Judul: Optimisasi Adsorpsi Biru Metilena oleh Alofan dan Nanokomposit Alofan-TiO2 serta Uji Fotokatalisisnya
Abstrak: Allophane is a natural clay mineral with high adsorption capacity. This mineral often found in volcanic soil. Indonesia is one of the countries with many active volcanoes, so the probability to find the type of mineral is quite high. To improve their characteristics, allophane was made into nanocomposite with TiO2, the resulting a substance with adsoptive-photocatalyst characteristics. In this research, the adsorption of methylene blue was optimized based on two parameters, agitation time and mass of the adsorbent. The optimazed agitation time for the adsorption of methylene blue by allophane and nanocomposite allophane-TiO2 were obtained at 1.5 hours. The optimized mass of allophane and nanocomposite were 80 mg and 60 mg respectively. The synthesized-nanocomposite was shown to have the adsorptive-photocatalytic properties because it can degraded methylene blue after irradiated with ultraviolet light.
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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: 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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