This study applies the single continuous-inflow batch system to treat domestic wastewater directly by the procedures of continuous-inflow, intermittent aeration, and intermittent-outflow, In four runs, varied influent rate, organic loading, cycles per day and the time of aeration/non-aeration phase per cycle used to determine the treatment characteristics of the system. In the experimental results, the system showed good efficiency of BOD, nitrogen and phosphorus removal simultaneously under the conditions of appropriate operation parameters. The developed vertical up-downward decanter and baffle with holes are modified from the conventional single batch system and can minimize the short-circuit as the inflow is continuous and make the effluent qualities stable.
