Judul: Kinerja Komposit Karbon Aktif-Magnetit sebagai Adsorben Ion Cr(VI).
Abstrak: Komposit karbon aktif-magnetit merupakan adsorben yang dapat digunakan untuk menjerap ion kromium heksavalen. Penelitian ini bertujuan menyintesis komposit karbon aktif-magnetit (KA-Fe3O4), menguji kinerjanya dalam menjerap ion Cr(VI), serta menentukan model adsorpsinya. Komposit karbon aktif-magnetit disintesis dengan metode hidrotermal dan dicirikan dengan spektroskopi inframerah. Parameter uji pada penentuan kondisi optimum adsorpsi berupa konsentrasi awal, pH larutan, dan waktu kontak. Kondisi optimum adsorpsi kedua adsorben diperoleh pada konsentrasi awal 350 mg L-1, pH larutan 3, dan waktu kontak 5 jam. Kapasitas adsorpsi karbon aktif dan karbon aktif-magnetit masingmasing 3.32 dan 3.30 mg g-1. Tambahan magnetit pada komposit karbon aktifmagnetit tidak menunjukkan perbedaan yang nyata dibandingkan dengan adsorben karbon aktif. Komposit karbon aktif-magnetit mengikuti model isoterm Langmuir.
Keyword: adsorpsi, karbon aktif, komposit, kromium, magnetit

Judul: Komposit Oksida Besi Magnetit-Zeolit Cikembar Sebagai Adsorben Cr(III) dan Cr(VI)
Abstrak: Iron oxide and iron oxide-zeolite magnetite composites have been prepared by co-precipitation method at temperature 70 ˚C. The magnetite composite were prepared with ratios of 1:1, 1:2, and 1:3 by weight. The magnetite composites were made to obtain an adsorbent that can be responsive to magnetic field so that it can be separated by simple magnetic procedure. The result from X-ray diffraction characterization showed a similarity of diffraction peak of zeolite with specific peak in PCDFWIN program database no 29-1257, which was mordenit. In addition, iron oxide and magnetite composites had a same peak with specific peak in PCDFWIN program database no 19-0629, which was iron oxide of magnetite (Fe3O4). Characterization using scanning electron microscope showed microstructure of zeolite that have small pores, while magnetite composite revealed iron oxide particles that cover and surrounded the pores of the zeolite. Adsorption experiment using surface response method showed that adsorption capacity of Cr(III) and Cr(VI) with composite did not increase significantly. However, the composite samples were capable in separating the composite adsorbent from the adsorbate medium using permanent magnet. The optimum capacity of adsorption occurred in 0.5 g of adsorbent, adsorption time of 12 hours, and initial concentration of 60 ppm
Keyword: 

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.
Keyword: