Jurnal Rekayasa Kimia & Lingkungan
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Aktivitas Antioksidan Ekstrak Etanol Daun Ubi Jalar Ungu (Ipomea batatas L.) Hasil Budidaya Daerah Saree Aceh Besar
Get PDFThis research was aimed to investigate the antioxidant activity of purple sweet potato leaves cultivated in Saree, Aceh Besar. The study was conducted in two stages. The first stage included sampel preparation, phytochemical test, max determination, testing of antioxidant activity by reducing power method, and TLC analysis. In stage 2 purification using column chromatography, phytochemical test, and antioxidant activity test were performed. The sample was dissolved by using 70% ethanol and 1.5 N HCl with a ratio of 85:15 (v/v). Phytochemical test results showed that the sample consisted of not only flavonoids but also tannins. The Rf value for both sample and standard are respectively 0.55 and 0.61 with absorbance value of 0.826 and 0.845. The sample was then purified using column chromatography and 25 fractions were grouped based on the color intensity abbreviated as FA, FB and FC. Photochemical test was then conducted to examine the purity of obtained fraction and FB was found to be relatively purer than other fractions. Reducing power test of FB with variation of weight 10 mg, 20 mg, 30 mg, 40 mg, and 50 mg gave the percentage inhibition 64.1, 6.7, 67.9, 70.3 and 73.6, respectively, while the percentage value of - tocopherol at simmilar weight variation are 32.1, 36.7, 43.5 and 50.2%. From the result obtained, it can be concluded that the antioxidant activity of ethanol extract of thick purple sweet potato leaves is higher than -tocopherol.Keywords: antioxidant activity, purple sweet potato leaves, reducing powe
Sanitary Landfilling A Key Component of Waste Management
Get PDFIn many affluent countries waste management is experiencing a fast transition from landfilling to sophisticated recycling and waste to energy plants. Thus, landfilling of waste becomes less important in these countries. The present paper discusses whether a similar development will take place in transition economies, or waste management systems will mainly rely on landfilling in the near future. For this purpose, the current waste management practices and associated environmental impacts as well as the economic situation of different countries in economic transition are analyzed. Based on the status quo, scenarios for improving waste management are developed and evaluated. Criteria for evaluation are economic parameters, and indicators pointing out if the goals of waste management (protection of human health and the environment, the conservation of resources), are reached. Based on the results of selected case studies, it is shown that for regions that can afford less than 20 /capita and year for waste management, landfilling will remain a key component of waste management, since other disposal options such as waste to energy or mechanical biological pretreatment are too expensive. In addition, the results indicate that in many of these countries waste collection still represents a main challenge
Produksi Ramnolipid dan Polihidroksialkanoat secara Simultan dari Produk Samping Industri Biodiesel dengan Bahan Baku CPO
Get PDFProduksi bioplastik polyhydroxyalkanoates (PHA) oleh bakteri menghadapi masalah biaya produksi yang tinggi. Masalah yang sama juga terjadi pada produksi ramnolipid biosurfaktan. Strategi baru telah diusulkan untuk mengurangi biaya produksi PHA, yaitu sel pertama diarahkan untuk menghasilkan produk ekstraseluler yaitu ramnolipid, lalu sel tersebut digunakan kembali untuk menghasilkan produk intrasleluer, yaitu PHA. Penelitian ini dilakukan untuk mempelajari produksi poli-hidroksialkanoat (PHA) dan ramnolipid secara simultan dari sumber karbon yang relatif murah menggunakan teknik batch kultur. Dalam penelitian ini, produk samping industri biodiesel dari minyak sawit mentah (CPO) digunakan sebagai sumber karbon dan sebagai pembanding digunakan minyak sawit. Hasil penelitian menunjukkan bahwa penggunaan sumber karbon produk samping CPO menghasilkan konsentrasi maksimum ramnolipid dan PHA masing-masing 80 mg/l dan 0,15 mg/l, yang dicapai pada konsentrasi sumber karbon 25 g/l dan waktu kultivasi 24 jam
Pemanfaatan Zeolit Alam Teraktivasi untuk Adsorpsi Logam Krom (Cr3+)
No full textPertukaran ion antara Cr3+ dan H+ menggunakan zeolit sebagai penukar ion adalah salah satu metode untuk memurnikan air dari ion kromium. Zeolit adalah senyawa aluminosilikat tetrahedral dengan struktur ikatan 3-dimesi, memiliki pori bagian dalam, dan luas permukaan yang tinggi, karena itu dapat digunakan sebagai adsorben. Tujuan penelitian ini adalah untuk mengevaluasi pengaruh waktu kontak optimum, suhu, dan konsentrasi kromium terhadap kapasitas penyerapan. Tahap pertama adalah mencampur zeolit yang telah diaktifkan dengan larutan kromium (10 ppm kromium) dalam tangki berpengaduk pada 25oC. Selanjutnya larutan diambil setiap 60 menit hingga konsentrasi residu larutan kromium konstan. Proses adsorpsi dilangsungkan pada suhu berbeda yaitu: 25, 30, 35, 40, 45, dan 50 oC. Untuk uji adsorpsi isotermal, pada suhu dengan hasil penyerapan terbaik divariasikan konsentrasi kromiumnya yaitu: 10, 20, 40, 60, dan 100 ppm. Dosis adsorben yang digunakan adalah 3 gram adsorbent/200 mL larutan krommium dengan kecepatan pengaduk 240 rpm. Larutan kromium dideteksi dengan menggunakan Atomic Absorption Spectroscopy (AAS) atau Spektroskopi Serapan Atom. Waktu kontak optimum diperoleh 3 jam menggunakan zeolit yang diaktifkan dengan asam, diperoleh nilai adsorpsi optimum 99,275%. Proses adsorpsi berjalan secara eksoterm, memiliki ?Ho = -3.9574,6 J/mol dan ?So = -117.227 J/moloK. Model isotermal adsorpsi mengikuti isoterm Freundlich menurut persamaan Qe = 0,044463C1/2,5125, kapasitas penyerapan Kf = 0,044463 mmol/gram adsorben, dan intensitas adsorpsi n = 2,5125
Feasibility of In-Situ Aeration of Old Dumping Ground for Land Reclamation
Get PDFDumping grounds are characterized by the absence of engineering controls such as base liners and cover layer. Consequently, these dumping grounds present risks for surrounding resources such as soil, groundwater and air. The concern for groundwater contamination by leachate from tropical dumping grounds is heightened due to the greater amounts of rainfall and subsequent infiltration and percolation through the waste mass. The emergent demand for old dumping grounds reclamation drives the need to employ remediation technologies. Generally, in-situ aeration is a remediation method that promotes aerobic conditions in the later stage of dumping ground. It accelerates carbon transfer, reduces remaining organic load, and generally shortens the post closure period. However, high rainfall in tropical areas straitens this technique. For example, pollutants could be easily flushed out and more energy should be required to overcome hydrostatic pressure. Although heavy rainfall could supply sufficient water to the substrate and accelerate degradation of organic matter, it may inhibit aerobic activities due to limited air transfer. The waste characterization from Lorong Halus Dumping Ground (closed dumping ground in Singapore) showed that the waste materials were stabilized after 22 years closure. According to the Waste Acceptance Criteria set by European Communities Council, the waste materials could be classified as inert wastes. One interesting finding was that leachate layer detected was about of 5 - 8 meter depth, which entirely soaked the waste materials. Hence, the reclamation design and operation should be carefully adjusted according to these characters. Lorong Halus Dumping Ground case study can provide a guideline for other tropical closed landfills or dumping grounds
Pengaruh Konsentrasi Substrat Kulit Nanas dan Kecepatan Pengadukan terhadap Pertumbuhan Lactobacillus plantarum untuk Produksi Asam Laktat
Get PDFOne of the alternative utilization of pineapple peel waste is to convert them to lactate acid via fermentation. This research is aimed to obtain better understanding on the growth of lactate bacteria (Lactobacillus plantarum) by varying substrate concentration: 100 g/L - 600 g/L and stirring rate of 50 rpm, 150 rpm, and 250 rpm. The growth of anaeroic process was performed without pH controlling with initial pH of 5 and temperature of 28OC. Pineapple peel was used as the substrate after romoving water content using ammonium dihydrogen phosphate. Cell growth was analyzed by calculating the total of microorganism cell using hemocytometer. In order to determine lactate acid production, glucose concentration was analyzed using spectrophotometer. Nelson-Somogy method was employed in this analysis. Ethanol concentration was also analyzed by calculating the titration of acid lactate concentration. The optimum growth of Lactobacillus plantarum was found at 28oC, stirring rate of 150 rpm and substrate concentration of 500 g/L contributing to the total cell of 3,85.108, 1,13.109, and 4,00.108 for lag, exponential, and decrease phase respectively. Further analysis carried out based on stirring rate of 150 rpm and substrate concentration of 500 g/L resulted in the largest average concentration of lactate acid of 1.620% v/v with glucose consumption percentage of 51,76%.Keywords: pineapple peel, Lactobacillus plantarum, lactate aci
Leaching of Oil from Tuna Fish Liver by Using Solvent of Methyl-Ethyl Ketone
Get PDFResearch of oil leaching from Tuna Fish Liver has been carried out by extracting of tuna fish liver in soxhlet by using methyl-ethyl ketone as solvent. Liver of fresh tuna fish is blended, put into soxhlet, and extracted at temperatures of 60oC, 65oC, 70oC, 75oC, and 80oC. After obtaining the oil, separation between solvent and oil is carried out by distillation. Oil obtained is analyzed by testing the yield, acid number, Iodine value, viscosity, and its impurities content. Yield obtained is influenced by temperature and time of leaching. Both variables indicates that the higher the variables, the more fish liver oil obtained. Maximum yield obtained is 25.552% at operating condition of leaching temperature 80oC, and leaching duration of 5 hours
Studi Analisis Serbuk dengan Teknik Krim Silikon Menggunakan Plasma Tekanan Tinggi yang Diinduksi oleh Laser Nd: YAG
Get PDFLaser-Induced Breakdown Spectroscopy (LIBS) is a technique that used for quantitative elemental analysis of various samples in different forms. In this technique, a laser light is focused on the surface of sample yielding a plasma just above the sample surface that used for analytical source. Nowadays, rapid powder analysis in tiny amount (mg) has been carried out using plasma induced by high power laser of Nd:YAG (Neodymium-doped Yttrium Aluminium Garnet) at atmospheric pressure. However, powder analysis using high power laser is still difficult to be carried out due to blow of powder when irradiated laser beam focused on a powder sample. In general, the powder must be transformed into pellet form prior to analysis. Pellet sample requires a lot of powder and it takes time for preparation. In this study, we developed a technique of powder sample with its size about 30 m ( 5 mg) that mixed with silicon grease ( 5 mg) that act as a binder. The mixed sample then thinly painted on the metal plate as sub-target. The study showed that by employing sillicon grease technique, a semiquantitative analysis of several elements contain in coal, rock, and water can be conducted. Meanwhile heavy metal in soils is still not able to detect. This results showed that sillicon grease technique using Nd:YAG laser can be applied for rapid semi-quantitative analysis of powder samples available only in tiny amounts.Keywords: high pressured plasma, Nd:YAG laser, powder analysis, silicon grease techniqu
Penggunaan Microsoft Excel dalam Memprediksi Aliran Fluida dalam Packed Bed
Get PDFFlow distribution is often a problem in the operation of the packed bed reactor. The problem is often referred as flow maldistribution and formation of localized hot spot region. This research is generally aimed to predict fluid flow distribution in the packed bed containing porous media by finite difference method using the software MS. Excel. Model verification result shows conformity between analytic method and result of calculation. Simple study of the finite difference method using the software MS. Excel can describe the fluid velocity profile in a packed bed containing porous media. This profile is similar with experiment of Kufner and Hofmann (1990) and Stephenson and Stewart (1986). The simulation was performed to determine the effect of process variables on the fluid flow velocity profile. Particle diameter influences fluid flow velocity. Bulk porosity also influences fluid flow velocity at axis up to certain distance from wall of reactor. Keywords: finite difference method, flow distribution, packed bed reacto
Pengaruh Kondisi Operasi Alat Pengering Semprot Terhadap Kualitas Susu Bubuk Jagung
Get PDFDrying method is one of techniques used in food preservation. This method usually means reducing water content which is the best contiditon for microorganism growth. Higher water content also causes some enzyms needed for food decomposition cannot work well. This research aims to produce corn milk powder and to study some variables effecting on quality of corn milk powder. Hopefully the results can provide some information and produce good quality of corn milk powder. The drying process was carried out with batch process where the material was put into spray dryer and the process was allowed for the given period of time. Heat was added by direct contact to the material. The pressures of the chamber were 2, 4, 6 and 8 bars and the temperatures were 100, 150, 200 and 250oC. The best results of the research of protein, fat and water contents were 25.86 %, 18.34%, and 6.14%, recpectively.Keywords: atomizer pressure, cornmilk powder, spray dryer, temperatur