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Abstrak :
Teknologi Bioremediasi merupakan teknologi yang belakangan ini digunakan sebagai cara alternatif penanggulangan limbah hidrokarbon . Metode ini menggunakan mikroorganisme bakteri pemecah minyak seperti Pseudomonas aeruginosa untuk mendegradasi senyawa hidrokarbon sehingga dapat memulihkan lingkungan, tanah dan air yang tercemar. Penelitian pengujian ketahanan dan bakteri Pseudomonas aeruginosa ini merupakan bagian dari penelitian Tim Bioremediasi yang dilakukan di Departemen Teknik Gas dan Petrokimia. Penelitian ini dilakukan dengan menggunakan limbah buatan, yang merupakan campuran isooktan dalam air dan bakteri Pseudomonas aeruginosa dalam kultur medium Nutrien Broth (NB) dengan menggunakan teknik pengguncangan. Proses tersebut berlangsung pada kondisi temperatur 35"C, kecepatan shaker 30 rpm dan tekanan 1 aim dengan variasi konsentrasi substrat iso-oktana yang digunakan pada rentang 800 -10000 ppm volum. Secara umum hasil yang diperoleh dalam penelitian ini menunjukkan bahwa semakin tinggi konsentrasi kontaminan, semakin berkurang jumlah massa sel akhir yang dihasilkan, sedang laju pertumbuhan spesifik sel Pseudomonas aeruginosa relalif sama. Pertumbuhan terbaik sel dicapai (rentang kontaminan 800 ppm - 10000 ppm) pada konsentrasi 800 ppm dengan jumlah massa sel akhir sebesar 0,007079 gr/dm . Model pendekatan secara empiris terhadap laju pertumbuhan sel pada penelitian ini mengikuti persamaan lerusalimsky.

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Bioremediation is an alternative way to overcome hydrocarbon waste to restore contaminated water and soil environment. Microorganism such as Pseudomonas aeruginosa had been used to degrade hydrocarbons compounds. This research is a part of a bioremediation research which was conducted in Gas and Petrochemical Engineering Department. This research was conducted in a nutrient broth (NB) culture medium with shaking technique. The experiment was carried out at 35"C, rotation of 30 rpm and 1 aim pressure with iso-octane concentration variation in the range of 800 - 10000 ppm volume. The results show that the higher contaminant concentration, the less cell mass production while the specific growth rate of Pseudomonas aeruginosa were at the relative same rate. The highest cell growth rate was obtained at 800 ppm with the number of final cell was 7.08 10 gr/L. The empiric model of specific growth rate of this research is lerusalimsky.

Abstrak :
ABSTRACT
The tobacco extract has larvicidal activity because it contains nicotine and some toxic compounds. The need to form tobacco extracts in nanoemulsion was due to its smaller particle size, larger surface area, and slow release of active compounds. This study aims to evaluate the effectiveness of tobacco extract nanoemulsion against Aedes aegypti larvae. Nanoemulsion tobacco extract is made by high energy method using ultrasonication with frequency 20 kHz for 45 minutes. The tobacco extract was mixed with Tween 20 surfactant with the ratios are 1:0.5, 1:1, and 1:3 (w/w). From the result, bioassay test of larvicidal nanoemulsion with LC50 was 823.74 ppm (F1:0.5), 702.07ppm (F1:1), and 578.48 ppm (F1:3), lower than LC50 of tobacco leaf extract without nanoemulsion 1022.97 ppm. The decrease in LC50 values was directly proportional to the decrease in particle size. The lowest LC50 values are obtained by the formula F1:3 with an average particle size of 631 nm. This study shows that even if the nanoemulsion was not achieved, the emulsion of tobacco extract is potential to control the Aedes aegypti mosquito larvae effectively, due to lower than 750 ppm LC50 for (F1:1 and F1:3, 24 hr).

