Jurnal Rekayasa Kimia & Lingkungan
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The Study Effect of Fill and React Period Change on the Performance of the Sequencing Batch Reactor
Get PDFThe operation of the sequencing batch reactor (SBR) can be optimized by controlling the dissolved oxygen concentration, the dosage of external carbon, nitrification and denitrification, and the phase length of aeration (fills and react period). In this work, the analyses and tested with open loop identification the effect of fill and react period change on the performance of the SBR were studied. The process dynamic has been tested to determine the effect of Fill (tf) and React (tr)period changes on soluble substrate (Ss), soluble intermediate product (Ps), inert substrate (Si), particulate organics concentration (Xs), active biomass concentration (Xa), inert biomass concentration (Xi), the total biomass concentration (Xto) and the effluent chemical oxygen demand (COD) concentration in the SBR. In all simulations the total Fill and React time were set at 6 h, with the Fill time varied at 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, and the corresponding react time set at 5.5 h, 5 h, 4.5 h, 4 h, 3.5 h, and 3 h, respectively.Keywords: fill time and reaction time, sequencing batch reactor, wastewater treatmen
Kajian tentang Kemungkinan Pemanfaatan Bahan Serat Ijuk sebagai Bahan Penyerap Suara Ramah Lingkungan
Get PDFThe probability of application of palm fibre from arenga pinnata appear as best treatment for sound absorption material which can be used in controlling noise. The objective of this study is to determine sound absorption coefficient value of palm fibre through a testing the absorbent material, by applying sabine reverberation time formulation in reverberation chamber at Thermal and acoustics laboratory Syiah Kuala University. Result of this study show that sound absorption coefficient value is obtained 0.97, at 2000 Hz. Whereas thickness of material 20 cm with density of 150 kg/m3. Addition of density can increase sound absorption coefficient value in frequency range 1/3 octave. Proven that a comparison palm fibre and artificial material and consequently palm give better quality values because it economic value and friendly environment.Keywords: palm fiber, reverberation chamber, sound absorption coefficien
Pengaruh Pengekstrakan pada Kekuatan Kayu: Damar Batu, Kempas, dan Durian
Get PDFThe objective of this research is to determine strength rate of Damar Batu/Balau (Shorea spp.), Kempas (Kompassia malaccensis), and Durian (Durio spp.) before and after extraction. For this purpose, three solvents were used in sequence to extract the wood which are acetone pentane, and mixture of hexane, acetone, and water (HAW) with volume ratio 55:44:2. Studies on the wood comprises of tensile, bending, and impact test. The tests are conducted based on method of ASTM D 3500 90, ASTM D 3043 95, and ASTM D 1e43 94 for tensile, bending, and impact test, respectively. The result showed that Damar Batu/Balau has higher strength compared to Kempas and Durian Woods. All the wood samples after extraction show a slight decreasing in tensile strength, tensile extension, and flexural stress, whereby modulus tensile, modulus flexural, and impact strength increases.Keywords: bending, extraction, impact, tensil
Pengaruh Waktu Tinggal dan Umur Tanaman pada Biosorpsi Ammonia oleh Tanaman Air Enceng Gondok (Eichhornia Grassipes)
Get PDFAmmonia biosorption by using Enceng Gondok, Eichhornia crassipes, was conducted in outdoor laboratory with objective to study the influence residence time and plant age to ammonia biosorption rate. The research uses reactor test consisting of wet land and sludge. Enceng Gondok is planted on reactor test flown by ammonia as bacth with relatif low enough concentration (2 mg/L), water height 20 cm, plants number in each reactor of 4 stems with variatious plants length 10, 20, 30, and 40 cm, and various residence time 2, 4, 6, and 8 days. Each test conducted was completed by controlling reactor. Research result showed that maximun biosorption occurs at 2 days culturization; ammonia biosorption rate by roots increases as residence time increases. Residence time 2, 4, 6 and 8 days can decrease ammonia concentration up to 1.568 mg/l, 0.245 mg/l, 0.204 mg/l (10%), and 0.022 mg/l, respectively, at plant length 10 cm. Further, research results showed that the more the plants age, the larger the biosorption by plant.Keywords: ammonia biosorption, enceng gondok, plants age, residence tim
Preparasi Katalis Cu/Silika Gel dari Kristobalit Alam Sabang serta Uji Aktivitasnya pada Reaksi Dehidrogenasi Etanol
Get PDFCu/Silica gel catalyst preparation by using silica content which is obtained from Sabang natural crystobalit has been done. Isolated silica from crystobalit is reacted with natrium hidroxide to produce silicate natrium that reacted further with sulphate acid to produce silica gel. Silica gel is characterized by infra red spektroscopy dan BET test. BET test result showed that silica gel obtained has specific surface area 260,04 m2/gram and ion Cu impregnation into silica gel pores produce Cu/silica gel catalyst with spesific surace area 158,53 m/gram ith Cu2+ metal content = 193 ppm. Catalyst activation test Cu/silica gel at dehidrogenation reaction of etanol to produce asetaldehide was done at temperature 100oC 300oC. Reseach showed that the highest asetaldehide consentration (20,24%) is obtained at temperature 300oC. Keywords: asetaldehide, crystobalit, Cu/silica gel, dehidrogenation, ethano
