Judul: Skrining Bakteri Dekomposer Sebagai Penghilang Bau Kotoran Ayam
Abstrak: Proses dekomposisi ekskreta ayam menghasilkan gas-gas berbau penyebab polusi lingkungan. Salah satu teknik alternatif untuk mengurangi bau adalah dengan penggunaan bakteri spesifik. Tujuan dari penelitian ini adalah untuk mendapatkan isolat bakteri yang mampu mengurangi bau. Bakteri yang digunakan diisolasi dari kotoran ayam, guano, dan tanah gambut. Pemilihan isolat bakteri dilakukan dengan menggunakan media selektif. Semua isolat yang diperoleh diuji reaksi hipersensitif (HR) pada tembakau dan hemolisis (HL) pada agar darah. Bakteri yang menunjukkan respon HR dan HL negatif kemudian digunakan untuk percobaan lebih lanjut. Isolat tersebut diuji pada 100g ekskreta ayam. Lima isolat bakteri terpilih berdasarkan kemampuan mengurangi bau pada uji organoleptik adalah WiK 15, TnK 7, WiGu 11, CGu 7 dan MaGa 5. Gas NH3 dan H2S merupakan gas berbau yang diuji pada tahap selanjutnya. NH3 dan H2S dari dekomposisi ayam ekskreta dianalisis dengan metode spektrofotometri dan kolorimetri. Rata-rata produksi kumulatif NH3 dari tujuh hari pengamatan berkisar antara 1,09 ppm sampai 1,77 ppm, sedangkan total produksi kumulatif gas H2S berkisar antara 15,05 sampai 16,57 ppm. Isolat bakteri CGU 7 menunjukkan produksi NH3 terendah.
Keyword: chicken excreta, odorous gases, oxidizing bacteria

Judul: Utilization of Pumice Stone as a Bioreactor Media  to Reduce Environmental Odor Nuisance
Abstrak: Teknik biofiltrasi berfungsi untuk menghilangkan gas kebauan dengan menggunakan mikroorganisme. Pada penelitian ini, telah dilakukan biofiltrasi dengan media batu apung untuk menghilangkan bau yang berasal dari kotoran ayam dan sampah organik pasar. Penelitian bertujuan menganalisis kinerja media biofilter dan menganalisis perbedaan kinerja media biofilter untuk kedua sumber bau menggunakan metode panel dan pengukuran konsentrasi gas amonia (NH3) serta hidrogen sulfida (H2S). Pengujian biofilter dilakukan pada temperatur 25-30℃ dan kelembapan relatif 82-99% untuk sumber bau kotoran ayam dan temperatur 25-28 ℃ dan kelembapan relatif 93-99% untuk sumber bau sampah organik pasar. Efisiensi reduksi pada pengukuran konsentrasi gas dengan alat ukur konsentrasi NH3 dan H2S adalah 100%. Pada metode panel, kinerja biofilter untuk sumber bau kotoran ayam mencapai 100% untuk seluruh hari pengukuran. Namun, kinerja biofilter untuk sumber bau sampah organik pasar baru mencapai 100% pada hari ke-7. Skala hedonisme dan konsentrasi gas kebauan saling berkorelasi, yaitu semakin tinggi konsentrasi gas kebauan, maka semakin rendah nilai skala hedonisme. Hal ini ditunjukkan oleh nilai R2 sebesar 0,9., The biofiltration technique functions is to eliminate odorous gases by using microorganisms. In this research, biofiltration was carried out using pumice as a biofilter media to eliminate odor from chicken manure and organic market waste. The research aims to analyze the performance of biofilter media and analyze the differences between the biofilter performance to eliminate both odor sources using using panel method and measuring the concentration of ammonia gas (NH3) and hydrogen sulfide (H2S). Biofilter testing was carried out at a temperature of 25-30 ℃ and relative humidity of 82-99% for chicken manure odor and a temperature of 25-28 ℃ and relative humidity of 93-99% for organic market waste odor . The reduction efficiency in measuring gas concentrations method with NH3 and H2S concentration measuring instruments is 100%. In panel method, the performance of biofilter for chicken manure odor reached 100% for all measurement days. However, for market organic waste odor just reached 100% on the 7th day. The hedonism scale and odor gas concentration are correlated, the higher the odor gas concentration, the lower the hedonism scale value. This is indicated by the R2 value of 0.9.
Keyword: Biofilter, bioreactor media, environmental odor nuisance, pumice stone

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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