1 / 8

Chlorine-Resistant RO & NF Membranes

Chlorine-Resistant RO & NF Membranes. Benny D. Freeman University of Texas at Austin. Problem: a shortage of clean water. 41% of the Earth’s population (2.3 billion) live in water-stressed areas; 3.5 billion by 2025. The number of people living without clean, piped water is 1 billion (WHO).

euphemia
Télécharger la présentation

Chlorine-Resistant RO & NF Membranes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chlorine-Resistant RO & NF Membranes Benny D. Freeman University of Texas at Austin

  2. Problem: a shortage of clean water • 41% of the Earth’s population (2.3 billion) live in water-stressed areas; 3.5 billion by 2025. • The number of people living without clean, piped water is 1 billion (WHO). • Water shortages limit economic development and threaten human life.

  3. Desalinization market • There are currently more than 15,000 desalinization plants worldwide (1/4 in US). • Membranes (reverse osmosis and nano-filtration) provide the most economical desalinization. • Costly pre-treatment of water (chlorination and dechlorination) is required before membranes to reduce membrane fouling. • Sources: • Water Desalinization Report, 42(35), 1, 2006 • www.bp.com • Ultrapure Water, 23(3), 14, 2006

  4. Why chlorine is used in water treatment • Bacteria-laden untreated water kills more than 1.1 billion people every year in developing countries • Chlorine is the most economical disinfectant for deacti-vation of pathogenic microorganisms in drinking water. • Over 98% of all water treatment facilities in the U.S. disinfect water with chlorine and chlorine-based products. • So what’s the problem? Chlorine degrades desalination membranes, causing reduced salt rejection and premature end of life.

  5. Chlorine attacks current desalinization membranes Membranes A through D: commercial membranes (Source: T. Knoell, Ultrapure Water, April 2006, pp.24-31)

  6. Current desalination process Feed water Chlorinate Dechlorinate (Free chlorine < 0.01 ppm) Polyamide desalination membrane Rechlorinate To protect membrane from chlorine Product water

  7. Chlorine exposure time 0 h 8 h 16 h 24 h 32 h New membrane 2 New membrane 1 Commercial RO membrane UT/Virginia Tech innovation:Chlorine-tolerant membranes

  8. Proposed new process & advantages Chlorinate New membrane Feed water Product water • Extended membrane lifetime • Easy maintenance and operation • Process intensification • Potential spin-off applications (e.g., pervaporation and electrodialysis) • Significant cost savings through the elimination of dechlorination required by current membranes

More Related