The paper presents water uptake and tensile properties of epoxy filled with inorganic fillers having different reactivity to water, namely Portland cement, fly ash, and calcium carbonate (CaCO 3) particles. Portland cement and CaCO 3, respectively have the highest and the lowest water reactivity. The filler volume fraction was ranging from 0 to 25 %. The results showed that for the reactive filler, with the increase of volume fraction, the water uptake increased and behaved as non-Fickian, whereas for the less reactive filler, the water uptake decreased and behaved as pseudo-Fickian. In dry condition, with the increase of volume fraction, the elastic modulus and tensile strength increased and tended to decrease, respectively, regardless of the filler type. However, in wet condition, the positive effect of filler on the elastic modulus diminished due to excessive plasticization of the matrix, and the reduction of elastic modulus of the most reactive filler is the lowest.

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Keberlimpahan sampah styrofoam dapat diatasi dengan proses pengolahan yang tepat, salah satunya adalah dengan proses pirolisis. Penelitian sebelumnya melakukan pirolisis menggunakan katalis zeolit alam yang relatif mudah didapatkan namun menghasilkan banyak senyawa benzena dan toluena. Selain itu katalis Ni/Si juga telah digunakan, walaupun lebih baik daripada zeolit alam namun katalis ini harganya mahal, sehingga penelitian ini bertujuan untuk mengetahui jenis katalis yang harganya murah dan dapat menghasilkan produk minyak dengan senyawa benzena dan toluena yang relatif kecil akibat dari perengkahan. Penelitian ini dilakukan dengan pengecilan ukuran styrofoam, sebanyak 130 gr katalis dimasukan ke dalam reaktor pirolisis selama 120 menit, kemudian katalis silika ditambahkan ke dalam reaktor. Pada variabel berat katalis, percobaan dilakukan pada suhu 460 o C dengan variasi berat katalis 0, 13, 26, 39, 52, dan 65 gram. Untuk variabel suhu, percobaan dilakukan dengan berat katalis 26 gram dan variasi suhu 340, 380, 420, 460, 500, dan 540ºC. Dekomposisi sampel diuji dengan metode Thermogravimetri Analyzer (TGA). Pengujian karakteristik dan nilai kalor CHP juga dilakukan pada penelitian ini, dimana karakteristik senyawa cairan hasil pirolisis (CHP) dianalisis dengan Gas-Chromatography Mass Spectrometer, pengujian kalor terhadap CHP dengan calorimetric bomb. Yield cairan terbesar diperoleh dengan menggunakan berat katalis 26 gr pada suhu 500ºC yaitu 95,65%. CHP yang dihasilkan mengandung senyawa stirena, toluena, aldehid, isopropil benzena, diphenil, alkohol, dan alkana. Dari penelitian ini pirolisis styrofoam dengan katalis silika alumina dapat menghasilkan cairan jenis bahan bakar yang tergolong kategori solar jenis 51.

Textile industry waste contains dyes that are difficult to decompose naturally and cause disruption of ecosystems in water. The colorant that is often used in the textile industry is methylene blue which is a cationic heterocyclic aromatic compound. This compound is so stable that it is difficult to decompose naturally and is harmful to the environment in large concentrations. Therefore, we need a waste treatment technology that can reduce the concentration of dye waste in water. So far, the adsorption method remains the most efficient and effective technique in removing dyes because of its relatively large adsorption capacity. One method that can be used is the adsorption method using natural zeolite. Zeolite is one of the non-metal mineral commodities or multipurpose industrial minerals, one of which is as an adsorbent or adsorbent media. This study aims to determine the potential of natural zeolite in absorbing methylene blue with variations in the concentration of methylene blue and various sizes of natural zeolite mesh. The procedures in this experiment include, the preparation of natural zeolite with size variations of 20-60 mesh, 60-100 mesh and> 100 mesh and variations in the concentration of methylene blue used 15 ppm, 30 ppm and 45 ppm with contact time from 0 to 180 minutes. From the results of the study it was found that the smaller the size of natural zeolite used, the greater the percentage of dye removal that is at mesh size> 100 mesh the percentage of dye removal was 32.11%. As for the variation of the concentration of methylene blue, the smaller the concentration, the natural zeolite can work optimally ie at a concentration of 15 ppm at 180 minutes the remaining methylene blue concentration of 0.145 ppm.

The colorant that is often used in the textile industry is methylene blue which is a cationic heterocyclic aromatic compound. This compound is very stable and is difficult to decompose naturally leading to environment in large concentrations. Therefore, a waste treatment technology to reduce the concentration of dye waste in water becomes importannt. So far, adsorption method with activated carbon remains the most efficient and effective technique in removing dyes from liquid waste due to its relatively large adsorption capacity. Activated carbon is one of the non-metallic mineral commodities or multipurpose industrial minerals, one of which is as an adsorbent or adsorbent media. This study aims to determine the potential of activated carbon in adsorbing methylene blue with variations in the concentration of methylene blue and particle size of activated carbon. The procedures in this experiment include, the preparation of activated carbon with size variations (20-60, 60-100 and> 100 mesh) and variations in the concentration of methylene blue (15 ppm, 30 ppm and 45 ppm) with contact time (0 to 180 minutes). From the results of the study, it was found that the smaller the size of activated carbon used, the greater the adsorption capacity, ie at mesh size> 100 mesh, the adsorption capacity was 9.8%. Whereas, the smaller the concentration of methylene blue, the activated carbon could work optimally at a concentration of 15 ppm at 30 minutes with adsorption capacity as high as 100%.Keywords: adsorption; Methylene Blue; activated carbon; concentration; time; particle size

The poor degradability of plastics has led to huge plastics deposit in a landfill of which pyrolysis technology has been proposed to solve plastics waste problem. This paper reports the study on characteristics of two kinds of plastic wastes: selected packaging plastics and PVC. Characterizations have been performed for investigating water content, ash content, and decomposition temperature. The results revealed that the water content of packaging plastic waste was 0.69 ± 0.11%, while PVC was 1.22 ± 0.24%. The ash contents are 2.36 ± 1.03 % and 27.24±1.73 % for packaging plastics waste and PVC waste respectively. Plastic waste from packaging application and PVC waste decomposed at a temperature of 300-500°C and 200-800°C respectively. Decomposition of PVC waste took place in three stages: 200-370°C, 370-525°C and 600-800°C. It is recommended that the pyrolysis process should be conducted in the range of 300-500°C for packaging plastic waste and 200-800°C for PVC waste.

National energy demand has been fulfilled by non-renewable energy sources, such as natural gas, petroleum, coal and so on. However, non-renewable energy reserves deplete increasingly which can cause an energy crisis. Conversion of biomass into energy becomes one of the solutions to overcome it. Indonesia has an enormous biomass potential especially from sugarcane plantation. Sugarcane plantations produce waste of bagasse abundantly. Commonly bagasse is utilized as energy source by conventional combustion. This research studies the utilization of bagasse as energy source by gasification technology to produce gas fuel. The gasification model used in this research is downdraft gasifier equipped with cyclone to separate gas with solid or liquid gasification products. The result has shown that gasification of bagasse has produced flammable syngas. The increase of bagasse weight increases the amount of syngas of gasification process. Carbon monoxide is the greatest content of syngas, while a few amount of H2, CH4 are also detected. Bagasse through gasification process is very potential source of alternative energy, since it is derived from waste and a cheap material.

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