Judul: Aplikasi teknik biofilter untuk penghilangan gas NH3 oleh bakteri Nitrosomonas sp dengan menggunakan bahan pengisi kompos, arang sekam, dan serasah di pabrik lateks pekat
Abstrak: Air pollution is one of the most importance factor should be well thought-out. Most of human activities release pollutans into atmosphere. Without waste disposal management, the development of industry could create serious environmental problem such as air pollutant. Gas emission causing bad odor is one of the impacts of latex industry discharging from ammonia (NH3). Ammonia can cause unpleasant circumstance, decreasing esthetics and diminishing human health.
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Judul: Penggunaan bahan pengisi tanah, kompos, arang sekam dan serasah dengan teknik biofilter untuk menghilangkan NH3 pada ruang produksi lateks pekat
Abstrak: Concentrated latex industry use concentrated liquid ammonia to stabilize latex, its emitted fugitive NH3 gas in high concentration. Ammonia is a odorous gas and easy to condense that cause exhalation problem and the oxidized ammonia (nitrit) is toxic and cause poisonous. This condition result to health problems for worker and local resident so a serious handling to treatment this air pollution is urgently needed. The objective of this research is to determine the best packing material composition to remove ammonia by using biofilter technique and to determine removal capacity of biofilters during operation. This research was conducted in three industrial scale biofilters using different packing materials. The first Biofilter packed with soil, charred chaff, peat leaf (2:l:l) and starter, the second biofilter used soil, charred chaK compost (1:1:2), and starter. The third biofilter used soil, charred chaff, compost and peat leaf and also given starter ( 1:1:0.5:0.5). The inlet and outlet of ammonia gas (NH3) concentration were measured for 55 days. The condition of packed materials were analyzed for water content, total of N, nitrate, ion ammonium, carbon and population of Nitrosomonas sp. and heterotroph bacteria every week, while pH was measured every three days.
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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