Judul: Imobilisasi Pediococcus acidilactici dan Staphylococcus warneri pada Elektroda Microbial Fuel Cell Limbah Pemindangan Ikan
Abstrak: Bahan organik berlebih pada limbah cair industri perikanan dapat dimanfaatkan menjadi sumber karbon bagi bakteri yang terdapat pada sistem microbial fuel cell (MFC). Pediococcus acidilactici (A1G) dan Staphylococcus warneri (A3T2) merupakan bakteri yang dapat ditemukan pada elektroda MFC. Penelitian ini bertujuan menentukan kinerja MFC yang lebih baik dalam menghasilkan elektrisitas antara penempelan bakteri pada katoda dan anoda serta menentukan perubahan beban polutan limbah cair pemindangan ikan. Penelitian ini dilakukan dalam lima tahap, yaitu kultivasi isolat bakteri, persiapan imobilisasi bakteri pada anoda dan katoda, persiapan desain alat MFC satu bejana, aklimatisasi lumpur aktif, dan proses transformasi MFC. Penempelan bakteri A1G pada anoda menghasilkan nilai elektrisitas MFC yang lebih tinggi dibandingkan dengan penempelan bakteri A3T2 pada katoda. Beban polutan setelah proses MFC mengalami penurunan pada parameter COD, BOD, dan TAN sebesar 50,65%, 35,07%, dan 60,08%. Nilai pH setelah proses MFC berkisar 6,03-6,33., The excessive organic components inside the fisheries wastewater could be utilized as a source of carbon for bacteria found in the microbial fuel cell (MFC) system. Pediococcus acidilactici (A1G) and Staphylococcus warneri (A3T2) are bacteria that could be found in the MFC electrode. The aim of this research was to decide which MFC functioned better in producing electricity between bacterial attachments on the cathode and the anode, as well as for deciding the pollutant load alteration of boiled fish processing wastewater. This research was carried out in five stages, bacterial isolate cultivation, preparation of bacterial immobilization at the anode and cathode, design preparation of single chamber MFC, acclimatization of activated sludge, and the MFC transformation process. The attachment of the AIG bacteria on the anode produced a higher MFC electrical value compared to the A3T2 bacterial attachment on the cathode. The pollutant load after the MFC process, based on the parameter of COD, BOD, and TAN decreased to 50,65%, 35,07%, and 60,08%. pH value after the MFC process was in the 6,03-6,33 range.
Keyword: elektrisitas, limbah cair, microbial fuel cell, penempelan bakteri

Judul: Imobilisasi Bacillus subtilis dengan Karaginan pada Anoda Microbial Fuel Cell Menggunakan Limbah Pemindangan Ikan
Abstrak: Limbah cair perikanan merupakan jenis limbah yang dapat menimbulkan pencemaran lingkungan. Pengolahan limbah cair perikanan dapat dilakukan melalui microbial fuel cell (MFC) untuk menghasilkan energi listrik dengan memanfaatkan mikroorganisme. Bacillus subtilis termasuk bakteri yang dapat menguraikan bahan organik dan mentransfer elektron untuk menghasilkan listrik. Penelitian ini bertujuan menentukan konsentrasi karaginan (0%, 1%, 1.5%, dan 2%) di anoda terhadap energi listrik dan beban polutan limbah cair ikan pindang setelah lima hari proses MFC. Biofilm bakteri yang terbentuk pada anoda setelah proses MFC mengalami peningkatan dan tertinggi pada konsentrasi karaginan 2% sebesar 6.3x10 cfu/cm2. Nilai tegangan listrik yang dihasilkan mengalami fluktuasi dan tertinggi sebesar 0.39±0.05aV pada karaginan 1%. Nilai chemichal oxygen demand (COD) dan biochemichal oxygen demand (BOD) limbah cair ikan pindang setelah MFC megalami penurunan sebesar 81.41% dan 60.02% pada karaginan 1.5%. Nilai pH pada limbah setelah proses MFC berkisar 7.11-7.33. Nilai total amonia nitrogen (TAN) mengalami peningkatan pada semua perlakuan dan tertinggi pada karaginan 0% sebesar 0.689±0.1 mg/L.
Keyword: energi listrik, limbah cair perikanan, microbial fuel cell

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