A two-stage dissolved air flotation saturator configuration for significant microbubble improvement

Area of Science:

• Environmental Engineering
• Chemical Engineering
• Water Treatment Technologies

Background:

• Suspended contaminants like algae and oils in water and wastewater require efficient removal systems.
• Dissolved air flotation (DAF) is a standard technology for removing such contaminants.
• Optimizing microbubble generation is crucial for enhancing DAF efficiency.

Purpose of the Study:

• To introduce and evaluate a novel two-stage (TS) bubble enhancement setup for DAF systems.
• To compare the performance of the TS configuration against traditional empty and packed configurations.
• To assess the impact of pressure and flow rate on microbubble characteristics in the TS system.

Main Methods:

• An industrial-scale pilot DAF system was utilized.
• Three configurations were tested: empty, packed, and the novel two-stage (TS) setup.
• The TS system involves a secondary pressurization step for nucleated microbubbles before release.

Main Results:

• The TS configuration produced the highest volume of released air and the smallest microbubbles.
• Bubble quality from the TS system at 3 atm exceeded that of the standard configuration at 7 atm.
• The TS system demonstrated superior performance over packed and empty configurations.

Conclusions:

• The novel TS setup offers a more energy-efficient and cost-effective solution for DAF systems.
• The enhanced microbubble generation by the TS system improves contaminant removal efficiency.
• Potential for integrating the TS system's feed extraction within the DAF tank's contact zone exists for practical applications.