Judul: Produksi Gas Selama Proses Biodegradasi Heavy Oil Waste dengan Teknik Landfarming
Abstrak: Bioremediation is defined as biological degradation process of organic or inorganic wastes in a controlled condition to control and reduce their amount in the environment. In this study, the soil which had been poluted by heavy petroleum oil fractions, i.e. heavy oil waste (HOW), was used as sample. The bioremediation technique used in this study is an ex-situ technique. This study was conducted to determine the amount of produced gases during the HOW degaradation process. The highest CO2 production mean was obtained from the bioaugmentation treatment with compost adding, i.e. 244,5 mg/m3. This treatment also produced the highest NO2 production mean of 58,1 μg/m3. While the highest NH3 production was observed in pure HOW bioaugmentation treatment (155,6 μg/m3), and H2S was produced in the highest amount in pure HOW biostimulation treatment (3337,2 μg/m3). The SO2 gas production was not obvious in all treatments. Generally, all graphs of each gas production followed a similar sinusoidal pattern. From these results it can be infered that the degradation process of HOW happened during the treatments.
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Judul: Kemampuan Konsorsium Mikrob dari Kotoran Sapi dan Kuda pada Proses Biodegradasi Limbah Minyak Berat
Abstrak: Heavy oil waste (HOW) which is produced by petroleum industry has become environment problem until now. Bioremediation is a method that can recover the polluted environment. This research was carried out to evaluate microbe consortium from cow and horse manure in biodegradation of heavy oil waste with adjustment of total petroleum hydrocarbon (TPH) 5% (w/v) and 10% (w/v). The observed parameters were solid TPH, liquid TPH, total plate count, chemical oxygen demand, and pH. The highest percent degradation was obtained from 5% TPH. Microbes were easier in degrading 5% TPH than that of 10% TPH. This is because the low toxicity of TPH 5%. TPH degradation at the 21st day reached 40.36% with addition of horse manure consortium enriched by 5% TPH, while with cow manure consortium was only reached 22.77%. TPH degradation at the 21st day was reached with addition of horse manure consortium enriched by 10% TPH, while with cow manure consortium was reached 16.80% of TPH degradation. It also showed that microbes in consortium of cow’s manure were better on degrading HOW than microbes in horse manure consortium.
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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