The document discusses biochemical oxygen demand (BOD) and chemical oxygen demand (COD), which are common methods for measuring water quality. BOD measures the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material in water over 5 days. COD measures the amount of oxygen required to chemically oxidize organic compounds in water, providing a faster analysis than BOD. Both BOD and COD are important for assessing the organic pollution load of wastewater and the efficiency of treatment plants. While COD correlates well with BOD, it does not distinguish between biodegradable and non-biodegradable organic matter. Real-time monitoring of BOD and COD can provide information on pollutant