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Committee Member: search.filters.committeemember.Salac, Edcyl Lee O.Degree: search.filters.degree.Bachelor of Science in Chemistry

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    Physico-chemical assessment of the groundwater in Barangay Mohon, Arevalo District, Iloilo City
    Adenix, 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.
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    Smartphone-based colorimetric reader for phosphate analysis
    Acasio, Christian Jake M. (Division of Social Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2017-06)
    A smartphone-based colorimetric reader (SBCR) was developed for the analysis of phosphate in water and soil. The developed smartphone-based colorimetric reader was designed to be portable and cost-effective tool for analysis of phosphates, thus help in addressing inaccessible laboratory-based analysis, as well as contribute to soil and water nutrient monitoring and management. The SBCR was composed of a colorimetric analyzer box, constructed from cardboards, a 96-well flat-bottom transparent microtiter plate that was used to hold the solutions and a bottom-based illumination was provided by a gadget. To help improve the performance of the SBCR, various physical factors were controlled. The focal length, the bottom illumination intensities and comparison of smartphones were all evaluated in order to determine at which conditions these operating parameters gave a better sensitivity. The operating parameters selected were 15 cm for the height between the smartphone and the 96-well MTP, 0% illumination setting, which was offered by the application software used to provide for the light from the gadget, and the usage of Phone A for the image acquisition of the analysis. The preliminaries gave a basis on the operating parameters used for the SBCR. For the phosphate analysis, the red channel was chosen for analysis of the image since at this channel the sensitivity was at the highest compared with the green and blue channels. The developed method was then evaluated for its analytical characteristics. It has a working range of 0.20-0.70ppm, LOD and LOQ of 0.06±0.18 ppm and 0.18±0.06 ppm, respectively, an intraday precision (%RSD) lower than 2% and inter-day precision of 1.46% (%RSD). In addition, the SBCR analysis application on water and soil samples showed no significant difference between the results from analysis done using the spectrophotometric method. The experimental results suggest that the SBCR method could be applied for phosphate analysis for both water and soil samples.