Patent ID: 9133044
Filing Date: 2015-09-15
Classification: C02F

Abstract:
1. A reactor tank for the biological treatment of feedwater, said reactor tank comprising: an upper, aerobic reaction zone and a lower anoxic/anaerobic reaction zone, wherein the upper, aerobic reaction zone contains a bed that is maintained in place by an upper screen and a lower screen, one or more feedwater inlets in the lower anoxic/anaerobic reaction zone, one or more effluent outlets in the upper, aerobic reaction zone, wherein the feedwater is subject to treatment within both the lower anoxic/anaerobic reaction zone and the upper, aerobic reaction zone, said upper, aerobic reaction zone being provided with aerated biofilm media for forming substrates for growth and release of biological matter, said lower anoxic/anaerobic reaction zone contains an activated sludge or biofilm media, wherein the sludge volume changes with purging of the sludge, and a separator structure arranged between the upper, aerobic reaction zone and the lower anoxic/anaerobic reaction zone, wherein the separator structure permits the upwards passage of fluids from the lower anoxic/anaerobic reaction zone to the upper, aerobic reaction zone, and prevents oxygen from entering the lower anoxic/anaerobic reaction zone, wherein said separator structure further has a generally inclined upper surface that guides said released biological matter from the upper, aerobic reaction zone to the lower anoxic/anaerobic reaction zone, where said biological matter is further processed and sludge is collected and removed only from the lower anoxic/anaerobic reaction zone through a sludge outlet.