Judul: Bioremediasi Tanah Terkontaminasi Minyak Bumi dengan Menggunakan Bacillus popilliae ICBB 7859 di PT. Caltex Pacific Indonesia
Abstrak: Oli spilis in large amount has becomes a hazardous polutant material in encironment. Bioremediation is a degradation process using organism has become an alternative approach in this centuries.
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Judul: Aplikasi Bakteri Lokal Indonesia dalam Bioremediasi Tanah Terkontaminasi Minyak Berat, Minyak Ringan dan Limbah Oli Bekas
Abstrak: Oil and gas industrial activity has a potency to contaminate soil. One of the waste released by oil and gas industry is oil sludge. Until now, oil sludge is still a major problem in oil and gas industry especially due to its huge amount. This research was aimed to study the effectiveness of Indonesian local bacteria in bioremediation of soil contaminated with heavy oil, light oil and used lubricant at bench scale. This research was begun by cultivation of 15 strains of hydrocarbon degrading bacteria in Luria Bertani (LB) medium. Each of the cultured isolate was left in a few minutes for thawing, then it was transfered to 20 ml LB medium in erlemeyer using ose. Then, the cultures were incubated in a shaker for 24 hour at ambient temperature. The 15 isolates were selected of their potency in degrading heavy oil by visual assay based on the changes in oil condition in the erlemeyer. The best three heavy oil degrading bacteria selected were Bacillus sp ICBB 7859, Bacillus sp. ICBB 9461 and Bacillus sp. ICBB 5071. The three selected isolates were further characterized by hypersensitive response test, growth curves characteristic, haemolysis test, and antagonistm test. In the main experiment, the three isolates were applicated to soil contaminated with heavy oil, light oil and used lubricant as a single or in combination culture. Parameters used to evaluate their effectiveness in the degradation were soil respiration, pH value, and TPH (Total Petroleum Hydrocarbon). The combination of the three isolates (Bacillus sp ICBB 7859, Bacillus sp. ICBB 9461, and Bacillus sp. ICBB 5071) was the most effective treatment for reducing TPH value of all tested materials (heavy oil, light oil and used lubricant) although statistically was not significantly different with other treatment at 5% test level. The TPH values of soil contaminated with heavy oil, light oil and used lubricant were respectively 0,40, 0,70, dan 0,41% at the end incubation period for 9, 6 and 4 weeks. Based on the GOI Environment Ministerial Decree No. 128/2003, the TPH value of the oil contaminated soil have to be reduced below 1%, before being used for other purposes. Although the combination of the three isolates was the best treatment, it can not be applied in the field due to the patogenicity of the two isolates (Bacillus sp. ICBB 9461 and Bacillus sp. ICBB 5071). Only one isolate, Bacillus sp. ICBB 7859, that has been proven as nonpathogenic one and, therefore, can be used for bioremediation of oil contaminated soil in the large scale.
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Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular