Abstract: A filter system (10) is disclosed that includes a filter assembly (12) and input/output hardware (14). The filter assembly includes a housing (16) and cap (18) that cooperatively support a prefilter (20) and main filter (22) in a fluid flow path. Fluid flow through the filter assembly occurs radially through the prefilter and axially or radially through the main filter. The main filter includes an alkaline leaching agent to raise the pH of fluid flowing therethrough to, for example, between 8 and 10. A method is also disclosed for evaluating the effectiveness of the filter system in reducing a select contaminant from the fluid by evaluating the effectiveness of the filter system in raising the fluid's pH.

Abstract: A method for treating water removed from the ground is disclosed. The treatment reduces the content of noxious sulfur-containing impurities therein before the water is supplied to an associated water system. The method involves the steps of spraying the water to be treated in the upper portion of a standpipe, entraining air with the water which is sprayed in the upper portion of the standpipe, and maintaining a required water level in the standpipe. Spraying the water to be treated in the standpipe causes a flow of water from within the standpipe through a bed of a catalyst for the oxidation of sulfur and sulfur-containing moieties to sulfate anions and from the catalyst bed to the associated water system. The water level maintained in the standpipe is that required to enable the flow of water therefrom through the catalyst bed to the associated water system.

Abstract: The present invention relates to a reactor for biological purification of pollutant-containing water in a closed vessel by means of loop operation. This vessel contains, disposed vertically and concentrically with respect to its jacket and to each other, an insertable pipe that is open at both ends, into which a nozzle projects for the purpose of supplying the water-gas-biomass mixture to be purified, and a guide pipe that is open at both ends and that forms an inner annulus with the internal insertable pipe and an outer annulus with the reactor jacket. This guide pipe projects above and below the ends of the insertable pipe. A deflector plate is mounted below the insertable pipe but inside the guide pipe, so that part of the biomass-water mixture is deflected back into the inner annulus. A conically shaped sedimentation chamber is disposed in the lower part of the reactor.