NOVELTY - A sewage treatment system consists of wastewater source, septic tank (11), multi-chamber ion-exchange bioreactor and drain field (15). The septic tank has an untreated-wastewater input to produce a clarified sewage effluent. The multi-chamber ion exchange bioreactor has an input connected to output from septic tank for receiving sewage effluent, anaerobic treatment chamber containing anaerobic bacteria, and ion-exchange chambers for removing nitrogen compounds from effluent. The drain field is connected to the output of bioreactor for percolating treated effluent into the soil.    USE - System is used for treating sewage wastewater and producing nitrogen compounds (claimed) e.g. nitrates, ammonia and organic nitrogen compound used as fertilizer and soil-enriching material.    ADVANTAGE - The system effectively removes inorganic nitrogen contaminants organic nitrogen from wastewater. The treated wastewater has excellent cation-exchange capacity and water-retention capacity with respect to soil.    DETAILED DESCRIPTION - A sewage treatment system consists of wastewater source, septic tank, multi-chamber ion exchange bioreactor and drain field. The septic tank has an untreated wastewater input for reducing solids to produce a clarified sewage effluent in an output. The multi-chamber ion exchange bioreactor has an input connected to output from septic tank for receiving the sewage effluent, anaerobic treatment chamber having a solid blanket containing anaerobic bacteria, and ion-exchange chambers for forming serpentine passage having upflow chamber and downflow chamber for removing nitrogen compounds from effluent passing through anaerobic treatment chamber to an output. The drain field is connected to the output of bioreactor for percolating treated effluent into the soil. The nitrogen compounds are captured in the bioreactor for reuse. An INDEPENDENT CLAIM is included for method of treating sewage.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a septic tank sewage treatment system.    Building (10)    Septic tank (11)    Sewage line (12)    Multi-chamber nitrogen removal module (13)    Output line (14)    Drain field (15)