Green fabrication of paper-based chromium (vi) detector using sugarcane bagasse and tannin-crosslinked polyethyleneimine for water quality monitoring/
Ethan Domini A. Bautista, Rochelle Ann V. Insigne, Marriane Angel A. Mandariaga, and Nathalie Joy M. Quezada.--
- Manila: Technological University of the Philippines, 2025.
- viii, 133pages: 29cm.
Bachelor's thesis
College of Science.--
Includes bibliographic references and index.
Preliminary water quality assessments identified chromium (Cr) as a significant contaminant in the Pasig River, emphasizing the need for continuous and real-time monitoring. However, current detection methods are costly, complex, and require technical expertise, limiting them to centralized laboratories. This study developed a low-cost,rapid, and portable method for selective Cr(VI) detection using sugarcane bagasse (SCB) and tannin-crosslinked polyethylenimine (TA-PEI) by using the color-changing complex instigated by the reduction of Cr(VI) in solutions as a colorimetric standard used to quantify chromium concentrations. After product optimization and comparison of methods, the colorimetric data collected from known Cr(VI) solutions yielded a strong linear regression with R2=0.9865 using the Eluate method, demonstrating a proportional relationship between blue channel intensity (IB) and Cr(VI) concentration. The selectivity of the chromogenic agent was also validated through tests with copper (Cu) and the organic pollutant nonylphenol, which showed no significant interference with Cr adsorption or the resulting color intensity changes. In field testing, the eluate method amounted to an estimated Cr concentration of 0.0724 ppm; while not yet validated for field deployment,
the results provide a reliable foundation for laboratory simulations. Moreover, the PEI-TA- coated SCB showed excellent adsorption of Cr in lower concentrations, with a 76% Cr
adsorption in 0.5 ppm solution and an adsorption capacity of 2.45 mg/g, all in consistent conditions and a pH value of 3. Additionally, the conducted community survey findings indicate that although awareness of environmental monitoring and stewardship is limited, residents are receptive to sustainable practices and open to adopting the detection method developed in the study.