Jurnal Rekayasa Kimia & Lingkungan
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Sintesis membran Poliuretan dari Karagenan dan 2, 4 Toylulene diisosianat
Get PDFThis research studied the synthesis of Polyurethane (PU) Membrane from Carrageenan and 2,4 toylulene diisocyanante (TDI). The PU membrane made from the Gracilaria sp of red seaweed has rendement of 60.5% from the total weight of the dried sea grass. The produced Carrageenan has pure properties with containing many OH groups which can be used to synthesize membrane. The dope solution to produce good membrane was made at the temperature of 60 oC for the reaction of 5 minutes by varying concentration of carrageenan 5-35 % (b/v). PU membrane was constructed using petri dish with the thickness of about 0.1 mm. To control the thickness of the membrane, the volume of dope solution was used about 12 mL, and the membrane was produced with 10 cm in diameter. The membrane had been synthesized at the temperature of 60 oC with varied concentration of Carrageenan 15% (b/v) to the toylulene diisocyanate (TDI). The produced membrane has the optimal properties with the tensile strength of 340 kgf/mm2, the elongation percentage of 9%, the glass temperature transition of 243.6 oC and the melting point of 423.02 oC. The optimum PU membrane obtained was good in mechanical and physical properties, strong, elastic and transparent.Keywords: carrageenan, flux, membrane, polyurethane, rejection factor, TD
Produksi Pati Termodifikasi dari Beberapa Jenis Pati
Get PDFStarch is modified for three reasons. First, modified starch provides functional attributes in food applications that native starches normally cannot provide. Second, starch is abundant and readily available. Third, starch can provide an economic advantage in many applications. Process for the production of modified starch comprised the steps of (1) extracting starch from potato and sweet potato, and (2) modifying the starch to produced pre-gelatinized, acid modified, and cold water swelling starch. Tapioca gives the best performance when modified by pre-gelatinization and cold water swelling. The characteristic of the pre-gelatinized tapioca were swelling power 979,782%, water holding capacity 480,391%, moisture contents 8.48%, ash content 0,006%, dan yield 93,358%.Keywords: acid modified, cold water swelling starch, modified starch, pre-gelatinize
Adsorpsi Ion Logam Cu(II) Menggunakan Lignin dari Limbah Serbuk Kayu Gergaji
Get PDFAdsorption of heavy metal ion Cu(II) onto modified lignin from sawdust waste have been presented. The ability of lignin from sawdust waste to adsorb the copper ion has been evaluated by varying adsorption time, pH of solution, and adsorption capacity. The concentration of copper ion was measured by atomic adsorption spectrometer. The result showed that the optimum condition of ion Cu(II) by lignin were achieved at adsorption time of 15 minutes, pH of solution of 6, and copper concentration of 20 mg/L with adsorption efficiency of 99,3 %. In this study, the maximum capacity of 15,43 mg/g and equilibrium constant of 754,96 were achieved.Keywords: adsorpsi, ion tembaga, lignin, limbah serbuk kayu gergaj
Pembuatan Katalis Cu/ZnO/Al2O3 untuk Proses Steam Reforming Metanol menjadi Hidrogen sebagai Bahan Bakar Alternatif
Get PDFStudy on the use of copper zinc oxide supported on alumina catalyst for steam reforming of methanol to hydrogen has been done. The aim of this work is to study the catalytic properties of copper based catalysts used in the steam reforming of methanol. This method is known as one of the most favorable catalytic processes for producing hydrogen on-board. The catalyst was prepared by impregnation method with Cu loading of 5%, 10%, and 15%,. The X-ray diffraction pattern shows that the catalyst compositions are Cu, CuO, ZnO, and Al2O3. The reactions were carried out in the fixed bed tubular reactor operating at temperatures of 150oC, 200oC, 250oC, 300oC, and 350oC and atmospheric pressure. The product was analyzed using Shimadzu Gas Chromatography GC 8A with mole sieve 5A and porapak-N column 80/100 mesh. The performance of the catalyst shows that the highest methanol conversion was 86% over Cu/ZnO/Al2O3 catalyst with 15% of Cu loading. The selectivity and yield of hydrogen was 66% and 57% respectively over Cu/ZnO/Al2O3 catalyst with 15% of Cu loading. Selectivity of carbon dioxide is 18% over Cu/ZnO/Al2O3 catalyst with 15% of Cu loading at 300oC.Keywords: alumina oxide catalyst, copper zinc oxide, hydrogen, impregnatio
Analisis Logam Berat Pb dan Cd dalam Sampel Ikan dan Kerang secara Spektrofotometri Serapan Atom
Get PDFThe analysis of heavy metals Pb and Cd concentrations in fish and oyster have been carried out by atomic absorption spectrophotometer (AAS) method. The wet digestion method was used for preparation sample prior to AAS detection. Sample was collected from three different location rivers at Lamnyong, Pantee Pirak and Lumbago. The result showed that the Pb and Cd concentration in fish and oyster at difference location were obtained not difference significantly. Pb and Cd contents in fish and oyster were found below lethal concentration. The AAS instrument was still valid to use as the instrument which is obtained of accuration of 0.65% and precise of 0,019 ppm still lower than threshold value of 1% and 0.04 ppm.Keywords: atomic absorbance spektrophootometry, fish, kerang, heavy meta
Water Quality Assessment in the Tsunami Areas of Banda Aceh
