Judul: Pengembangan model simulasi proses pengomposan sampah organik perkotaan dalam bioreaktor, Simulation model for composting of organic munificial solid waste in bioreactor
Abstrak: Municipal solid waste or MSW has a potency to be decomposed by microorganisms and transformed into compost. The waste contains 60%-75% of organic materials. The objective of this research was to optimize the composting F;ocess of MSW based on a simulation model. The specific objective were to developing the simulation model, validifying the model, analyzing the sensitivity of the model, and analyzing the quality of the compost. The growth of microorganisms, the rate of 0 2 consumption, the rate of C02 and H20 production, the rate of ratio carbon nitrogen or CM, and temperature were the variables tested in this research. Validation was carried out by comparing the result of simulation model with the experimental data of composting process. The sensitivity test was analyzed by comparing the changes of the dependent variables with the changes of independent variables.
Keyword: Municipal Solid Waste, Simulation model, Composting, Organic material, Bioreactor

Judul: Design and Evaluation of Reusable Materials-Based Aerobic Composter for Domestic Organic Waste Management
Abstrak: Limbah organik menjadi kontributor terbesar komposisi sampah di Indonesia pada tahun 2023. Untuk mengatasi hal ini, diperlukan sistem pengelolaan limbah organik skala domestik yang efisien, seperti composting. Penelitian ini bertujuan untuk merancang dan menguji komposter aerob dari barang bekas dengan variasi agen dekomposer: perlakuan larva BSF (P1 dan P2), perlakuan EM4 (P3 dan P4), dan kontrol (P5). Pencacahan limbah organik juga dilakukan pada P1 dan P3. Komposter P1 menunjukkan hasil terbaik dalam biokonversi limbah organik, dengan perubahan berat limbah dan kenaikan suhu paling signifikan serta emisi kebauan paling rendah. Perlakuan ini memiliki nilai reduksi (D) dan waste reduction index (WRI) tertinggi, yaitu 95.73% dan 3.19%/hari. Hasil pengujian kompos padat menunjukkan seluruh perlakuan memenuhi persyaratan yang ditetapkan pada Keputusan Menteri Pertanian Nomor 261 Tahun 2019. Hasil pengujian air lindi tidak memenuhi baku mutu yang dipersyaratkan pada setiap perlakuan, In 2023, Organic waste was the largest contributor to the composition of waste in Indonesia. To address this issue, an efficient domestic-scale organic waste management system, such as composting, is required. This study aims to design and test aerobic composters made from reusable materials with various decomposer agents: BSF larvae treatment (P1 and P2), EM4 treatment (P3 and P4), and control (P5). Shredding of organic waste was also done for P1 and P3. The P1 composter showed the best results in organic waste bioconversion, with the most significant changes in waste weight, the highest temperature increase, and the lowest odor emissions. This treatment had the highest reduction value (D) and waste reduction index (WRI), with 95.73% and 3.19%/day. The solid compost testing results showed that all treatments met the requirements set forth in the Keputusan Menteri Pertanian. The leachate test results did not meet the quality standards requirement
Keyword: performance testing, composter, design, decomposer, Organic waste

Judul: Identifikasi Molekuler Kompleks Spesies Himantura uarnak (Batoidea: Dasyatidae) di Indonesia.
Abstrak: Stingrays are one of the cartilaginous fish, apart of sharks and skates, and one of Indonesia's fishery resources. Almost of elasmobranch fishes are economically important fish. The refined products and live specimens of this fish are a lot of traded. Himantura uarnak, H. undulata and H. leoparda are stingray species in Himantura and Dasyatidae family, which are the most popular stingrays in Indonesia waters. The stingrays are major target species were used as a consumable product and trading products. Levels of species diversity of cartilaginous fish in Indonesia are very high, and also Indonesia is listed as one of the countries that use elasmobranch resources the highest in the world. Generally, this study aims to identify each species of H. uarnak species complex through molecular approaches. While specifically, this study aims to estimate the evolutionary process of species divergence and to determine the relationship between species. The methods were used in this study included field sampling, sample collection, and specimen identification, collection of genetic samples, analysis of genetic samples and data analysis . Size polymorphism nuclear DNA markers (intron EPIC) were used. Polymorphism alleles translated into genotypes and alleles frequency of five introns loci. The results of Bayesian analysis and Correspondence Analysis (CA) produced informative diagram of the population structure showed 4 different clusters. Cluster 1 and 4 were H. leoparda, Cluster 2 indicated as H. undulata and the Cluster 3 was H. uarnak. Cluster 1 was a variant of Cluster 4, in this time called as H. leoparda var.1. Separation of four clusters according to nuclear DNA need to be proved by mitochondria DNA maker by cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b). Molecular approaches were using mitochondrial DNA gene cytochrome c oxidase subunit I (COI) and cytochrome b produced 4 main groups (Group I, II, III and IV). Both of these molecular approaches showed each individual of groups were in consistent clade and the main group. Hence the H. uarnak species complex in Indonesian waters were divided into 4 main groups, and each was a particular species. The Group I and IV were the two group species that have been released as H. leoparda and Group I was H. leoparda var. 1 identified as cryptic species. Group II was one individual who grouped as H. undulata. Group III was one of other group that identified as H. uarnak and in accordance with the morphological characteristic through spotting pettern. Morphological approach to identified the stingrays of Himantura uarnak species complex clearly less accurate than the molecular approaches. Morphological approach should not be used to identify a species complex in stingrays without helped by other approaches.
Keyword: Himantura uarnak species complex, intron EPIC, cyt b, COI, spotting pattern