Judul: Penerapan biofilter untuk penghilangan NH3 dan H2S dengan menggunakan bakteri Nitrosomonas sp dan Thiobacillus sp di pabrik latek pekat
Abstrak: Karet merupakan salah satu komoditi hasil pertanian yang sangat besar. Jumlah produksi karet Indonesia pada tahun 2004 mencapai 1.851 juta ton yang terdiri dari perkebunan rakyat dan perkebunan besar. Karena jumlah produksi karet yang sangat besar, maka industri karet di Indonesia mengalami perkembangan seperti industri RSS (Ribbed smoked sheet), karet remah dan lateks pekat. Berkembangnya industri ini menghasilkan masalah baru yaitu pencemaran lingkungan. Salah satunya adalah pencemaran udara yang dihasilkan dari parik lateks pekat dimana lateks pekat ini membutuhkan amoniak yang cukup banyak dalam proses produksinya dan menghasilkan gas H2S dari limbah cair dan lump. Tujuan utama penelitian ini adalah untuk mengetahui kemampuan teknik biofilter dalam mengatasi permasalahan emisi gas yang dikeluarkan dari pabrik lateks pekat. Tujuan khususnya adalah menentukan kapasitas penyerapan emisi gas pada masing-masing biofilter dan menentukan campuran bahan pengisi tambahan terhadap kinerja biofilter berdasarkan kemampuan menghilangkan emisi gas amoniak dan hidrogen sulfida.
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Judul: Penghilangan Gas H2S dan NH3 dengan Teknik Biofilter pada Ruang Produksi Pabrik Karet PTPN VIII Cikumpay, Purwakarta
Abstrak: Karet alam (natural rubber) yang diperoleh dari tanaman Hevea Braziliensis merupakan salah satu komoditas ekspor unggulan Indonesia yang jumlahnya cukup besar. Perkembangan industri karet menyebabkan timbulnya emisi berupa amoniak (NH3) dan hidrogen sulfida (H2S) yang mengganggu kesehatan pekerja pabrik karet. Biofilter adalah teknologi pengendalian pencemaran udara dengan cara menumbuhkan mikroorganisme pada bahan pengisi sehingga terbentuk biofilm atau biolayer yang dapat mengurai bahan-bahan pencemar udara.
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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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