Abstrak :
Bagas merupakan residu padat pada proses pengolahan tebu menjadi gula, yang sejauh ini masih belum banyak dimanfaatkan menjadi produk yang mempunyai nilai tambah (added value). Bagas yang termasuk biomassa mengandung lignoselulosa sangat dimungkinkan untuk dimanfaatkan menjadi sumber energi alternatif seperti bioetanol atau biogas. Dengan pemanfaatan sumber daya alam terbarukan dapat mengatasi krisis energi terutama sektor migas. Pada penelitian ini telah dilakukan konversi bagas menjadi etanol dengan menggunakan enzim xylanase. Perlakuan dengan enzim lainnya saat ini sedang dikerjakan di laboratorium kami mengingat hemisulosa juga mengandung polisakarida lainnya yang dapat didekomposisi oleh berbagai enzim. Hasil penelitian menunjukkan kandungan lignoselulosa pada bagas sebesar lebih kurang 52,7% selulosa, 20% hemiselulosa, dan 24,2% lignin. Hemiselulosa merupakan polisakarida yang dapat dihidrolisis oleh enzim xylanase dan kemudian akan difermentasikan oleh yeast S. cerevisiae menjadi etanol melalui proses Sakarifikasi dan Fermentasi Serentak (SSF). Beberapa parameter yang dianalisis pada penelitian ini antara lain kondisi pH (4, 4,5, dan 5), untuk meningkatkan kuantitas etanol dilakukan penambahan HCl berkonsentrasi rendah (0,5% dan 1% (v/v)) dan bagas dengan perlakuan jamur pelapuk putih (L. edodes) selama 4 minggu. Proses SSF dilakukan dengan waktu inkubasi selama 24, 48, 72, dan 96 jam. Perlakuan dengan pH 4, 4,5, dan 5 menghasilkan konsentrasi etanol tertinggi berturut-turut 2,357 g/L, 2,451 g/L, 2,709 g/L. Perlakuan penambahan HCl konsentrasi rendah mampu meningkatkan produksi etanol, penambahan dengan konsentrasi HCL 0,5 % dan 1 % berturut-turut menghasilkan etanol 2,967 g/L, 3,249 g/L. Perlakuan dengan menggunakan jamur pelapuk putih juga dapat meningkatkan produksi etanol yang dihasilkan. Setelah bagas diberi perlakuan L. edodes 4 minggu mampu menghasilkan etanol dengan hasil tertinggi 3,202 g/L.

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Utilization of Bagasse Cellulose for Ethanol Production through Simultaneous Saccharification and Fermentation by Xylanase. Bagasse is a solid residue from sugar cane process, which is not many use it for some product which have more added value. Bagasse, which is a lignosellulosic material, be able to be use for alternative energy resources like bioethanol or biogas. With renewable energy resources a crisis of energy in Republic of Indonesia could be solved, especially in oil and gas. This research has done the conversion of bagasse to bioethanol with xylanase enzyme. The result show that bagasse contains of 52,7% cellulose, 20% hemicelluloses, and 24,2% lignin. Xylanase enzyme and Saccharomyces cerevisiae was used to hydrolyse and fermentation in SSF process. Variation in this research use pH (4, 4,5, and 5), for increasing ethanol quantity, SSF process was done by added chloride acid (HCl) with concentration 0.5% and 1% (v/v) and also pre-treatment with white rot fungi such as Lentinus edodes (L.edodes) as long 4 weeks. The SSF process was done with 24, 48, 72, and 96 hour?s incubation time for fermentation. Variation of pH 4, 4,5, and 5 can produce ethanol with concentrations 2,357 g/L, 2,451 g/L, 2,709 g/L. The added chloride acid (HCl) with concentration 0.5% and 1% (v/v) and L. edodes can increase ethanol yield, The highest ethanol concentration with added chloride acid (HCl) concentration 0.5% and 1% consecutively is 2,967 g/L, 3,249 g/L. The highest ethanol concentration with pre-treatment by L. edodes is 3,202 g/L.

Abstrak :
Mikroalga Chlorella vulgaris Buitenzorg memiliki potensi dalam memfiksasi CO2 dan dilihat dari kandungan protein dan zat esensiil lainnya dapat dimanfaatkan sebagai bahan makanan tambahan. Perlakuan pencahayaan siklus harian pada kultivasi Chlorella vulgaris Buitenzorg menunjukkan hasil akhir produksi biomassa dan laju fiksasi CO2 yang lebih rendah dibandingkan dengan perlakuan pencahayaan sinambung, dengan perbandingan hasil produksi biomassa sebesar 79,0% serta nilai CTR (carbon dioxide transferred rate) sebesar 54,0% dan nilai qCO2 (microbial carbon dioxide fixation ability) sebesar 50,0% sebagai parameter yang menunjukkan kemampuan fiksasi CO2 -nya. Kedua perlakuan tersebut dilakukan dalam 1,0 L kolom gelembung mengandung 600 mL medium Beneck yang dihembuskan udara yang mengandung CO2 sebesar 10.0% dengan kecepatan superfisial hembusan udara sebesar 3,60 m/h pada temperatur 29,0oC dan tekanan operasi 1.0 atm. Sebagai tambahan, energi pembentukkan biomassa (EX) juga menunjukkan nilai 70,0% lebih besar dibandingkan perlakuan pencahayaan sinambung.

