Web-based monitoring and control to improve RO performance and reliability

Abstract

Application of RO membranes for water reclamation and desalination is growing significantly in recent years due to scarcity of water resource. In order to achieve stable operation and good performance, membrane system requires reliable monitoring and control in addition to skilled operating personnel. For industrial users of small to medium RO systems, operation failure and membrane damage are frequently observed due to inadequate technical knowledge of operating staff. With this in mind, Nalco has developed a web-based monitoring and control system, 3DT for Membrane (3DTfM), to assist small and medium scale users to achieve optimized system performance. In order to demonstrate its value, 3DTfM has been installed at a RO system treating boiler feed water at a power plant. This study is to illustrate the benefits of utilizing 3DTfM; namely stable antiscalant dosage, better ORP control, improved alarm management, and periodical service report of the system. After implementing 3DTfM, fluctuation of antiscalant dosage has been reduced from wider range of 0.5–10 ppm to narrower range of 1.8–2.2 ppm. In addition, exposure duration of ORP > 650 mV has also been reduced by 83%. It has also been noted that operation staff was able to perform timely Clean-In-Place (CIP) and necessary adjustment of RO system. Owing to stable control, CIP frequency was reduced for about 50%. In terms of tangible saving delivered by 3DTfM, it is estimated to be $10,000 and 18,000 for asset and chemicals, respectively.

Keywords:

• Cleaning
• Control
• Dosage
• Monitoring
• RO system

Notes

Presented at the 5th IWA-ASPIRE Conference, 8–12 September 2013, Daejeon, Korea