(19)

(11)

EP 0 831 962 A1

(12)

(43) Date of publication: 01.04.1998 Bulletin 1998/14 (21) Application number: 96917589.0 (22) Date of filing: 10.06.1996

(51) International Patent Classification (IPC):  B01D 63/ 00( . ) B01D 63/ 04( . ) B01D 65/ 00( . ) B01D 63/ 02( . ) B01D 63/ 06( . ) B01D 65/ 10( . ) (86) International application number: PCT/GB1996/001395 (87) International publication number: WO 1996/041676 (27.12.1996 Gazette 1997/04)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI NL PT SE (30) Priority: 10.06.1995 GB 19950011842 (71) Applicant: United Utilities PLC Great Sankey, Warrington WA5 3LW (GB)	(72) Inventors: FINLAYSON, Gregory Kensington, VIC 3031 (AU) FORBES, Mark, Lewis East Ivanhoe, VIC 3079 (AU) GALLAGHER, Paul, Martin Warrington, Cheshire WA5 3DF (GB) DUKES, Simon, Paul Warrington, Cheshire WA5 5RZ (GB) (74) Representative: Allman, Peter John, et al  MARKS & CLERK, Sussex House, 83-85 Mosley Street Manchester M2 3LG Manchester M2 3LG (GB)