Micro-Oxygenation in Upflow Anaerobic Sludge Bed (UASB) Reactors Using a Silicon Membrane for Sulfide Oxidation

Area of Science:

• Environmental biotechnology
• Wastewater treatment
• Biogas upgrading

Background:

• Sulfide in biogas negatively impacts its quality.
• Microaeration is a known sulfide removal method.
• Limited data exists on microaeration in upflow anaerobic sludge bed (UASB) reactors.

Purpose of the Study:

• To investigate silicon membranes for oxygen dosing in UASB reactors.
• To evaluate internal versus external membrane configurations for sulfide removal.
• To assess the impact on biogas quality and operational parameters.

Main Methods:

• Testing two silicon membrane configurations: internal and external module.
• Monitoring sulfide concentrations in liquid effluent and biogas.
• Quantifying methane losses and oxygen consumption.
• Calculating sulfide conversion rates.

Main Results:

• The external membrane configuration was more practical and effective for sulfide oxidation.
• Sulfide concentrations in effluent and biogas were reduced.
• A sulfide conversion rate of 2.4 g-S m² d^-1 was achieved with the external setup.
• Methane losses of approximately 9% were observed due to non-selective oxygen transfer.
• Oxygen consumption exceeded stoichiometric requirements.

Conclusions:

• External silicon membrane microaeration is a viable method for sulfide removal in UASB reactors.
• Optimization of membrane area is crucial for system efficiency and minimizing methane loss.
• Further research may be needed to improve oxygen selectivity and reduce operational costs.