Judul: Arang Aktif Berbahan Baku sebagai Penyerap Polutan Gas dalam Media Kertas
Abstrak: Bamboo as a lignocellulosic material has a good prospects to be processed as an activated carbon due to its availability and low cost. The purpose of this study was to provide activated carbon from bamboo. The activation was done through 2 methods, i.e. chemical activation (KOH immersion) and physical activation (steamed). The quality indikator of the product was characterized by Indonesian National Standard (SNI 06-3730-1995) to be used as paper filler. In this experiment, the best activated carbon was the KOH treatment and steam as the activator at a temperature of 800 °C for 120 minutes. The characteristics include moisture content of 8.14%, volatile matter 9.08%, ash 16.45%, bound carbon 86.29%, benzene adsorption 14.36%, methylene blue adsorption 154.53 mg/g, and iodine adsorption of 240.213 mg/g. The best paper prepared by mixing the activated carbon was resulted from the ratio pulp of activated carbon, 2:1. The paper absorbed gaseous pollutans in a refrigerator namely 0.01%/cm2 para–hidroksibenzaldehida.
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Judul: Arang Aktif Berbahan Dasar Limbah Biomassa Kehutanan sebagai Penjerap Logam Cr, Pb, Cd, dan Pb dalam Limbah Cair Industri
Abstrak: Indonesia merupakan negara yang hampir setengah bagian dari wilayahnya merupakan hutan. Banyaknya wilayah hutan menghasilkan limbah biomassa oleh karena itu, perlu dilakukan pengolahan limbah biomassa sebagai arang aktif untuk menjerap logam berat limbah cair industri. Bahan yang digunakan adalah serbuk gergaji kayu dan limbah bambu yang banyak mengandung lignin dan selulosa. Proses pembuatan arang aktif terdiri atas dua tahap yaitu karbonisasi dan aktivasi. Penelitian ini bertujuan menentukan kondisi terbaik dalam pembuatan arang aktif dari bahan serbuk gergaji kayu jati dan limbah bambu sebagai penjerap logam berat limbah cair industri. Hasil karakterisasi menunjukkan bahwa arang aktif dari serbuk gergaji kayu dan limbah bambu dengan proses karbonisasi pada suhu 350−800 ℃ dan menggunakan aktivasi fisika, kimia, atau keduanya yang telah memenuhi persyaratan SNI 06-3730-1995. Arang aktif dapat menjerap logam berat seperti Cr, Pb, Cd, Hg cukup tinggi dalam limbah cair industri. Arang aktif yang diaktivasi dengan asam diperkirakan memberikan penjerapan logam berat lebih tinggi jika dibandingkan dengan proses aktivasi lainnya. Kata kunci: adsorpsi, arang aktif, limbah biomassa kehutanan, logam berat, Indonesia is a country where almost half of its territory is forest. Many forest areas produce abundant biomass waste. Therefore, it is necessary to process forest biomass waste as activated charcoal to absorb heavy metals from liquid industrial waste. The materials used in this study are wood sawdust and bamboo waste which contain a lot of lignin and cellulose. Activated charcoal production consists of two stages, namely carbonization and activation. This study aims to determine the best conditions in the manufacture of activated charcoal from teak wood sawdust and bamboo waste as heavy metal sorbents for industrial wastewater. The results showed that activated charcoal from wood sawdust and bamboo waste by carbonization process at a temperature of 350−800 and using physical, chemical, or both activations had met the requirements of SNI 06-3730-1995. Activated charcoal can adsorb heavy metals such as Cr, Pb, Cd, Hg which is relatively high in liquid industrial waste. Activated charcoal with acid is estimated to provide higher heavy metal adsorption when compared to other activation processes. Keywords: activated charcoal, adsorption, forestry biomass waste, heavy metals
Keyword: activated charcoal, adsorption, forestry biomass waste, heavy metals

Judul: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
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