Undergraduate Theses
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/13
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Item Meiofaunal assemblages in the mangrove habitat in Taklong Island, Nueva Valencia, GuimarasBocoran, Mary Grace G. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1999-03)Meiofauna are metazoans that can pass through a sieve with a mesh of 0.5mm but retained in a mesh of 0.063mm sieve. These organism are interesting to benthic scientist due to its capacity to determine the extent of pollution in the area and its role in the food web of an ecosystem. This study aims (1) to come up with a list of meiofaunal species present in the mangrove substratum, (2) to determine its density and abundance, and (3) to describe the meiofaunal environment in terms of temperature, salinity , pH, and oxygen content. The study was conducted in the mangrove habitat in Taklong Island Guimaras in February 1997. Thirty core samples were collected with a modified PVC core ( diameter=2.0 cm, length=15cm) from 3 areas: seaward, middle, and landward portions of the mangrove. There were eight broad groupings of meiofauna considered: nematodes, copepods, malacostracans, polychaetes, gastrotrichs, kinorhynchs, sipunculids, and others (including forams). The nematodes, of which there were 2 species observed, were the most abundant and comprised 42.14%. The copepods had 3 species observed and comprised 31.05%, 2 species of polychaetes comprised 5.04%,2species of gastrotrychs comprised 3.86% and malacostracans were 6.66%, kinorhynchs were 3.26%, and sipunculids were 0.89%. Unidentified organism which included foraminiferans, were 8.01 %. Range of meiofaunal density (number of individuals per cm'3 ) in three transects were 0.0042-0.1549 in the seaward area,0.0085-0.0785 in the middle area and 0.0021-0.0679 in the landward area. The nematodes had the highest density, and the sipunculids had the lowest density from the seaward to the landward area.Item Photodegradation of methylene blue in aqueous media using TIO2 -based heterogeneous photocatalysts under natural lightBernido, Julidyn P. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)This study developed two heterogeneous TiO2-based photocatalysts: pure TiO2 and Fe-doped TiO2 (Fe-TiO2). Heterogeneous catalysts were prepared by coating TiO2 and Fe-TiO2 powder on glass beads. The photocatalytic activity of both heterogeneous photocatalysts were studied by photodegradation of methylene blue in aqueous solution under two pH conditions (6 and 9) and two ionic concentration conditions (0 and 38 ppt). The Fe-TiO2 powder contained minimal amount (2.245%) of Fe as expected. However, surface functionality and ultraviolet-visible (UV-Vis) profile of both TiO2 and Fe-TiO2 powder were very similar indicating that doping did not alter these properties. Between the two heterogeneous catalysts prepared, the amount of Fe-TiO2 catalyst coated on glass beads was lower compared to pure TiO2. The removal of methylene blue was significantly affected by ionic concentration which removal is higher at lower ionic concentration (0 ppt). Although it appeared that the removal of methylene blue was higher at pH 9, statistical analyses revealed that the effect was not significant. In addition, the removal of methylene blue by the two catalysts were significantly different. Heterogeneous photocatalyst based on pure TiO2 showed higher removal of methylene blue in all pH and ionic concentration. Moreover, no interactive effects between variables were observed. Lastly, the blank showed no significant difference on the removal of methylene blue with the heterogeneous photocatalysts which suggest that degradation by direct photolysis from sunlight could be the reason for this result.
