Judul: Penentuan konstanta kinetika reaksi denitrifikasi pada pengolahan limbah cair industri hasil perikanan dengan lumpur aktif
Abstrak: Limbah cair indushi hasil perikanan memiliki karakteristik dengan kandungan bahan organik khususnya nitrogen yang tinggi. Pada lingkungan perairan keberadaan nitrogen berlebih tersebut dapat menyebabkan turunnya oksigen terlarut, eutrofikasi, pendangkalan, penyebaran bau, keracunan ikan dan methemoglobinemia. Salah satu teknologi yang banyak dilakukan untuk mengurangi konsentrasi nitrat addah dengan pengolahan secara biologis menggunakan proses denitrifikasi. Prinsi~in i adalah memanfaatkan kegiatan mikroorga nisme dalam air untuk menguraikan dan memecahkan bahan-bahan organik yang terkandung dalam air limbah menjadi bentuk yang lebih sederhana.
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Judul: Kajian penurunan nitrogen amonia pada proses nitrifikasi dalam pengolahan limbah cair industri perikanan
Abstrak: Limbah cair Industri Pengolahan Hasil Perikanan memiliki karakteristik dengan kandungan bahan organik dan nutrien (nitrogen) yang tinggi. Pada lingkungan perairan keberadaan nitrogen berlebih tersebut dapat menyebabkan turunnya konsentrasi oksigen terlarut, eutrofikasi, pendangkalan, penyebaran bau, keracunan ikan dan methemoglobinemia. Penelitian ini bertujuan untuk mempelajari proses nitrifikasi, menentukan pengaruh Hidrolic Retention Time (HRT) terhadap efisiensi penyisihan nitrogen amonia dan menentukan kinetika parameter proses nitrifikasi pada pengolahan Limbah Cair Industri Pertanian. Penelitian dilaksanakan dengan menggunakan bioreaktor aerobik dan clarifier yang disusun dengan konfigurasi sinambung aerobik-clarifier. Limbah cair artifisial yang digunakan dibuat dengan perbandingan berat ikan (kg) dan volume air (liter) 1:5. Perlakuan yang dilakukan menggunakan 5 taraf perlakuan HRT, yaitu: 3; 2; 1; 0,5 dan 0,25 hari. Hasil pengamatan menunjukan, semakin lama waktu tinggal limbah dalam reaktor, semakin besar efisiensi penyisihan NH3-N dan TKN (Total Kjeldahl Nitrogen) yang dilakukan, dimana pada penelitian ini efisiensi penyisihan optimal NH3-N dan TKN dicapai pada HRT 3 hari. Nilai parameter kinetika untuk koefisien hasil mikroba terhadap NH3-N yang digunakan (YNH) = 44,4810 mg MLVSS/mg NH3, laju pertumbuhan spesifik maksimum bakteri (µm) = 10,0232 hari, konstanta setengah kecepatan konsentrasi substrat NH3-N (KNH) = 174,530 mg MLVSS/L NH3, dan koefisien penguraian sel (Kd) = 4,7389 hari¹.
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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