Judul: Arang Aktif Berbasis Kulit Buah Malapari (Pongamia pinnata) sebagai Adsorben dalam Penangan Limbah Batik
Abstrak: Vegetable oil production of malapari (Pongamia pinnata) fruit leaving unprocessed waste. The purpose of this study was to use malapari fruit peel as raw material for preparing activated charcoal, characterizing, and applying the best quality activated charcoal produced as adsorbent for dyes of batik industry waste water. Some samples treated through carbonization at temperature of 450 ℃ and continued activation with phosphoric acid 2% and physical activation at 750 ℃ with flow steam for 60 minutes resulted the best quality of activated charcoal with methylene blue adsorptivity of 120 mg/g. Leaching with HCl 10% was able to increase methylene blue adsorptivity up to 193 mg/g which meet SNI 06-3730- 1995 requrement with specific surface area and pore surface area of 715 m2/g and 138 μm2,respectively. Indigosol dye adsorption by the best quality charcoal followed the Freundlich isotherm. The activated charcoal was able to reduce intensity of the dye in the waste water and the chemical oxygen demand of 98.51% and 97.43%, respectively.
Keyword: Bogor Agricultural University (IPB), malapari, batik dye waste water, activated charcoal

Judul: Pemanfaatan Arang Aktif Tempurung Kelapa Sawit dan Tongkol Jagung sebagai Adsorben Logam Berat pada Limbah Batik
Abstrak: Heavy metals in wastewater of batik industry dumped into the environment can cause pollution and decrease the quality of waters. Using activated carbon as the adsorbent is one way to reduce the heavy metals level in the wastewater. In this study, the activated carbons were prepared from palm shell and corn cobs. The activation was done through 2 methods, i.e. chemical activation (KOH 30% immersion) and physical activation (steamed). The result showed that the best activated carbon was prepared using KOH 30% treatment, giving 10.7% moisture content, 14.6% volatile matter, 18.1% ash, 67.1%bound carbon, 20.9% benzene adsorption, 121.0 mg/g methylene blue adsorption, and 584.5 mg/g iodine adsorption. The optimum adsorption of heavy metal was obtained in 90 minutes contact time using 1.0 g adsorbent. The activated carbon originated from corncob with KOH 30% treatment was capable to reduce iron and copper up to 63.32% and 79.25%, respectively.
Keyword: palm oil shell, heavy metal, corn cob, activated carbon

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