Modeling Cost, Energy, and Total Organic Carbon Trade-Offs for Stormwater Spreading Basin Systems Receiving Recycled Water Produced Using Membrane-Based, Ozone-Based, and Hybrid Advanced Treatment Trains

Abstract

To address water scarcity, cities are pursuing options for augmenting groundwater recharge with recycled water. Ozone-based treatment trains comprising ozone and biologically activated carbon potentially offer cost-effective alternatives to membrane-based treatment, the standard process for potable reuse in numerous countries. However, regulations in multiple states effectively limit the extent to which ozonebased treatment alone can produce recycled water for groundwater recharge. To investigate the trade-offs between treatment costs and regulatory constraints, this study presents methods for modeling and optimizing designs for (1) producing recycled water using membranebased treatment, ozone-based treatment, and hybrid treatment trains comprising ozone-based treatment with a membrane sidestream, and (2) delivering that water to stormwater spreading basins. We present a case study of Los Angeles, CA, to demonstrate the model's application under realistic conditions, including regulations that limit spreading recycled water based on its concentration of total organic carbon and the extent of dilution. While the membranebased treatment train exhibits economies of scale, we demonstrate how regulatory constraints create a diseconomies of scale effect for hybrid treatment systems because larger scales necessitate a higher proportion of recycled water undergo membrane treatment. Nevertheless, relative to membrane-based treatment, we identify opportunities for ozone-based or hybrid treatment trains to reduce treatment costs and energy use by up to 62% and 59%, respectively, for systems with up to 1 m 3 /s (23 million gallons per day) mean water recycling rate, potentially lowering the barrier for decentralized water recycling systems. This modeling approach could inform planning and policy regarding recycled water projects for groundwater recharge through spreading basins and, with additional modification, other potable reuse applications.

Evaluating the sustainability of indirect potable reuse and direct potable reuse: a southern Nevada case study

“…The RO process was assumed to achieve 90% water recovery and 99% TDS rejection (DDW, ). Overall recovery from conventional MF‐RO might be as low as 70%–80% (Bradshaw et al, ; Trussell et al, ), but 90% was assumed to be a best‐case scenario. The second treatment train (DPR 2), which is a potentially more sustainable alternative (Gerrity et al, ), included ultrafiltration (UF), O 3 , biological activated carbon (BAC), and UV AOP.…”

“…When considering various water supply alternatives, the evaluation and optimization of life cycle cost can be invaluable to the decision‐making process (Bradshaw, Ashoori, Osorio, & Luthy, ). A more comprehensive triple bottom line analysis might even be warranted because of its ability to simultaneously consider the social, environmental, and economic implications of an engineering design (Haak, Sundaram, & Pagilla, ; Schimmoller, Kealy, & Foster, ; Schoen et al, ).…”

“…With respect to social considerations, the recent literature demonstrates that, when designed and operated properly, potable reuse systems provide adequate protection of public health (Amoueyan, Ahmad, Eisenberg, & Gerrity, ; Amoueyan, Ahmad, Eisenberg, Pecson, & Gerrity, ; Chaudhry, Hamilton, Haas, & Nelson, ; Pecson et al, ; Pecson, Trussell, Pisarenko, & Trussell, ; Soller, Eftim, Warren, & Nappier, ). Particularly in California, potable reuse treatment trains often use both low‐pressure and high‐pressure (i.e., reverse osmosis [RO]) membranes, but when not mandated by local regulations or necessitated by salinity management, the use of membranes may lead to excessive costs or overall sustainability concerns (Bradshaw et al, ; Schimmoller et al, ). Alternative treatment trains using ozone (O 3 )‐biofiltration have been identified as “equivalent” on the basis of public health (Trussell, Salveson, Snyder, Trussell, & Gerrity, ) and are more cost and energy efficient (Gerrity et al, ; Herman, Scruggs, & Thomson, ), but these benefits must be evaluated against certain water quality limitations, including higher concentrations of total organic carbon (TOC) and total dissolved solids (TDS) in the final product water.…”

System Modeling, Optimization, and Analysis of Recycled Water and Dynamic Storm Water Deliveries to Spreading Basins for Urban Groundwater Recharge

“…Last, users could adapt this modeling framework to investigate the effect of policy or regulations on these systems. For example, a forthcoming study (Bradshaw et al, ) incorporates regulatory requirements to dilute certain types of recycled water for water quality purposes. In all cases, life cycle assessment could inform the impacts of various infrastructure designs on environmental factors outside our study's scope.…”

Membrane bioreactors for hospital wastewater treatment: recent advancements in membranes and processes

“…Consequently, MBRs have shown increased removal of enteric viruses in comparison to activated sludge treatment [21]. Also, MBR technology shows cost-effective with higher efficiency and low energy consumption [22], providing an advanced method to effectively separate complex contaminant mixtures and pathogenic microbes from wastewater [23].…”