IDE Technologies, a leading global provider of water treatment solutions, announced the Cherokee Metropolitan District water reuse installation is fully operational and producing a high water recovery rate of 90-95% with IDE’s Pulse Flow Reverse Osmosis (PFRO) technology. Originally constructed in 2010, the $45M project in southeast Colorado is a retrofitted and upgraded 4.8 MGD water reclamation facility designed to manage increasing raw wastewater total dissolved solids (TDS) levels and comply with the municipality’s decrease in permitted discharge limits.
The Cherokee Metropolitan District was experiencing raw water salinity levels exceeding 600 mg/L TDS and needed a solution to meet new discharge limits. After exploring several options, they decided to incorporate a new reverse osmosis process supplied by IDE. The plant included a headworks system with fine screening and grit removal, the conversion of two of the four existing SBRs to MBRs, and IDE’s high-recovery reverse osmosis (RO) system. The end result is a plant that uses 9 MGD MBR and a 1.6 MGD high-recovery RO system designed to enable RO permeate to be mixed with MBR filtrate, helping dilute the final effluent to below the 400 mg/L permit level.
“We are thrilled to see the successful operation of the Cherokee Metropolitan District’s water reclamation facility,” said Roi Zaken Porat, Director of Water Treatment Process, IDE. “IDE is committed to helping municipalities around the world overcome their water challenges to comply with regulation and ensure the local population has access to clean, high-quality water for residential and commercial use. IDE’s PFRO sets an industry standard on recovery rates and we look forward to continuing to implement this technology in many existing, and future, water facilities in need of a solution.”
IDE’s PFRO is a semi-batch process that implements alternating hydraulic and osmotic conditions to significantly reduce the tendency for scaling and biofouling. Its unique design eliminates the need for the three to four stages that are typically required to reach such high recovery rates. PFRO uses a single-stage RO that continuously changes the operation mode from dead-end filtration to brine discharge mode by opening and closing a brine valve – achieving 90-95% recovery rates with a silica concentration of more than 250 ppm in the brine stream. With high-recovery RO, Cherokee Metropolitan District was able to use the eastern half of its site for evaporation ponds in place of a deep well injection, a significant cost savings.
IDE’s PFRO technology is also in use at the Pismo Beach Plant in California.