Abstract

In this paper, a bench scale RO/EDI system for high pressure boiler feed water is reported. Technical and economical aspects were evaluated to determine whether RO/EDI system is feasible to replace existing ion exchange bed. The EDI module used in this study was all filled electrodeionization type with mixed bed ion exchange filler. All product quality of demin water produced by RO/EDI during bench scale test shows good water quality (conductivity: 0.3–0.4μs/cm; pH: around 6.3; silica: 0.00–0.01ppm; and Na: <0.003ppm), even better than existing demin water system specification (conductivity: <5μs/cm; pH: 6.5–8.5; silica: <0.12ppm; and Na: <0.3ppm), except pH. Dissolved CO2 in water (HCO3−) is a suspected substance which is present in RO/EDI product water that influences the pH. The specific water cost of RO/EDI was US$0.53/m3 lower than existing ion exchange beds, US$0.66/m3. The main operating costs were membrane replacement and electricity cost. Long term performance of the RO/EDI system showed stable and high product quality even during periods when the feed solution has relatively high conductivity.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.