Undergraduate Theses
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Item The adsorption capacity of silica gel and rice hull ash on phenol and anilineBulatao, Ben Fermin P. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2011-04)Chemical waste has been a problem here in the University of the Philippines Visayas, Miagao, Iloilo. Various methods of removal have been utilized. Extraction of silica gel from rice hull and rice hull ash was used to remove organic compounds (phenol and aniline). In this study, silica gel and rice hull ash adsorption on phenol and aniline were investigated with varying contact time and initial concentration. Silica gel reaches its optimum adsorption of both phenol and aniline at 60 minutes contact time. Silica gel was the basis for rice hull ash’s contact time because rice hull ash is 90% by weight silica gel.. Silica gel-phenol system decreases it adsorption capacity as the initial concentration is increased from 25 ppm to 100 ppm. Rice hull ash- phenol system, on the other hand, shows that the adsorption capacity increases as the initial concentration is increased. Both on silica gel-aniline system and rice hull ash- aniline system have increasing adsorption as initial concentration is increased. As the contact time is increased, adsorption increases only until it reaches its optimum adsorption which is 60 minutes contact time where saturation is reached. Increasing initial concentration however has different effect on adsorption on all system explained by the adsorption isotherms. The isotherms show that phenol has the fastest rate to form a monolayer (K and Q°) with the greatest binding strength (b) on silica gel. It is also observed that phenol and aniline formed a monolayer (1/n) on the surface of the silica gel and rice hull ash.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.Item Moss (Brachythecium sp.) and a filamentous green algae (Oedogonium sp.) as bunker oil sorbentsBautista, Norwell Brian C. (Division of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2007-04)Oil spills are very catastrophic and very destructive events. One way of controlling the dispersion of oil from these spills is by the use of sorbents. The procurement of commercial sorbents can be very costly. Thus, this study analyzed and evaluated the efficiency and effectivity of moss (Brachythecium sp.) and a green filamentous algae Oedogonium sp. as substitutes for commercial sorbents. Brachythecium sp. can grow in any moisture—rich environment and Oedogonium sp. algae grow freely in fish ponds and in any body of stagnant, oxygen-poor water. Thus, both samples are very abundant in the environment. Sorption capacity results showed that the moss Brachythecium sp. and the algae Oedogonium sp. can sorb five times and seven times its weight, respectively. In comparison, Peat Sorb, a commercial sorbent, was recorded to sorb 15 times its weight (Emedco, 2007). The minimum sorption capacity of the moss and algae samples was recorded to be approximately equal to their weight. The adsorption isotherms of both samples follow the Langmuir plot for monolayer adsorption. In the hexane capillary rise experiment, hexane rose significantly in ground moss (72.25 mm in 7 min.) and unground moss (64.80 mm in 7 min.) compared with unground algae (23.52 mm in 7 min.) and (20.70 mm in 7 min.), indicating that moss is more hydrophobic. In water, capillary rise, on the other hand, unground algae is a better medium (5.76 mm in 4 min) compared to the rest (ground algae - 4 mm, unground moss - 5.29 mm, and ground moss — 4.11 mm, all in 4 min.). Results also revealed that the moss Brachythecium sp. and the algae Oedogonium sp. expressed hydrophobic characters in the hexane-water system by remaining in the hexane layer after agitation. The moisture content of the algae (14.85%) is twice that of moss (7.94%). This gives the moss an advantage in oil sorption. The lipid contents of algae (15.58%) and moss (11.47%) do not comprise the majority of their biomass, but the lipids aid in increasing the samples’ affinity for non-polar substances. The samples may not sorb as effectively as the commercial sorbents, but they are abundant in the environment, thus, a cheaper alternative. Like Peat Sorb, which was processed from the biomass of Sphagnum sp. moss, the samples may undergo the same process that increases the hydrophobicity several-fold and gives oil-biodegradation capabilities.Item Bioaccumulation of cadmium, copper and lead by Hydrilla (Hydrilla vericillata)Baniago, Arjay C. (Division of Pysical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2007-04)Bioaccumulation of cadmium, copper, and lead by Hydrilla (Hydrilla verticillata) were tested to 5 different initial concentrations. The water contaminant sample was composed of mixed cadmium, copper and lead metals supplied as nitrate salts. These were analyzed for the decrease in concentrations at 24-hour intervals for 5 days using the SpectrAA 55B Atomic Absorption Spectrometer. Plants exposed only for 5 days were digested and analyzed. The plant growth was normal at lower concentrations and showed higher removal efficiency. H. verticillata showed maximum removal percentage on the 5th day of exposure at 5 mg L-1 for cadmium (90.47%) and copper (95.20%) but for lead was on the 1st day (96.74%). The order of metal ion removal and the actual uptake for the three metals by H. verticillata is Pb>Cu>Cd, but at lower concentration, cadmium was absorbed more than copper. The copper and lead uptakes by H. verticillata are superior as compared to other aquatic plants uptakes. Lead uptake at higher concentrations might be due to physicochemical adsorption of the metal to the plant components and not on metabolism-mediated uptake, because plant condition does not have an adverse effect on the uptakeItem Antioxidant property, total phenolics, manganese and iron content of humic acid obtained from Sta. Barbara, Iloilo artesian well waterBaltazar, Lenmark Anthony M. (Division of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)The town of Santa Barbara in Iloilo is famous for its reddish browncolored well water due to the presence of humic acid which makes up most of the water’s natural organic matter content. Because the well water is used by the local townsfolk for drinking and other domestic activities, it is imperative that a study must be made to assess its potential health benefits and risks. In this study, the DPPH radical scavenging activity of the extracted humic acid was investigated. It was determined that the sample contains antioxidants capable of reducing DPPH with an IC5o of 51.552± 0.652 ppm. Prussian Blue Assay for total phenolic content also showed that a 76.5 ppm humic acid sample has 14.169 ± 1.151 ppm in GAE. Flame-AAS analysis showed that the humic acid sample contains iron (0.8376 ± 0.0581 ppm). The manganese content of the sample was below the detection limit of the instrument. The results suggest that the humic acid extracted from the well water contains potential antioxidants which can be exploited for various commercial and medical applications.Item Mud crab (Scylla serrata) shells for the removal of humic acids from Santa Barbara well waterAsdillo, Reina Jean A. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2010-04)The chemical contamination of drinking water from a wide range of contaminants such as humic acids can potentially lead to health-related in living organisms, especially humans. In rural areas of the Philippines, the use of low cost methods to remove water pollutants is, therefore, of great interest. In this study, osterized mud crab (Scylla serrata) shells or exoskeletons from cooked crab wastes were used to remove humic acids from the Santa Barbara well water. Adsorption experiments were done to evaluate its capacity to remove humic acids from the well water. Adsorption Isotherms and Fourier Transform Infrared Spectroscopy were employed to study the characteristics of the adsorption of humic acids onto the OSSE (osterized Scylla serrata exoskeletons). Adsorption experiments showed that at an average 1.0010 g of OSSE and after six hours of agitation, an average 74.95% of humic substances were removed from 50 mL of Montinola, Santa Barbara well water sample. Isotherm experiments showed that the experimental data can be fitted in both Langmuir and Freundlich models with low K values of 0.0235 L/mg and 0.4450 (mg/g)(L/mg), respectively. Based on the results of the above experiments, OSSE is a good adsorbent for humic acids in well waters (although more research need to be done on the removal of the substances remaining in the water after OSSE treatment) and the U-OSSE (used osterized Scylla serrata exoskeletons) can possibly be recycled.Item Preparation and characterization of chitin-humic acid hybrid and chitin-humic acid hybrid hydrogel as absorbent for Cu(II)Balgos, Blyth Angela C. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2017-06)Gelatinous chitin was functionalized with humic acid to produce a chitinhumic acid hybrid. The gelatinous chitin was protonated using HC1 and humic acid was deprotonated by using NaOH in separate containers. The protonated gelatinous chitin and the deprotonated humic acid were then mixed to form Hie chitin-humic acid hybrid. A portion of the chitin-humic acid hybrid was used to prepare the chitin-humic acid hydrogel. The chitin-humic acid hybrid hydrogel was then prepared using 1,2,3,4- butanetetracarboxylic dianhydride(BTCA) as crosslinker. The chitin-humic acid hybrid hydrogel was then characterized using FT-IR and swelling test. The degree of swelling of the chitin-humic acid hydrogel was found to be 38.10 ± 3.06. It can also be inferred from the results of the swelling test that the chitin-humic acid hybrid hydrogel has a low crosslink density. Characterization by FT-IR suggested successful immobilization for the hybrid and BTCA crosslinking for the hydrogel. The potential of chitin-humic acid hybrid and chitin-humic acid hybrid hydrogel to adsorb Cu(II) in a solution was then evaluated. The process was done by subjecting the chitin-humic acid hybrid to Cu(II) adsorption. The results for Cu(II) adsorption test was subjected to a Shapiro- Wilk test for normality and was determined to have normally distributed data. One- sample T-test was then used to compare the adsorption capacity of the hybrid and hydrogel. The mean % Cu(II) Removal of the chitin-humic acid hybrid and chitinhumic acid hybrid hydrogel were 41.36 ± 2.35% and 