EDR life-cycle costs same as for MF/RO says report
There is very little difference in life-cycle costs for desalination of reused water between reverse osmosis (RO) with microfiltration (MF) pretreatment and electrodialysis reversal (EDR).This is the prime conclusion of a new report from the WateReuse Association in the USA, A Full-Scale Performance and Cost Comparison Between Electrodialysis Reversal and Microfiltration/Reverse Osmosis, which concludes that utilities will need to determine if there are any additional plant-specific factors that could impact the process costs.
MF/RO and EDR have both been successfully applied to desalting in water reuse, but a full comparison of the actual lifecycle costs of existing full-scale systems has never been documented. This report is intended to assist engineers, utility managers, and planners in selecting a membrane process for desalting recycled water.
Authored by principal investigator and project manager, R Shane Trussell of Trussell Technologies, this report says that the need to reduce the salinity of recycled water is becoming more widespread, as wastewaters have become more saline and recycled water consumers have started demanding a higher quality product.
Recently, the regulatory community in the US has indicated the need to desalinate recycled water, and the California State Water Board has drafted a document (Policy for Water Quality Control for Recycled Water) that requires agencies to prepare basin-specific salt and nutrient management plans by 2014.
Because their life-cycle costs are so similar, the report says that a utility might also want to consider some of the non-economic factors that separate the two desalination technologies, such as removal of constituents other than salt, carbon emissions, potential hazards and process reliability.