Modeling and Life Cycle Analysis of a Membrane Bioreactor-Membrane Distillation Wastewater Treatment System for Potable Reuse
Authors
Phillips, James
Issue Date
2022
Type
Thesis
Language
Keywords
Alternative Title
Abstract
With much of the world’s available water resources declining due to climate change and anthropogenic factors, wastewater treatment for potable reuse has become an important water management strategy and method of water recovery. A promising and effective method of wastewater treatment, membrane bioreactors (MBR) have the ability to achieve higher quality effluent, produce less excess sludge waste, and have reduced footprint compared to traditional secondary wastewater treatment methods such as conventional activated sludge (CAS). Traditionally used for desalination, air gap membrane distillation (AGMD) can be used as an effective tertiary wastewater treatment system and can be integrated with waste heat to achieve reduced energy consumption compared to other advanced treatment methods such as reverse osmosis (RO). Coupling MBR with MD can therefore result in an effective and energy efficient method of potable reuse; however, inconclusive research on the environmental impacts and sustainability of a hybrid MBR-MD system has resulted in a wide research gap. This study used physical and empirical models to obtain operational data for an MBR-MD hybrid wastewater treatment system and Baseline indirect potable reuse facility. A comparative life cycle analysis (LCA) was subsequently conducted for the MBR-MD and Baseline systems using modeled data. Results showed an average 48.7% reduction in environmental impacts for the MBR-MD system using 100% waste heat for AGMD; however, without waste heat the environmental impacts of MBR-MD are significantly higher than the Baseline with average impacts ranging from 218% to 1,400% greater than the Baseline. This research can help determine the overall sustainability and feasibility of the MBR-MD system compared to existing wastewater treatment infrastructure. Using the LCA process and gathering relevant environmental impacts for both systems, this study will identify areas of improvement of an MBR-MD system and could help improve the environmental sustainability of existing wastewater treatment and potable reuse infrastructure.