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: Biodegradasi limbah minyak berat  (heavy oil waste / how) dengan teknik bioslurry menggunakan Salipiger sp. my7 dan Bacillus altitudinis my12
Abstrak: Bioremediation is the application of biological treatment to clean up of hazardous chemicals, included petroleum hydrocarbon such as heavy oil waste by using microorganisms. The final design must provide the controls to manipulate the environment for enhancing biodegradation of the target compounds. One of bioremediation techniques is bioslurry which has some advantages to degrade heavy oil waste. The experiment was conducted at laboratory scale and then continued to scale up phase using bacteria Salipiger sp. MY 7 and Bacillus altitudinis MY 12. Process of biodegradation was observed in 14 days for lab scale and 28 days for scale up. In lab scale, the best combination for bioslurry was using 15% TPH and 10% solid which has 80,16% of TPH degradation. The availability of microorganisms in bioslurry bioreactor was 4,1x107 -1,6x109 CFU/ml . Acidity (pH) of the slurry was in range of 6 – 7 which is normal condition for microorganisms to grow well, and with temperature in range of 31 – 34oC. The decreasing in TPH during the scale up phase (28 days) was from 18,82% to 11,93%. Biodegradation rate can achieved at 44,57 mg/L TPH/day at first week, and 37,57 mg/L/day at second week. Acidity (pH) was 7-9 and temperature was 28oC-30o C which is normal condition for microorganisms for doing biodegradation of heavy oil waste.
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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