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Green Algae Chlorella vulgaris Buitenzorg green have a potencies such as their ability in CO2 fixation and it?s protein and essensial contents observation for supplement food purpose. Chlorella vulgaris Buitenzorg?s cultivation results using daily cycle illumination showed that the final biomass production and CO2 fixation rate are lower if compared to continuous illumination treatment. The comparisons between these two treatments are 54.0% for CTR (carbon dioxide transferred rate) value and 50.0% for q CO2 (microbial carbon dioxide fixation ability) value as parameter that shown it?s CO2 fixation ability and 79.0% for biomass production. Both of treatments was done in 1.0 L bubble column fotobioreactor content 600 mL Beneck medium that was sparged by 3.6 m/h superficial velocity of air consisting of 10.0% CO2 as carbon source at 29.0°C and 1.0 atm. Additionally, the consumption energy for biomass formation (EX) in daily cycle illumination, was 70.0% larger than con tinuous illumination treatment.

Abstrak :
Chlorella vulgaris Buitenzorg cultivation using three bubble column photo bioreactors arranged in series with a volume of 200 mL for 130 hours shows an increase of biomass production of Chlorella vulgaris Buitenzorg up to 1.20 times and a decrease of the ability of CO2 fixation compared to single reactor at a periodic sun illumination cycle. The operation conditions on cultivation are as following: T, 29.0oC; P,1 atm.; UG, 2.40 m/h; CO2, 10%; Benneck medium; and illumination source by Phillip Halogen Lamp 20W /12V/ 50Hz. Other research parameters such as microbial carbon dioxide transferred rate (qco2), CO2 transferred rate (CTR), energy consumption for cellular formation (Ex), and cultural bicarbonate species concentration [HCO3] also give better results on series of reactor.

Abstrak :
Triglyceride hydrolysis using lipase has been proposed as a novel method to produce raw materials in food and cosmetic industries such as diacylglycerol, monoacylglycerol, glycerol and fatty acid. In order to design a reactor for utilizing this reaction on industrial scale, constructing a kinetic model is important. Since the substrates are oil and water, the hydrolysis takes place at oil-water interface. Furthermore, the triglyceride has three ester bonds, so that the hydrolysis stepwise proceeds. Thus, the reaction mechanism is very complicated. The difference between the interfacial and bulk concentrations of the enzyme, substrates and products, and the interfacial enzymatic reaction mechanism should be considered in the model.

Abstrak :
The main focus of this article was to investigate the potential of natural zeolite adsorbent for the removal of CO2 and H2S in biogas produced from palm oil mill effluent (POME) in fixed-bed column adsorption. The effects of the flowrates and dosage of the adsorbent on the CO2 adsorption were also studied. The surface area of the adsorbent was determined using the Brunauer, Emmett, and Teller (BET) model, while the pore size distribution was calculated according to the Barrett, Joyner, and Halenda (BJH) model. The morphology of the adsorbent was determined by field emission scanning electron microscopy and energy dispersive x-ray (FESEM-EDX) analysis. Before and after purification, the biogas was analyzed by gas chromatography with a thermal conductivity detector and polydimethylsiloxane as a column. Biogas from the POME, via the anaerobic digestion process, produced 89% CH4 and 11% CO2. The surface and structure of the clinoptilolite zeolites was modified by a strong acid (1M HCl), strong base (1M NaOH), and calcination at 450°C, and the surface area of the natural zeolites was reduced up to 16%. The working capability of CO2 adsorption by the modified zeolites decreased with increasing flow rates (100, 200, and 300 mL/min) of the biogas, with levels of CO2 at 106,906, 112,237, and 115,256 mg/L. The removal of the CO2 in the biogas by using adsorbent dosages of 1.5, 2.0, and 2.5 g was 97,878, 97,404 and 93,855 mg/L, respectively. The optimum purification of the biogas occurred under the flow rate of 100 mL/min and adsorbent dosage of 2.5 g. The high working capability of the modified zeolites for the removal of CO2 in the biogas was a key factor, and the most important characteristic for the adsorbent. The results indicate that clinoptilolite zeolites are promising adsorbent materials for both the purification and upgrading of biogas.