Esterification of Free Fatty Acid in Crude Palm Oil Off Grade
Get PDFThe esterification of free fatty acids (FFA) found in crude palm oil (CPO) off grade with methanol is a promising technique to convert FFA into valuable fatty acid methyl ester (FAME, biodiesel) and obtain a FFA-free oil that can be further transesterified using alkali bases. In this work, the effects of the main variables involved in the esterification process i.e. alcohol to oil molar ratio, reaction temperature, agitation speed and the initial amount of FFA of oil, were studied in the presence of sulphuric acid as catalyst at concentration of 1%-w. The experimental results show that the esterification process could lead to a practical and cost effective FFA removal unit in front of typical oil transesterification for biodiesel production.Keywords: CPO off grade, esterification, free fatty aci
Kinerja Katalis Paduan ZnO dengan Tembaga dan Logam-Logam Golongan VIII pada Steam Reforming Etanol menjadi Hidrogen
Get PDFSteam reforming of ethanol to H2 using ZnO catalyst with promotor metal, i.e. copper or metal group VIII (Pd, Pt and Ni) has been investigated. Catalysts performances are tested further at micro reactor operating at atmosphere pressure. Ethanol solution 20% is injected to reactor at rate of 2 ml/jam and is mixed with nitrogen flow at 25 ml/menit. XRD analysis shows active phases existence of each promotor for produced catalyst. Reaction product includes H2, CO2, and a nonidentified component. Selectivity of H2 fromation depends on chosen promotor metal types, where the selectifity decreases as follows: Pt , Pd , Cu Ni. Reaction temperature and promotor concentration also influence selectifity H2. For catalyst 1% Pd/ZnO and 1% Pt/ZnO, selectivity H2 was optimum at temperature reaction 450oC. Whereas Pd promotor concentrations increasing from 1% to 5% improves H2 selectivity.Keywords: ethanol, hidrogen, steam reforming, Zn
Gas Absorption by Alkaline Solution in a Cyclone Scrubber: Experimental and Modeling Study
Get PDFExperimental and modeling studies have been conducted on a CO2 absorption in a cyclone scrubber operated at room temperature. The effects of parameters such as the initial concentration of alkali in the solution and the liquid gas ratio on the CO2 absorbed flux were experimentally and theoretically investigated. A theoretical study has been performed using a mathematical model based on the absorption in the liquid droplet with instantaneous reaction, in the inlet duct of the cyclone and in the cyclone itself. The results from the model were compared with experimental data and showed satisfactory agreement. Keywords: CO2 removal, mathematical model, wet cyclone scrubbe
The Effect of Filler Content on Mechanical Properties of Polypropylene/Clay Nanocomposites
Get PDFThis study investigated the effect of filler content on mechanical properties of polypropylene. There are synthesis clay and un-synthesis clay used as filler content. Different ratio of clay in polypropylene to study which ratio has a better mechanical property. The tensile test was carried out using INSTRON5565 and the maximum stress, strain, and modulus of elasticity observed. The experimental results showed that polypropylene/clay nanocomposite has a higher maximum stress compare to pure polypropylene and un-synthesis clay. Besides that modulus of elasticity of specimen calculated and finds that it increased with increment filler content and strain did not affect by filler. The synthesis clay filled into polypropylene will have a better mechanical property. Keywords: nanocomposite, polypropylene, synthesis cla
Pemisahan Unsur Samarium dan Yttrium dari Mineral Tanah Jarang dengan Teknik Membran Cair Berpendukung (Supported Liquid Membrane)
Get PDFhe increasing use of rare earth elements in high technology industries needs to be supported by developmental work for the separation of elements. The research objective is fiercely attracting and challenging considering the similarity of bath physical and chemical properties among these elements. The rate separation of samarium and yttrium elements using supported liquid membrane has been studied. Polytetrafluoroethylene (PTFE) with pore size of 0.45 m has been used as the membrane and di(2-ethylhexyl) phosphate (D2EHP) in hexane has been used as a carrier and nitric acid solution has been used as receiving phase. Result of experiments showed that the best separation rate of samarium and yttrium elements could be obtained at feeding phase of pH 3.0, di(2-ethylhexyl) phosphate (D2EHP) concentration of 0.3 M, agitation rate of 700 rpm, agitation time of 2 hours, and nitric acid and its solution concentrations of 1.0 M and 0.1 M, respectively. At this condition, separation rates of samarium and yttrium were 64.4 and 67.6%, respectively. Keywords: liquid membrane, rare earth elements, samarium, yttriu