration. Removal efficiency for SO42-, NO3- and PO43- ions on 100 g coconut husk char after 150 mins detention time were 70, 78 and 91% respectively. Freundlich isotherm model gave a better description of the data (R2 > 0.96). Sorption data was well described by second order pseudo kinetics (R2 > 0.85). An amount of 100 g of the biosorbent has a strong affinity for these types of ion removal in contaminated water. Coconut husk char as a biosorbent is a panacea to significant concentrations of polyatomic ions in polluted surface water.

Abstrak :
Agricultural waste has increased colossally with development in agricultural production causing environmental nuisance and degradation. Utilization of coconut husks, one of such type of waste, as a biosorbent for polluted surface water treatment, was considered in this study. Polluted surface water was gently passed through two similar columns loaded with 100 and 200 g of coconut husk char respectively. The treated water samples collected after 30, 60, 90, 120 and 150 mins were examined for SO42-, NO3- and PO43- ions concentration. Removal efficiency for SO42-, NO3- and PO43- ions on 100 g coconut husk char after 150 mins detention time were 70, 78 and 91% respectively. Freundlich isotherm model gave a better description of the data (R2 > 0.96). Sorption data was well described by second order pseudo kinetics (R2 > 0.85). An amount of 100 g of the biosorbent has a strong affinity for these types of ion removal in contaminated water. Coconut husk char as a biosorbent is a panacea to significant concentrations of polyatomic ions in polluted surface water.

Abstrak :
The abundance of graphite waste can be processed into valuable materials; one alternative is by making it into an adsorbent. Graphite-based adsorbent modification can be accomplished by adding magnetite nanoparticles Fe3O4. The addition of magnetite nanoparticles has been reported to improve the adsorption ability of the graphite waste. In this study, we have developed a new carbon dioxide (CO2) adsorbent based on graphite waste modified with magnetite nanoparticle Fe3O4. The Fe3O4 were prepared using an impregnation technique. The graphite/Fe3O4 composites were characterized by scanning electron microscopy with an energy-dispersive X-ray system (SEM-EDX) and Brunauer, Emmett, and Teller (BET). The CO2 adsorption performance was evaluated using an isothermal adsorption method at various temperatures (30, 35, and 45oC) and pressures (3, 5, 8, 15, and 20 bar). This resulted in graphite with different magnetite modification levels, namely non-modified graphite (GNM), a graphite/Fe3O4 20% (w/w) composite (G/Fe3O4 20%), and a graphite/Fe3O4 35% (w/w) (G/Fe3O4 35%), which indicated that the largest adsorption capacity is 10.305 mmol.g-1 at 30oC and 20 bar pressure for the G/Fe3O4 20% composite. This finding further revealed that modifying graphite waste with magnetite nanoparticles Fe3O4 has been proved to increase the capacity for adsorbing CO2 gas.