Performance and economic evaluation of a pilot scale embedded ends-free membrane bioreactor (EEF-MBR)

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Bioreactor Design

Background:

• Membrane fouling is a significant challenge in conventional membrane bioreactors (MBRs).
• Existing MBR configurations often struggle with maintaining stable performance and high effluent quality, especially with high organic load wastewater.
• There is a need for innovative MBR designs that mitigate fouling and improve operational efficiency.

Purpose of the Study:

• To develop and evaluate a novel embedded ends-free membrane bioreactor (EEF-MBR) to address membrane fouling.
• To assess the performance of a pilot-scale EEF-MBR in terms of permeate flux, selectivity, and chemical oxygen demand (COD) removal.
• To determine the economic viability and scalability of the EEF-MBR for large-scale wastewater treatment.

Main Methods:

• A pilot-scale EEF-MBR unit was constructed with an integrated granular activated carbon bed fluidized by aeration.
• The EEF-MBR was operated for 140 hours, treating wastewater with high organic matter content.
• Performance metrics including permeate flux, operating pressure, and COD removal efficiency were monitored.

Main Results:

• The EEF-MBR demonstrated high COD removal efficiency, exceeding 99% within the first hour of operation.
• Permeate flux ranged between 2 and 10 L.m⁻².h⁻¹ under operating pressures of 0.07-0.2 bar.
• Pilot-scale data supported the design of a 1200 m³.day⁻¹ large-scale EEF-MBR, showing cost-effectiveness at 10 L.m⁻².h⁻¹ flux.

Conclusions:

• The novel EEF-MBR configuration effectively overcomes fouling issues associated with conventional MBRs.
• The EEF-MBR achieves excellent wastewater treatment performance, characterized by high COD removal and stable permeate flux.
• Economic analysis indicates that the EEF-MBR is a cost-effective solution for large-scale wastewater treatment, with an estimated additional cost of $0.25/m³ and a 3-year payback period.