Judul: Produksi Bioflokulan dari Lumpur Aktif Industri untuk Air Sungai dan Air Limbah Industri
Abstrak: Bioflocculant is a natural flocculant from secretion product of microorganism that is polysaccharide, protein, glycoprotein, and nucleic acid. Source of bioflocculant used in this study is activated sludge from soy sauce industry PT. XXX. This study aims to analyze produce bioflocculant from industrial activated sludge with the isolation microb method and polysaccharide synthesis using acid method. The isolation microb method revealed that there are potential isolates that could floculate the suspension of kaolin by more than 60% in ten minutes which is isolates CMC-1 (78.36%). Isolate CMC-1 is identified as cellulolytic bacteria. Bioflocculant production using acid to catch polysaccharide resulted in only 53.92% flocculation effectivity but it is lower cost, more quickly, and easy to apply in industry. The selected bioflocculant is then tested for water and wastewater treatment. Research results showed the bioflocculant flocculation effectivity of 43.49% for river water and of 29.93% for wastewater. Addition of coagulant with specific dose can help bioflocculant increase flocculating effectivity.
Keyword: Bogor Agricultural University (IPB), flocculating efectivity, bactery isolation, coagulant, bioflocculant

Judul: Composition and Activity Bioflocculant from Flavobacterium sp.
Abstrak: Synthetic flocculant has widely used in industrial application as a colloidal aggregation. The usage of flocculant has known to be risky on human health and environment sustainability because the characteristic: neurotoxic, strong carcinogen, and unbiodegradable by microbe. Therefore, bioflocculant can become one of solution to provide alternative flocculant synthetic. Bioflocculant from Flavobacterium sp. has proven give flocculation activities well, 71.23%, although its component has not identified yet. Each bioflocculant has different biochemistry component so it is need to make sure its type for more precise application. The objective of this research were to analyze biochemistry component of bioflocculant from Flavobacterium sp. which has been gotten from ethanol precipitation. The result of this research showed that bioflocculant from Flavobacterium sp. contained polysaccaharide (carbohydrate) and protein are 0.0800 mg/mL and 0.0566 mg/mL for medium 1; 0.2284 mg/mL and 0.5983 mg/mL for medium 2. The flocculation activities of bioflocculant cultur from medium 1 (glucose 1% and sucrose 1%) and from medium 2 (glucose 0.2% and starch 3%) were 66.34% and 51.18%, respectively. Meanwhile, the flocculation activities of ethanol precipitation was less than its culture, were 12.78% from medium 1 and 24.93% from medium 2.
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Judul: Persamaan Geodesik Black Hole dengan Metrik Kerr 4+1 Dimensi dalam Koordinat Waktu Kosmik
Abstrak: Persamaan geodesik black hole dengan metrik Kerr 4+1 dimensi dalam koordinat waktu kosmik merupakan interpretasi lain dari persamaan geodesik black hole dengan metrik Kerr 4+1 dimensi, dimana acuan waktu yang digunakan diubah dari koordinat waktu wajar (proper time) ke dalam koordinat waktu kosmik (cosmic time). Waktu kosmik merupakan koordinat waktu yang dimana pengamat bergerak mengikuti ekspansi dari alam semesta. Penelitian ini merekonstruksi persamaan geodesik black hole dengan metrik Kerr 4+1 dimensi yang telah ditemukan pada penelitian sebelumnya menjadi persamaan geodesik yang memiliki fungsi terhadap dimensi waktu (t). Hasil akhir dari transformasi persamaan dapat digunakan sebagai bahan studi pustaka untuk penelitian lebih lanjut mengenai persamaan geodesik black hole dalam koordinat waktu kosmik.
Keyword: Dimensi ekstra, Metrik Kerr, Persamaan geodesik, Waktu kosmik