Introduction 

Wastewater treatment efficiency depends on removing contaminants in multiple stages. One of the most important indicators used in treatment design and regulation is biochemical oxygen demand. High BOD levels represent a high organic load, requiring advanced treatment methods to meet environmental standards. Dissolved air flotation (DAF) provides a cost-effective and powerful solution for reducing suspended solids and oils while supporting downstream treatment. 

Measuring Biochemical Oxygen Demand and Its Impact 

Biochemical oxygen demand (BOD) quantifies how much oxygen microorganisms need to break down organic matter present in wastewater. A high BOD value means the water contains a large amount of biodegradable content, which can generate odor, support bacterial growth, and harm aquatic environments. 

Managing BOD effectively is essential for wastewater reuse, safe discharge, and regulatory compliance. Pretreatment strategies designed to remove solids before biological treatment are especially important in reducing BOD. 

Dissolved Air Flotation as a Pretreatment Solution 

Dissolved air flotation is widely used in wastewater systems requiring suspended solids removal. The method injects many microbubbles into the wastewater stream. When bubbles attach to solids, oils, and grease, the materials become buoyant and float to the surface. 

DAF systems are effective for industries generating oily wastewater or solid-rich effluent. The technology supports pretreatment, reuse systems, phosphorus removal, and deep purification applications. 

By removing suspended solids and oils early in treatment, DAF significantly reduces the source of organic pollutants contributing to biochemical oxygen demand. This improves system stability and protects biological treatment processes from overload. 

Conclusion 

Reducing biochemical oxygen demand is a key objective in modern wastewater treatment. Integrating dissolved air flotation enhances pollutant removal efficiency and strengthens overall treatment performance. As the demand for clean water and sustainable solutions increases, the use of DAF systems becomes an essential step in achieving cleaner, safer wastewater discharge and improved resource recovery.