Sludge Reduction in the Activated Sludge Process Strengthened by Enhanced Ozonation Oxidation

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Chemical Engineering

Background:

• Sludge disintegration is crucial for efficient wastewater treatment.
• Conventional methods often face challenges in optimizing ozone utilization and sludge reduction.
• Developing advanced reactor designs is essential for enhancing treatment processes.

Purpose of the Study:

• To design and evaluate a novel radial-axial mixer and microbubble ozone reactor for sludge disintegration.
• To assess the effectiveness of the new reactor in improving sludge disintegration and ozone utilization.
• To investigate the impact of feeding ozonated sludge into an activated sludge process on effluent quality and sludge yield.

Main Methods:

• Batch studies were conducted using the novel radial-axial mixer and microbubble ozone reactor.
• Ozone dosages ranged from 0.02 to 0.3 gO3/gTSS at pH 10.
• A 60-day activated sludge process was operated with ozonated sludge feeding.

Main Results:

• The novel reactor demonstrated significantly higher sludge disintegration ratios compared to conventional reactors (average increase of 17 ± 0.83%).
• Ozone utilization was notably enhanced by the new reactor design.
• A sludge reduction efficiency of 95% was achieved when integrating ozonated sludge with the activated sludge process.
• Effluent quality, including chemical oxygen demand (COD) and suspended solids (SS), remained within acceptable discharge limits despite slight increases.

Conclusions:

• The radial-axial mixer and microbubble ozone reactor effectively enhances sludge disintegration and ozone utilization.
• Integrating sludge ozonation with activated sludge processes is a viable strategy for substantial sludge reduction.
• This combined approach can yield high-quality effluent while minimizing sludge production.