Method and equipment for a wrap-around upflow submerged anaerobic filter for sewage

Claim 1

Equipment for the treatment of sewage comprising: a septic tank having an inlet for raw sewage and an outlet for effluent, an anaerobic filter composed of a bed of surface contact material including void spaces for filamentous zoogloea growth laterally surrounding said septic tank, the inner boundary of said anaerobic filter being defined by said septic tank and the outer boundary being defined by a means for retaining the surrounding earth which prevents fine aggregates in the earth from entering said anaerobic filter, an effluent discharge line connecting said outlet to a perforated distribution line outlet for distributing said effluent into said anaerobic filter at approximately the lowest elevation in said anaerobic filter, a perforated discharge riser positioned diametrically opposite said distribution line outlet for collecting effluent which has passed through the filter, overlow weirs positioned on said effluent discharge line and said discharge riser for bypassing the filter and directing said effluent from said outlet to said discharge riser, said overflow weirs being connected to a vent system for venting the gaseous products produced in said anaerobic filter, and means for connecting said discharge riser to a final treatment system.

Claim 9

A method for treatment of effluent discharged from a septic tank prior to delivery of the effluent to the final treatment phase comprising the steps of: directing said effluent from said septic tank through an effluent discharge line into a perforated distribution line outlet at approximately the lowest elevation in an upflow anaerobic filter laterally surrounding said septic tank, said anaerobic filter composed of a bed of surface contact material including void spaces for filamentous zoogloea growth, the inner boundary of said anaerobic filter being defined by said septic tank, and the outer boundary being defined by a means for retaining the surrounding earth which prevents fine aggregates in the earth from entering the filter, passing said effluent upwardly and horizontally through said void spaces to contact said filamentous zoogloea growth, collecting said effluent which has passed through the filter in a perforated discharge riser positioned diametrically opposite said distribution line outlet to maximize the detension time of said effluent in the filter, directing the collected effluent to a final treatment phase, continuously venting gaseous products produced in said anaerobic filter through overflow weirs positioned on said effluent discharge line and said discharge riser into a vent system, bypassing said anaerobic filter by directing said effluent from said septic tank through said overflow weirs into said discharge riser when the filter becomes clogged, and washing the filter to restore the flow of said effluent through the filter.

Claim 10

A method for treatment of effluent discharged from a septic tank prior to delivery of the effluent to the final treatment phase comprising the steps of: directing said effluent from said septic tank through an effluent discharge line into a perforated distribution line outlet at approximately the lowest elevation in an upflow anaerobic filter laterally surrounding said septic tank, said anaerobic filter composed of a bed of surface contact material including void spaces for filamentous zoogloea growth, the inner boundary of said anaerobic filter being defined by said septic tank, and the outer boundary being defined by a means for retaining the surrounding earth which prevents fine aggregates in the earth from entering the filter, passing said effluent upwardly and horizontally through said void spaces to contact said filamentous zoogloea growth, collecting said effluent which has passed through the filter in a perforated discharge riser positioned diametrically opposite said distribution line outlet to maximize the detension time of said effluent in the filter, directing the collected effluent to a final treatment phase, continuously venting gaseous products produced in said anaerobic filter through overflow weirs positioned on said effluent discharge line and said discharge riser into a vent system, bypassing said anaerobic filter by directing said effluent from said septic tank through said overflow weirs into said discharge riser when the filter becomes clogged, and washing the filter to restore the flow of said effluent through the filter.

Claim 12

A method for treatment of sewage as claimed in 9 comprising the periodic restoration of the anaerobic filter by the use of organic or inorganic chemicals.