Judul: Penerapan Teknik Biofilter Skala Pilot pada Penghilangan Gas Penyebab Bau dari Gudang Penyimpanan Leum Industri Karet (Ribbed Smoked Sheet)
Abstrak: Emisi gas penyebab bau banyak ditimbulkan oleh industri, salah satunya adalah industri karet RSS. Efek yang ditimbulkan oleh gas tersebut meliputi berbagai segi antara lain mengganggu kenyamanan, masalah estetika serta munculnya masalah terhadap kesehatan manusia. Salah satu sumber emisi gas penyebab bau pada industri karet berasal dari gudang penyimpanan leum. Penelitian ini bertujuan untuk mengetahui kemampuan biofilter dalam mengatasi permasalahan emisi gas penyebab bau yang terdapat pada gudang leum industri karet, untuk menentukan kapasitas penghilangan emisi gas penyebab bau serta menentukan campuran bahan pengisi tambahan terhadap kinerja biofilter. Percobaan dilakukan menggunakan skala pilot dengan bahan pengisinya adalah kompos dan tanah, serta bahan tambahan (sekam, potongan daun karet dan chip kulit kayu karet) dengan perbandingan 4 : 2 : 1. Selain itu dilakukan penambahan dan tanpa penambahan sludge ke dalam biofilter. Parameter yang diukur adalah gas amonia (NH3) dan gas hidrogen sulfida (H2S). Kondisi media yang diukur meliputi pH, temperatur, kadar air, total N, S, C, nitrat dan mikroba. Analisis data menggunakan Metode Deskriptif dengan grafik yang akan menggambarkan kondisi seluruh parameter selama penelitian dilaksanakan. Selanjutnya penentuan bahan pengisi terbaik dengan menggunakan pembobotan atau scoring. Berdasarkan identifikasi terhadap emisi gas pada gudang penyimpanan leum maka didominasi oleh gas amonia (NH3) dan hidrogen sulfida (H2S), selain itu juga terukur gas CO, SOx dan NOx. Konsentrasi inlet gas amonia berada pada kisaran 12 – 100 ppm dan outletnya pada kisaran 1 – 6 ppm. Sedangkan untuk konsentrasi inlet gas hidrogen sulfida pada kisaran 0,045 – 0,402 ppm dan outletnya adalah 0,002 – 0,011 ppm. Efesiensi biofilter mampu dipertahankan hingga 95% selama 33 hari. Kemampuan biofilter dengan penambahan sludge menunjukkan kapasitas penghilangan 1,2 x 10-7 - 6,1 x 10-8 g-N/sel/hr dan 1,4 x 10-8 - 9,5 x 10-9 g-S/sel/hr dibandingkan dengan tanpa penambahan sludge menunjukkan kapasitas penghilangan 8,6 x 10-8 - 8,8 x 10-8 g-N/sel/hr dan 1,3 x 10-8 g-S/sel/hr. Berdasarkan scoring yang dilakukan untuk menentukan bahan pengisi terbaik maka diperoleh biofilter dengan bahan pengisi tambahan sekam dan penambahan sludge mempunyai kemampuan terbaik dalam penghilangan N, S dan penurunan permukaan terendah dibandingkan bahan pengisi tambahan yang lain.
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Judul: Penghilangan Polutan Gas Amoniak Dengan Biofilter Skala Pilot. Studi Kasus : PTPN VIII Pabrik Karet Cikumpay, Purwakarta, Jawa Barat.
Abstrak: Ammonia gaseous has a great potential to be a pollutant in rubber processing industries. The largest source of pollutant is at condensed latex processing. Therefore, biofilter was applied to remove emission of ammonia gaseous from the process. The objectives of this research were (1) to determine the level of physical and chemical absorption to ammonia sourness in forest soil based packing-bed material mixed with compost and carbonized rice husk, and (2) to determine the performance of biofilter to remove ammonia gaseous at pilot scale. Packing bed materials used were forest soil, bokashi compost and carbonized rice husk. The treatment of K111 was packed with forest soil, bokashi compost and carbonized rice husk with composised by 1:1:1. K112 was 1:1:2, K121 was 1:2:1, and K122 was 1:2:2. Physical and chemical characteristics of packing-bed materials within 5 parameters were obtained at ranked level of K112>K122>K111>K121. Carbonized rice husk influenced on physical - chemical characteristics of packing-bed materials, such as density, total porosity, water filled pore space and maximum capacity of loading, except air filled pore space. Those compositions were applied as packing bed materials to biofilters. Composition treatment of K111, K112, K121, K122 were applied to packing bed materials of B111, B112, B121 and B122. Biofilter were applied on pilot scale with 250 liters volume. For 55 days operation, ammonia pollutant concentrations were fluctuated from 0.18 to 68.66 ppm. Parameters inlet and outlet ammonia concentration, physical and chemical characteristics, population of ammonia oxidation bacteria and biofiltration process were monitored. Maximum removal capacities of B111, B112, B121 and B122 biofilters were 0.97, 1.46, 1.03 and 1.62 g-N/kg dry media. The result of biofiltration performance for 11 parameters showed that B112>B122>B121>B111. The best biofilter was determined by its ability in removing pollutant and the cost of required packing-bed. The price of packing bed materials from the lower prices were B111<B112<B122<B121. The cheapest price of packing bed material was B111, but it wasn’t a good performance of biofiltration. Therefore, B112 which was filled by forest soil, bokashi compost and carbonized rice husk with composition 1:1:2 was the best biofilter performance among them.
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Judul: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite