Extraction of nutrients from foam in a membrane activated sludge system

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Advanced Oxidation Processes

Background:

• Foams in enhanced biological phosphorus removal (EBPR) processes pose operational challenges.
• Solubilization of nutrients and metals from EBPR foam is crucial for resource recovery.
• Effective foam control methods are needed to improve wastewater treatment efficiency.

Purpose of the Study:

• To assess the feasibility of microwave-enhanced advanced oxidation process (MW-AOP) for treating EBPR foam.
• To evaluate the reduction of solids and solubilization of nutrients and metals from foam.
• To determine the potential for nutrient recovery and cost reduction.

Main Methods:

• Application of MW-AOP with a low dose of hydrogen peroxide to EBPR foam.
• Analysis of chemical oxygen demand (COD) solubilization.
• Quantification of phosphate, volatile fatty acids, ammonia, and metal (Ca, K, Mg) release.

Main Results:

• Over 50% of total COD was solubilized, indicating effective foam solids destruction.
• Significant solubilization of phosphates, volatile fatty acids, and ammonia was achieved.
• Release of calcium, potassium, and magnesium was observed, enabling nutrient recovery.

Conclusions:

• MW-AOP is a feasible and efficient method for EBPR foam treatment and control.
• The process facilitates nutrient and metal recovery, offering additional economic benefits.
• Eliminates the need for sludge thickening pretreatment, potentially reducing energy costs.