Judul: Isoterm Adsorpsi pada Filter Karbon Aktif dengan Pengaruh Model Multimedia Filter pada Recirculating Aquaculture System (RAS)
Abstrak: Teknik pengolahan air yang dapat digunakan untuk menghasilkan kualitas air yang baik bagi budidaya ikan koi salah satunya adalah dengan penerapan Recirculating Aquaculture System (RAS). Penelitian ini bertujuan untuk menganalisis kesesuaian adsorpsi dari multimedia filter dan karbon aktif yang digunakan dengan model isoterm adsorpsi. Penelitian dilakukan dengan mengukur konsentrasi parameter amonia, nitrit, TSS, alkalinitas, suhu, pH, dan DO pada kualitas air dengan menerapkan beberapa variasi pada ketebalan dan debit multimedia filter. Variasi debit yang digunakan antara lain 45 L/menit dan 22,5 L/menit, serta variasi ketebalan media zeolite yang digunakan antara lain 30 cm, 60 cm, dan 90 cm. Kemudian melakukan analisis isoterm adsorpsi dengan menggunakan model isoterm adsorpsi langmuir, freundlich, temkin, halsey, dan khan. Kualitas air influen dan efluen pada unit filter karbon aktif menunjukan penurunan konsentrasi amonia, nitrit, dan TSS. Dari beberapa variasi yang digunakan, variasi ke-5 (ketebalan zeolite 90 cm dan debi 45 L/menit) merupakan variasi yang terbaik. Model isoterm adsorpsi khan merupakan model yang paling sesuai dikarenakan memiliki tingkat kesesuaian regresi yang paling tinggi., One of the water treatment techniques that can be used to produce good water quality for koi fish farming is the application of the Recirculating Aquaculture System (RAS). This study aims to analyze the adsorption suitability of the multimedia filter and activated carbon used with the adsorption isotherm model. The research was conducted by measuring the concentration of ammonia, nitrite, TSS, alkalinity, temperature, pH, and DO parameters on water quality by applying several variations on the thickness and discharge of the multimedia filter. Variations in the discharge used included 45 L/min and 22.5 L/min, and variations in the thickness of the zeolite media used were 30 cm, 60 cm, and 90 cm. Then analyze the adsorption isotherm using the Langmuir, Freundlich, Temkin, Halsey, and Khan adsorption isotherm models. The quality of the influent and effluent water in the activated carbon filter unit showed a decrease in the concentration of ammonia, nitrite, and TSS. Of the several variations used, the fifth variation (zeolite thickness 90 cm and debi 45 L/min) is the best variation. Khan adsorption isotherm model is the most suitable model because it has the highest level of regression suitability.
Keyword: Budidaya, karbon aktif, RAS, variasi

Judul: Variation of Multimedia Filter Thickness on Processing Performance of Aquaculture Recirculation System for Ornamental Fish Cultivation
Abstrak: Limbah cair ini memiliki banyak unsur hara diantaranya kandungan bahan organik dan anorganik, logam, dan ammonia. Sehingga, membutuhkan penanganan khusus untuk dapat mereduksi kandungannya. Penelitian ini bertujuan menganalisis potensi reduksi pencemaran air limbah hasil budidaya ikan hias koi dengan variasi debit dan ketebalan Multimedia Filter (MMF). Adapun desain dalam penelitian adalah 6 kombinasi debit dan ketebalan MMF, yaitu variasi 1 debit 45 L/menit ketebalan 30 cm, variasi 2 debit 22,5 L/menit ketebalan 30 cm, variasi 3 debit debit 45 L/menit ketebalan 60 cm, variasi 4 debit 22,5 L/menit ketebalan 60 cm, variasi 4 debit 45 L/menit ketebalan 90 cm, dan variasi 4 debit 22,5 L/menit ketebalan 90 cm. Hasil menunjukan bahwa variasi 5 dapat mereduksi seluruh parameter sesuai dengan standar baku mutu. Hasil filtrasi MMF pada variasi lima dapat mereduksi parameter ammonia dan nitrit sebesar 99,85% dan 99,80%.
Keyword: Ammonia, multimedia filter, nano membrane, RAS, zeolite

Judul: Lejeuneaceae Subfamily Ptychanthoideae (Hepaticae) in  West Java
Abstrak: Subfamily Ptychanthoideae of the family Lejeuneaceae (Hepaticae) in West Java is still poorly known. Publications on this subfamily are out of dated and written in the 19th or early of 20th century. The last taxonomic treatment of Ptychanthoideae of West Java was in 1933, many species names have changed since then. Studies on Ptychanthoideae of West Java are urgently needed. Studies on the Ptychanthoideae were based on the specimens collected from West Java. A total number of 361 of specimens deposited in the Herbarium Bogoriense (BO), Herbarium Biotrop (BIOT), Gottingen Herbarium (GOET) and Bangi Herbarium (UKMB) were examined, those are old and several recent specimens collected in West Java. Recent collections were made from Telaga Warna, Ciater, Gunung Halimun Salak National Park, Cibodas Botanical Garden, Bodogol Education Center and Conservation (Gunung Gede Pangrango National Park), University of Indonesia Campus Depok, including several collections from Banten Province. Twenty four species of Lejeuneaceae subfamily Ptychanthoideae are known from West Java, belonging to 8 genera namely Acrolejeunea (Spruce) Schiffn. (2 species), Archilejeunea (Spruce) Schiffn. (1 species), Lopholejeunea (Spruce) Schiffn. (10 species), Mastigolejeunea (Spruce) Schiffn. (3 species), Ptychanthus Nees (1 species), Schiffneriolejeunea Verd. (1 species), Spruceanthus Verd. (2 species) and Thysananthus Lindenb. (4 species). Two new records of Ptychanthoideae: Mastigolejeunea indica Steph. and Thysananthus minor Verdoorn are reported for Java. A determination key to the species is presented including their descriptions and illustrations.
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