(19)

(11)

EP 1 251 924 A1

(12)

(43) Date of publication: 30.10.2002 Bulletin 2002/44 (21) Application number: 01902479.3 (22) Date of filing: 26.01.2001

(51) International Patent Classification (IPC)7: B01D 21/24, B01D 21/00, C02F 1/40 (86) International application number: PCT/GB0100/309 (87) International publication number: WO 0105/4789 (02.08.2001 Gazette 2001/31)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR Designated Extension States: AL LT LV MK RO SI (30) Priority: 28.01.2000 GB 0002089 (71) Applicant: Thames Water Utilities Limited Reading,Berkshire RG2 0JN (GB)	(72) Inventor: WILLIAMS, IanThames Water Utilities Ltd. Reading, Berks RG2 0J N (GB) (74) Representative: Jacob, Reuben Ellis  Edward Evans BarkerClifford's Inn,Fetter Lane London EC4A 1BZ London EC4A 1BZ (GB)