Ultrafiltration fouling control Demineralized water backwashing Louis Lagardère April-July 2009

Content 1. Introduction (theory) 2. Experiment and Installation of the setup 3. Results 4. Conclusion 5. Recommendation 1/

1. Introduction (theory) Demi water is better than UF permeate for backwashing (surface water) Difference demi water/ UF permeate Impact of sodium : 2/

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2. Experiment and installation of the setup Scheme of the setup 4/

Experimental setupSyringe pumps PLC controller Membrane module 5/

Material : - UF membrane : UFC M5 0.8, Norit X-Flow - Pumps : 1 NE1010 pump (backwashing), 1 DUAL-NE1010 (continuous filtration) Filtration protocol : - 1 cycle : 30 s filtration purge (120 or 240 l/(m^2.h)) 15 min filtration (120 or 240 l/(m^2.h)) 1 min backwash purge (2 x filtration flux) 1 min backwash (2 x filtration flux) - 1 experiment : 14 cycles tableau valves Explication cycles 6/

3.Results Interpretation of the results : 7/

Feed : Sea water (from den Haag and Zeeland) Backwash :demi water and UF permeate Flux : 120 l/(m^2.h) 8/

Feed : Sea water Backwash :demi water and UF permeate Flux : 120 l/(m^2.h) and 240 l/(m^2.h) 9/

Feed : Sea water Backwash :demi water and UF permeate Flux : 240 l/(m^2.h) 10/

Feed : sea water Backwash :demi water and UF permeate Flux :180 l/(m^2.h) 11/

Feed : 2,5 mg/l Alginic acid + 3 mmol NaCl Backwash :demi water and UF permeate Flux :240 l/(m^2.h) 12/

4. Conclusion For sea water, backwashing with demi water is also more efficient than backwashing with UF permeate The higher the filtration flux is, the more fouling we can observe 13/

5. Recommendation More experiments should be conducted for alginic acid solution Tap water should be tested to check whether it can replace demi water for sea water application (cheaper) 14/

Ultrafiltration fouling control Demineralized water backwashing