Pulse Flow RO - The new RO technology for waste and brackish water applications

Abstract

Pulse Flow Reverse Osmosis (PFRO) technology is a new, innovative method for operating Reverse Osmosis water reuse systems that enables high recovery, high flux and Chloramine-free operation. PFRO™ constantly changes the osmotic and hydraulic conditions, thus greatly diminishing biofouling and scaling. PFRO technology was demonstrated in a municipal wastewater (WW) treatment facility at Pismo Beach, CA, from October 2018 until October 2019, using secondary effluent of a municipal wastewater plant as source water. The unit operated with an average flux of 16.5 gfd (28 LMH), which is 50% higher than the standard design of 11 gfd (18–19 LMH). Specific flux was 0.12 GFD/PSI - about 25% higher than most well-operated wastewater reuse facilities that operate at the same recovery with specific flux of 0.09–0.1 gfd/psi. The unit operated at 86% recovery in a single RO stage. No chloramine was dosed, thus no disinfection byproducts were formed. The chloramine-free operation generates permeate with an Ultraviolet Transparency (UVT) value of about 100%, thereby saving 30–40% on Capital (CAPEX) and Operational Expenditure (OPEX) in the final Ultra Violet/Advanced Oxidation Process (UV/AOP) stage. The overall water cost in this process is 14–28% lower than a similar standard Fully Advanced Treatment (FAT) water reuse process.