NOVELTY - The anode comprises electrode elements (20) adapted to be received within the microbial fuel cell. The electrode element is made of a polymer material having an electrically conductive material that is interspersed with the polymer material. The electrically conductive material comprises a powder or a granular substance that is interspersed with the polymer matrix. The powder or granular substance has a mean particle size of 200-300 nm. The electrode elements comprise 1-5 wt.% of electrically conductive material to polymer material.    USE - The anode is useful for a microbial fuel cell, which is useful for treating water, for generating bio-gas, for collecting nitrogen based compound such as nitrates contained in waste water (all claimed), for reducing the contamination level or organic content of the waste water before it is placed in the drain and for producing biomass used as fertilizer, where the bio-gas is useful as fuel.    ADVANTAGE - The anode can be economically manufactured, stimulates proton removal from microbes, enhances microbial growth, encourages movement of organic and nitrogen compounds to migrate to the surface, and facilitates microbial harvesting.    DETAILED DESCRIPTION - The anode comprises electrode elements (20) adapted to be received within the microbial fuel cell. The electrode element is made of a polymer material having an electrically conductive material that is interspersed with the polymer material. The electrically conductive material comprises a powder or a granular substance that is interspersed with the polymer matrix. The powder or granular substance has a mean particle size of 200-300 nm. The electrode elements comprise 1-5 wt.% of electrically conductive material to polymer material. The electrode elements are held within a cage (30), which is made of non-metallic material and an insulating material. The electrode elements comprise an external frame portion, and an internal structure that extends within the frame portion. The external frame portion includes apertures such that, in use, electrolyte passes over and/or microorganisms gather on the external frame portion and the internal structure. The external frame portion has a tubular structure having apertures. The internal structure comprises struts that extend along diameters of the tubular frame portion. A surface of each electrode element is rough. The polymer material includes a water treatment agent that is adapted to treat pollutants in the water or adapted to be released on application of an electric current to the anode. The water treatment agent is loaded onto the carbon black on the surface of the electrodes such that it binds to polluting elements such as sulfur based compound, heavy metals or halogenated compounds. The water treatment agent comprises a porous medium based compound such as activated carbon, an immobilized biocatalyst including enzymes, or a heterogeneous catalyst for removal of toxic compounds. INDEPENDENT CLAIMS are included for:    (1) a method of manufacturing an anode for a microbial fuel cell;    (2) a cathode for a microbial fuel cell;    (3) a method of manufacturing a cathode for a microbial fuel cell;    (4) a method of coating an electrode with a catalyst;    (5) a microbial fuel cell;    (6) a method of treating water using the microbial fuel cell;    (7) a method of generating bio-gas using the microbial fuel cell; and    (8) a method of collecting nitrogen based compounds such as nitrates contained in waste water using the microbial fuel cell.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic side view of an anode.    Electrode element (20)    Cage (30)    Lid. (31)