51.21 ± 1.32%, respectively. Results suggested that the chitin-humic acid hybrid hydrogel has significantly higher % Cu(II) Removal compared to the chitin-humic acid hybridItem Treatment of Vibrio harveyi-infected Penaeus monodon using Alibutbut (Tabernaemontana pandacaqui Poir.) plant powderBacaling, Marivic T. (Division of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2005-04)The cytotoxicity test of crude methanolic leaf extract using Brine Shrimp Lethality Assay revealed that Alibutbut (Tabernaemontana pandacaqui Poir.) is safe to use in treating vibrio-infected penaeid shrimps. The effectiveness of the alibutbut powder against vibriosis was examined through the determination of the post-larvae 20 (PL 20) penaeid shrimp mortality and the water microbial assay after 48 hours. Percent penaied shrimp mortality (0-6.67%) and microbial count (2.91 x 10^4- 3.26 x 104 cfu/mL) of the plant treatments were significantly lower compared to the negative control (no treatment) that exhibited 50% penaeid shrimp mortality and a microbial count greater than 6.00 x 10^4 cfu/mL. The results of the experiment showed that Alibutbut plant powder is indeed effective in controlling Vibrio harveyi bacteria.Item Efficiency of constructed filters in removing heavy metals (Cd,Cu,Pb and Zn) from chemical wastewaterAlbaladejo, Anthony Salvador B. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2012-04)The presence of heavy metals at elevated concentrations is a major concern due to its toxic effects to aquatic organisms, plants and humans. Untreated wastewaters from chemistry laboratories could be the key source of heavy metal contamination if not properly processed before disposal to the environment. In this study, the efficiency of the constructed filter, made up of plant-based materials, in removing heavy metals (Cd, Cu, Pb and Zn) from chemical wastewater was determined. Characterization of the untreated and treated chemical wastewaters was also performed using different water quality parameters such as temperature, pH, TDS, TSS, COD, heavy metals and toxicity. Results show that the untreated chemical wastewater contains high concentrations of Zn, Cu, Pb and Cd which did not pass the Department of Environment and Natural Resources (DENR) standards and considered harmful when released to the environment. The physico-chemical characteristics, such as TSS and TDS, of the untreated wastewater also did not pass the standards set by DENR except for pH, temperature and COD. The quality of the treated wastewater failed to pass the DENR standards for TSS and TDS thus the constructed filter was not efficient in improving the said physico-chemical characteristics of the wastewater. Rice hull was efficient in removing Zn, Cu and Pb. Bagasse was efficient in removing Pb and saw dust was efficient in removing Cu. The constructed filter was able to significantly reduce the concentrations of heavy metals from 18-L chemical wastewater. The removal efficiency was not significantly different from the 9-L volume treatment. Pb concentration was within the DENR standards after treatment while Zn, Cu and Cd concentrations were above the requirement. The initial concentration of the metal in wastewater greatly affects the removal efficiency of the constructed filter. Furthermore, the constructed filter was able to minimize the toxicity of the chemical wastewater. These findings could be of significance in the design of the treatment facility that could address the problem of heavy metal pollution.Item Physico-chemical assessment of the groundwater in Barangay Mohon, Arevalo District, Iloilo CityAdenix, Kimberly V. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2017-06)Water analysis determines the stability and reliability of natural water sources. Determining the physical and chemical compositions of water would indicate its safety for use and consumption. In this scientific study, water analysis was conducted to evaluate the quality of potable water from eight water pumps, commonly used for drinking, in Brgy. Mohon, Arevalo District, Iloilo City. Aside from drinking, most residents also used these groundwater sources for cooking, bathing, washing, and laundry purposes. The parameters tested were pH, temperature, alkalinity, phosphate, nitrite, dissolved oxygen, and heavy metals (e.g., lead, copper, and cadmium) content. The analyses were conducted from February to April with same time of collection (9:00 am-12:00 nn) and the samples were stored under dark and cold conditions (4 °C). During the analyses, the following methods were used: titrimetric for alkalinity and dissolved oxygen content, colorimetric and UV/Vis spectrophotometry for phosphate and nitrite-nitrogen, and atomic absorption spectroscopy (AAS) for heavy metals. Results showed that all sampling sites were determined to have alkaline waters (7.29- 7.77), because of the high pH and alkalinity values. Also, it was found that the water sources contained very high phosphate levels (0.54-1.29 mg/L PO4-P) that contributed to very low DO levels (0.12-0.14 mg/L DO). Other parameters, such as nitrite-nitrogen and heavy metal determinations showed no significant difference based on the standard limits set by different environmental institutions.