Water surface contacting cover system--the basic study for improving the oxygen transfer coefficient and the BOD...

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Chemical Engineering

Background:

• Standard aeration basins (SRAS) in sewage treatment plants face limitations in oxygen transfer efficiency.
• Optimizing oxygen transfer is crucial for effective wastewater treatment and pollutant removal.

Purpose of the Study:

• To evaluate a novel water surface contacting cover system (WSCCS) for enhancing oxygen transfer in aeration basins.
• To compare the performance of WSCCS against standard aeration basins (SRAS).
• To determine optimal configurations for WSCCS components.

Main Methods:

• Laboratory-scale and pilot-scale experiments were conducted using tap water.
• A novel WSCCS, featuring a cover plate and a slant plate, was compared to a standard aeration basin (SRAS).
• The oxygen transfer coefficient (KLa) was measured, and optimal slant plate angles and diffuser distances were determined.

Main Results:

• Adding a slant plate increased KLa by approximately 15%; optimal angle was 10 degrees.
• The cover plate alone increased KLa by about 25% (lab-scale) and 20% (pilot-scale).
• The combined WSCCS achieved over 35% increase in KLa, and improved BOD removal by 3% in a full-scale plant.

Conclusions:

• The WSCCS significantly enhances oxygen transfer efficiency in aeration basins.
• WSCCS offers a viable solution for improving wastewater treatment performance.
• Optimized WSCCS design, including slant plate angle and diffuser placement, maximizes oxygen transfer benefits.