No full textWater quality assessment in the tsunami-affected areas conducted in Meuraxa and Kutaradja sub-districts in the area of Banda Aceh City. Water samples were collected in October 2006 from dug wells of tsunami-affected areas. These were characterized for various physical and chemical parameters. Water quality in the selected areas has shown that the surface water was contaminated due to the tsunami. Total Dissolved Solid, Total Suspended Solid, Acidity, and salinity were high in the affected areas indicating saline water intrusion into surface water tables. Dug wells in the highly affected locations showed higher values of heavy metal ions like Mn, Pb, Cu, Fe, Zn, and Cu compared to the reference points. No ion Hg was found in all samples. Keywords: Banda Aceh, heavy metals, tsunami, water qualit
Studi Pembuatan dan Karakteristik Sifat Mekanik dan Hidrofobisitas Bioplastik dari Pati Sorgum
Get PDFThis research investigated the utilization of sorghum starch and chitosan as basic material for preparation of biodegradble plastic. The optimum conditions for the formation of biodegradble plastic and the effect of starch-chitosan formulation on mechanical properties of the biodegradable plastic were studied. The experiments were conducted by varying concentration sorbitol as plasticizer (i.e. 20%, 25%, 30%, and 40% dry weight), ratio starch to chitosan (i.e. 6:4, 7:3, 8:2, 9:1, 10:0 g/g) and at ranging gelatinuous temperature of 65-95oC. The results showed that the optimum conditions were obtained at starch:chitosan mass comparison of 7:3 and sorbitol concentration of 20%. The mechanical properties of the biodegradable plastic produced at gelatinuous temperature of 95oC were: tensile strength of 6,9711 Mpa, elongation percentage of 16,48, modulus young of 42,48 Mpa, and water resistance of 36,825%.Keywords: bioplastic, chitosan, plasticizer, sorgum, sorbito
Production of Valuables Organic Acids from Organic Wastes with Hydrothermal Treatment Process
Get PDFThis article reports production of valuables organic acids from the hydrothermal treatment of representative organic wastes and compounds (i. e. domestic sludge, proteinaceous, cellulosic and plastic wastes) with or without oxidant (H2O2). Organic acids such as acetic, formic, propionic, succinic and lactic acids were obtained in significant amounts. At 623 K (16.5 MPa), acetic acid of about 26 mg/g-dry waste fish entrails was obtained. This increased to 42 mg/g dry waste fish entrails in the presence of H2O2. Experiments on glucose to represent cellulosic wastes were also carried out, getting acetic acid of about 29 mg/g-glucose. The study was extended to terephthalic acid and glyceraldehyde, reaction intermediates of hydrothermal treatment of PET plastic wastes and glucose, respectively. Studies on temperature dependence of formation of organic acids showed thermal stability of acetic acid, whereas, formic acid decomposed readily under hydrothermal conditions. In general, results demonstrated that the presence of oxidants favored formation of organic acids with acetic acid being the major product. Keywords: hydrothermal treatment, organic acids, organic wastes, oxidant, supercritical water oxidatio
Analisis Kinetika Pertukaran Ion NH4+ dan H+ pada Zeolit Alam Lampung dengan Shrinking Core Model
Get PDFIon exchange process between ion NH4+ and H+ by using zeolite as its ion exchanger is one of methods to purify water from ammonium ion content. Natural zeolites are chosen as ion exchanger because it is abundantly provided in Indonesia, especially in Lampung. The influences of reaction temperature and stirrer speed toward reaction rate constant, mass transfer coefficient and effective diffusivity in batch ion exchange process, were analysed by using shrinking core model. Processes run by mixing zeolite and ammonium solution in a stirred tank at 30, 40 and 50oC with stirrer speed variation of 700, 800 and 900 rpm. Every 5 up to 60 min, the sample was taken for ammonium ion analyses. The results show that mass transfer, intraparticle diffusion and ion exchange reaction resistance influenced the overall rate of reaction. The results also show that reaction temperature and stirrer speed influenced the reaction rate constant, mass transfer coefficient and effective diffusivity. The correlations of them are stated in simple empirical equation. Shrinking core model was good to describe the ion exchange kinetics between NH4+ and H+ ion in natural zeolite from Lampung with the average error range of 1,15 % 3,71%.Keywords: ion exchange kinetics, Lampung natural zeolite, shrinking core model
Produksi Etanol Proses Sinambung dengan Schizosaccharomyces Pombe
Get PDFEthanol is one of fermentation products which are mostly used as solvent in pharmaceutical and chemical industries. Ethanol production by fermentation generally uses yeast from Saccharomyces and Schizosaccharomyces. The fermentation of ethanol by both processes yields great quantities of ethanol. Optimum productivity in ethanol fermentation by continuous process using Schizosaccharomyces pombe was obtained at initial substrate concentration of 200g/L, with value as much of 7.342g/Lhour at dilution rate of 0.1/hour, 4.643 g/Lhour at dilution rate of 0,06/hour and 3.213g/Lhour at dilution rate of 0.04/hour. The highest value of ethanol coefficient YP/S obtained at initial substrate concentration of 100g/L was as much of 0.461 at batch process, while values of ethanol coefficient YP/S obtained were in the range of 0,477-0,511 in continuous process, which were higher than those of batch process.Keywords: continuous process, ethanol, schizosaccharomyces pomb