Quantitative estimation of dissolved oxygen (DO) in water samples: Principles, methods, and environmental significance

Dissolved oxygen (DO) content in water is crucial for assessing aquatic ecosystem health and quality. It is influenced by factors like temperature, pressure, salinity, and the presence of photosynthetic organisms (Sawyer et al., 2003). Colder water holds more dissolved oxygen than warmer water, while higher pressures allow more oxygen to dissolve. Oxygen is primarily sourced from atmospheric exchange and photosynthesis, while human activities like pollution and fertilizer use can also affect dissolved oxygen levels. Low levels can cause stress, reduced growth rates, and mortality in aquatic animals, disrupting nutrient cycling and ecosystem balance. Monitoring dissolved oxygen levels is essential for understanding and managing aquatic environments, identifying pollution sources, and implementing strategies to protect and restore aquatic habitats (Metcalf and Eddy, 2013).