Judul: Desain Instalasi Pengolahan Air Limbah Industri Tapioka Di CV. Tani Sadulur Bogor.
Abstrak: Pengolahan Limbah cair industri tapioka perlu dilakukan karena dapat merusak lingkungan yang disebabkan oleh kandungan bahan organik dan padatan terlarut yang tinggi. Tujuan penelitian ini adalah mengidentifikasi karakteristik limbah cair dan merencanakan desain instalasi pengolahan air limbah di CV. Tani Sadulur. Tahapan penelitian ini terdiri dari survei lapangan, pengumpulan data primer (volume dan debit limbah), identifikasi karakteristik limbah cair, penentuan perancangan desain dan perhitungan desain IPAL. Hasil uji limbah menunjukkan nilai BOD5 sebesar 156 mg/L, COD 537 mg/L, TSS 2209 mg/L dan pH sebesar 3,67. Debit limbah yang dihasilkan oleh CV. Tani Sadulur sebesar 7,5 m3/hari. Desain IPAL yang dibuat terdiri dari proses netralisasi, aerasi dan pengendapan pada unit sequencing batch reactor dan unit sludge drying bed. Hasil effluent berdasarkan penurunan BOD5 dan TSS setiap unit pengolahan adalah BOD5 19 mg/L, dan TSS 77 mg/L.
Keyword: Tapioca wastewater, WWTP

Judul: Rancangan Instalasi Pengolahan Air limbah Industri dengan proses biologis Biological nutrient removal
Abstrak: Kegiatan industri yang menghasilkan limbah cair, berpotensi menimbulkan pencemaran air di lingkungan apabila tidak diolah dengan sesuai. Penelitian ini bertujuan menganalisis dan mengidentifikasi karakteristik limbah cair PT. W, membuat rancangan unit IPAL yang sesuai, serta menganalisis efektivitas penggunaan mikroba pada pengolahan biologis biological nutrient removal. Metode pengujian serta baku mutu yang digunakan adalah SNI pengujian air limbah, Peraturan Menteri Negara Lingkungan Hidup Nomor 03 Tahun 2010, dan Keputusan Gubernur DKI Jakarta No. 582 Tahun 2005. Hasil analisis menunjukkan bahwa nilai Total Suspended Solids (TSS), amonia (NH3), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Sulfida (S), minyak dan lemak serta fecal coliform melampaui baku mutu sehingga perlu diolah lebih lanjut. Rancangan unit IPAL yang digunakan adalah bak ekualisasi, bak penampung, bar screen, grit chamber, sedimentasi primer, biological nutrient removal, clarifier, desinfeksi, sludge thickener, sludge digester, dan sludge drying bed. Biological nutrient removal merupakan unit pengolahan biologis suspended growth yang dipilih karena unit dapat dirancang untuk menurunkan nilai BOD, TSS, dan NH3 menjadi 10 mg/l, 10 mg/l, dan 1 mg/l. Tingkat efektivitas penggunaan mikroorganisme dalam unit ini dapat diketahui dari persen penurunan nilai parameter pencemar., Industrial activities that produces waste water, causes water pollution if it not treated properly. The research objectives were to analyze and identify PT. W wastewater characteristic, to design an appropriate WWTP of PT. W and analyze the effectiveness of microorganism at biological process biological nutrient removal. The method used was based on SNI of wastewater analyzing, Regulation of Minister of the Environment Number 03/2010, and DKI Jakarta‘s Governor Regulation Number 582/2005. Result of the analysis showed TSS, NH3, S, BOD, COD, oil and grease, and fecal coliform exceeded the threshold. The units that used are equalization tank, bar screen, grit chamber, primary sedimentation, biological nutrient removal (BNR), clarifier, disinfection, sludge thickener, sludge digester, and sludge drying bed. Biological nutrient removal is suspended growth biological process were chosen because it could remove BOD, TSS, and NH3 concentration into 10 mg/l, 10 mg/l, and 1 mg/l. The effectivity of microorganism uses can be known by percent removal of indicator concentrations.
Keyword: air limbah, biological nutrient removal, IPAL

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model