Abstract: A method and apparatus for recovering fine solids from a liquid feed suspension is disclosed. The apparatus has an operating cycle including a concentration part of the cycle in which solids present in the feed suspension are concentrated and a backwash part of the cycle in which supply of feed suspension to the concentrator is interrupted, the concentrator comprises a shell (11), and a plurality of elastic, hollow, microporous, polymer fibers (12) being fixed at their ends within the shell (11). Pressurized feed suspension is supplied to the outside of the fibers during said concentration part of the cycle and the filtrate may be withdrawn from the fiber lumens during the operating cycle. During the backwash cycle the concentration part of the cycle is terminated by ceasing supply of feed to said exterior surface of the fibers (12). The shell (11) is then sealed and the remaining filtrate removed from the lumens.

Abstract: A method and apparatus for determining the fouling effect of a feedstream on a filter having known characteristics disclosed. The method comprises passing the feedstream through a filter (5) having known characteristics; determining the change in resistance to flow of the feedstream across the filter, either continuously or over a number of time intervals and from this data, calculating a feed fouling index (FFI) representative of the fouling characteristics of the feedstream with respect to the filter. A method and apparatus for monitoring the operation of a filtration system is also disclosed the method comprising sampling system parameter values at selected locations within the filtration system at a predetermined sampling rate; generating a parameter profile characteristic from the sampled parameter values at predetermined intervals of time; and analysing the parameter profile characteristic to determine correct operation of the filtration system.

Abstract: A failed hollow fiber is located in a membrane filtration module by supplying a gas under pressure to the space between fibers and shell, wetting the ends of fibers, and monitoring the ends of the fibers for bubble formation.

Abstract: An electrochemical cell comprises a porous membrane (8) of electrically insulating composition, the membrane having pores (not illustrated) communicating from one side of the membrane to another, a working electrode (5) disposed on one side and a counter or pseudo-reference electrode (7) disposed on the other side. A target area (11) of one electrode is liquid permeable and extends over the surface of membrane (8) without blocking underlying pores of the membrane. Optional insulating layers (9,10) cover the electrodes (5,7) and opening defines the target area (11). Preferably, the porous membrane is impregnated with reagents, for example GOD/Ferricyanide.