Energy and greenhouse gas life cycle assessment and cost analysis of aerobic and anaerobic membrane bioreactor systems: Influence of scale, population density, climate, and methane recovery

Abstract

This study calculated the energy and greenhouse gas life cycle and cost profiles of transitional aerobic membrane bioreactors (AeMBR) and anaerobic membrane bioreactors (AnMBR). Membrane bioreactors (MBR) represent a promising technology for decentralized wastewater treatment and can produce recycled water to displace potable water. Energy recovery is possible with methane generated from AnMBRs. Scenarios for these technologies were investigated for different scale systems serving various population densities under a number of climate conditions with multiple methane recovery options. When incorporating the displacement of drinking water, AeMBRs started to realize net energy benefits at the 1 million gallons per day (MGD) scale and mesophilic AnMBRs at the 5 MGD scale. For all scales, the psychrophilic AnMBR resulted in net energy benefits. This study provides insights into key performance characteristics needed before an informed decision can be made for a community to transition towards the adoption of MBR technologies.

Exploring the limits of anaerobic biodegradability of urban wastewater by AnMBR technology

“…(ii) lower energy consumption because no aeration is required. According to Pretel et al, (2014) in mild/warm climates AnMBR technology could be a net energy producer when treating low sulfate-loaded wastewater 6 ; (iii) lower greenhouse gas emissions, especially when methane is recovered from permeate 7 ; and (iv) potential resource recovery because biogas energy and nutrient enriched fertigation water are obtained from the anaerobic degradation process.…”

Membrane processes

“…Mannina, Capodici, Capodici, Conseza, and Trapani (2018) further modeled GHG emissions in an IFAS process MBR and found a large variability depending on the carbon to nitrogen ratio. Cashman et al (2018) completed a life cycle assessment on GHG and energy, along with a cost analysis to provide various key performance characteristics needed when evaluating MBR technologies.…”

“…Cashman et al. (2018) completed a life cycle assessment on GHG and energy, along with a cost analysis to provide various key performance characteristics needed when evaluating MBR technologies.…”

Human Health, Economic and Environmental Assessment of Onsite Non-Potable Water Reuse Systems for a Large, Mixed-Use Urban Building

“…The influence of treatment system capacity, degree of decentralization and treatment system technology has been evaluated using life cycle assessment (LCA) [23][24][25], LCA and life cycle cost assessment (LCCA) [26] and QMRA [10]. Both Cashman et al [26] and Kavvada et al [24,25] found that design flow or capacity economies of scale strongly influenced cost and environmental performance of decentralized membrane bioreactors (MBRs), with clear advantages for larger systems. However, they only evaluated larger, community-scale NPR systems, which have different distribution and collection requirements and pathogen risk profiles than single building systems.…”

“…AeMBRs are a common, commercially viable treatment option (Hai et al, 2019). AnMBRs were investigated to explore the energy recovery potential of onsite wastewater treatment (Cashman et al, 2018). RVFWs were selected as a lower-energy, natural treatment option that relies on active recirculation to achieve a smaller land requirement than traditional constructed wetlands (Arden and Ma, 2018;Gross et al, 2007).…”