Judul: Development of Bioremediation Technology by Slurry Bioreactor for Diesel Oil Contaminated Soil
Abstrak: The development of bioremediation technology by slurry bioreactor is utilized for degradating of diesel oil waste since the slurry bioreactor has several advantages compare to the landfarming method. The purposes of the research were (1) To determine the optimum condition of diesel oil bioremediation process in slurry phase by treatment of contaminated level in soil and total solid at laboratory scale (2) To scale up the bioremediation process obtained from the previous stage. The research was conducted by implementing two treatments namely total solid (10, 15, and 40%) and diesel oil contaminated level in soil (5, 10, and 15%). The consortium of bacteria applied were Pseudomonas pseudomallei (PP), Enterobacter agglomerans (EA), and the consortium of bacteria derived from manure. The respons of diesel oil degradation observed by the Respons Surface Method (RSM). Slurry bioreactor were used to treat a contaminated soil by diesel oil and results showed total solid, contaminated level in soil, and both interaction were influenced positively towards the bacterial growth and were decreased in Total Petroleum Hydrocarbon/TPH. Laboratory scale were run first used small slurry bioreactor (500 ml) showed that hydrocarbon levels in the contaminated soil by diesel oil were reduced an optimum level up to 85.29% in the combination of 9.09% contaminated level in soil and 32.62% total solid treatment. The optimum condition in laboratory scale was applied for the scale up experiment (16 liter) showed that enhancement of consortium of PPEA bacteria and the consortium of bacteria derived from manure can be reduced hydrocarbon up to 91.6% (from 13964 ppm to 1167 ppm) after 20 days.
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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: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf