Optical characteristics and numerical simulations of microalgae and plastic litter in surface waters using portable 405-nm LD-based fluorescence lidar
Date of Publication
2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Physics
Subject Categories
Optics | Physics
College
College of Science
Department/Unit
Physics
Thesis Advisor
Maria Cecilia D. Galvez
Defense Panel Chair
Edgar A. Vallar
Defense Panel Member
Christopher T. Que
Ofelia T. Rempillo
Prane Mariel B. Ong
Tatsuo Shiina
Abstract/Summary
Water pollution has been an emerging problem resulting from poor waste management which may lead to serious health and sanitation hazards. Some of the water pollutants include chemicals, trash, bacteria, parasites, and microalgae. Optical techniques, including absorbance-fluorescence, FTIR, and Raman spectroscopy, have been extensively utilized for the detection of suspended particles on surface waters. While these techniques offer accurate analytical results for the detection of suspended particles like microalgae and microplastics, the data acquisition process typically exceeds an hour, making them time-consuming methods. Considering the environmental, economic, and health impacts, and their rapid spread and persistence, the need for real-time, in-situ monitoring of microalgae and microplastics is needed.
This study aims to develop a portable LD-based fluorescence Light Detection and Ranging (Lidar) system for microalgae and plastic litter detection in surface waters and investigate their optical properties. Advanced algorithms were employed to differentiate between microalgal and microplastic fluorescence spectra, enabling accuracy and reliability in detection.
The experiments were carried out in a controlled environment using a fluorescence lidar system with 405 nm excitation wavelength to determine the fluorescence signals of several plastics at 470 nm emission wavelength. Simultaneous detection of PET plastic and Chlorella vulgaris were also observed to determine the fluorescence influence of chlorophyll in surface waters. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy was employed to study the chemical composition of the plastics used before and after being submerged in the water. Scanning electron microscopy (SEM) and high-resolution camera microscopy were used to analyze the morphology of the submerged PET samples. This study provides a basis for a novel in-situ technique using a fluorescence lidar system for submerged and transparent plastics in surface waters.
Abstract Format
html
Language
English
Format
Electronic
Keywords
Fluorescence spectroscopy; Water quality; Microalgae; Plastic scrap
Recommended Citation
Cadondon, J. G. (2024). Optical characteristics and numerical simulations of microalgae and plastic litter in surface waters using portable 405-nm LD-based fluorescence lidar. Retrieved from https://animorepository.dlsu.edu.ph/etdd_physics/7
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Embargo Period
11-26-2024
