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 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 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.