초록 ▼

A method of treating sewage is disclosed that is particularly suitable for one or a small group of residential dwellings in environmentally sensitive areas. The raw sewage is flowed first into an aerobic first cell where it is aerated and forced into a highly aerobic condition where aerobic bacteria

A method of treating sewage is disclosed that is particularly suitable for one or a small group of residential dwellings in environmentally sensitive areas. The raw sewage is flowed first into an aerobic first cell where it is aerated and forced into a highly aerobic condition where aerobic bacteria grow and consume phosphorus in a vigorous life cycle and then die. Substantial primary unloading of B.O.D., T.S.S., coliform, and phosphorous is accomplished in this first cell. The fluid from the first cell overflows into a second cell where additional sedimentary clarification occurs and it goes anaerobic. A third cell has an upwelling flow through a porous medium substrate where anaerobic bacteria converts nitrogen in nitrates and nitrites to nitrogen gas, and the fluid then flows into a fourth holding cell. The effluent in the holding cell can then be flowed intermittently through a sand filter that has a bed of dolemite for final removal of residual phosphorus before it flows into a drain field. Alum and methanol can be added to the raw sewage to, respectively, enhance initial flocculation and sedimentation in the first cell and to support anaerobic bacteria in the third cell.

대표청구항 ▼

The method of treating sewage, comprising the steps of: flowing raw influent sewage into a first cell; and, before allowing the raw influent sewage to go into an anaerobic condition, aerating the raw sewage in the first cell to force and maintain it into an even more highly aerobic condition, and al

The method of treating sewage, comprising the steps of: flowing raw influent sewage into a first cell; and, before allowing the raw influent sewage to go into an anaerobic condition, aerating the raw sewage in the first cell to force and maintain it into an even more highly aerobic condition, and allowing sufficient dwell time therein for aerobic bacteria to grow and consume phosphorus and then die, for B.O.D., T.S.S., and coliform bacteria to form organic precipitates, and for the solids and precipitates to substantially settle out of the liquid in said first cell; overflowing the remaining aerobic liquid and any remaining unsettled solids from said first cell into a second cell and allowing sufficient essentially stagnant dwell time in said second cell for substantially all of the remaining solids to settle out of the liquid in said second cell and for the sewage to undergo a conversion from aerobic to substantially anaerobic condition in said second cell; overflowing the anaerobic liquid from the second cell into the bottom portion of a third cell, and flowing the anaerobic liquid upwardly through a porous media substrate in said third cell having anaerobic microorganisms growing on the surfaces and in the pores of the substrate and allowing sufficient dwell time in the third cell for the anaerobic microoganisms therein the convert most of the nitrogen in nitrates and nitrites in the liquid to nitrogen gas; overflowing the effluent liquid from the third cell into a fourth cell; and intermittently removing accumulated effluent liquid from the fourth cell.