Judul: Sintesis Nanokomposit Alofan/TiO2 dan Uji Fotodegradasi pada Zat Pewarna Biru Metilena
Abstrak: Industrial development has positive and negative impacts on the environment. The negative impact is environmental pollution by waste water containing dyes. Handling of this type of waste currently uses adsorption methods that give new problems, such as accumulation of environmentally hazardous adsorbents. This study applied a new concept of adsorption-photodegradation. This method was carried out by combining two materials into a nanocomposite, i.e. allophane and TiO2. Allophane is able to adsorb organic compounds, while TiO2 with ultraviolet light (UV), can degrade organic compounds. Allophane/TiO2 nanocomposite was prepared by mixing the constituents in its colloidal forms. The results showed that the adsorption capacity of the nanocomposite was greater than the capacity of allophane and TiO2 alone. The nanocomposite and allophane adsorption followed the Langmuir pattern. Photodegradation test on the nanocomposite irradiated with UV showed a new methylene blue wavelength on 573 nm, while controls that was carried out in dark room showed no shift in wavelength. Characterization using fourier transform infrared spectrometer showed a spectrum indicating the presence of allophane.
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Judul: Sintesis Nanokomposit Alofan/TiO2 dan Uji Fotodegradasi pada Zat Pewarna Biru Metilena
Abstrak: Perkembangan industri memberikan dampak positif dan dampak negatif bagi lingkungan. Salah satu dampak negatifnya adalah pencemaran lingkungan air oleh limbah zat warna. Penanganan limbah zat warna saat ini masih menggunakan metode adsorpsi yang justru menimbulkan masalah baru, yaitu terakumulasinya adsorben yang berbahaya di lingkungan. Penelitian ini menerapkan konsep baru, yaitu adsorpsi-fotodegradasi. Metode ini dilakukan dengan menggabungkan dua material menjadi nanokomposit, yaitu alofan dan TiO2. Alofan diketahui mampu mengadsorpsi dan TiO2 dengan bantuan sinar ultraviolet (UV) mampu mendegradasi senyawa organik. Nanokomposit alofan/TiO2 dibuat dengan mencampur dalam bentuk koloidnya. Hasil penelitian menunjukkan bahwa kapasitas adsorpsi nanokomposit alofan/TiO2 lebih besar daripada alofan dan TiO2 saja. Isoterm adsorpsi nanokomposit dan alofan mengikuti isoterm Langmuir. Dari hasil uji fotodegradasi biru metilena oleh nanokomposit yang disinari UV diperoleh puncak baru pada panjang gelombang 573 nm, sedangkan kontrol yang dilakukan di ruang gelap tidak memperlihatkan pergeseran panjang gelombang. Pencirian menggunakan spektrofotometer inframerah transformasi fourier menghasilkan spektrum yang khas untuk alofan.
Keyword: industrial development, adsorption methods, adsorption capacity

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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