Abstract: Microbial activity in an aqueous medium is measured in a bioelectrochemical cell in which the working electrode comprises an electrically conductive carbon-bearing porous material; suitably a graphitized carbon felt or cloth. This enhances the BEC response by increasing the surface area and by absorbing microbes onto the surface; and the electrode material can also be used to preconcentrate the microbes prior to use as an electrode in the cell.

Abstract: 1,4-Benzoquinone can act as a mediator of electron transfer in bioelectrochemical cells for measuring microbiological activity in a sample. In combination with ferricyanide it can provide a surprisingly high level of mediator activity with many microorganisms, and a more even response when the sample may contain a mixture of microorganisms.

Abstract: A method of filtering utilizes a filtering apparatus having a filter member presenting a plurality of flow paths therethrough of a form to retain at least a portion of the material to be extracted the method comprising the steps of passing a stream of fluid to be filtered in a forward direction from an inlet through the filter member, moving the filter member out of the stream of fluid, changing the geometry of the filter member under gravity, e.g. by inverting the filter member, to assist in removal of extracted material from the filter member.