Badania modelowe skuteczności oczyszczania ścieków w piasku średnim z warstwą wspomagającą z hydro-antracytu
The model investigations of sewage purification were carried out in a medium sand bed with an assisting hydro-anthracite layer with thickness of 0.10 and 0.20 m. It has been observed that the effectiveness of sewage purification related to basic qualitative parameters (total suspended solids – TSS, BOD5, COD, total nitrogen, total phosphorus) is in accordance with the Polish standards on sewage disposal into grounds and surface water. It has been stated that the medium sand soil bed with the 0.20-meter thick assisting hydro-anthracite layer shows higher effectiveness of sewage purification than the 0.10 m thick assisting layer. This application in the medium sand soil bed increased the removal efficiency regarding TSS by 3.1%, total nitrogen by 29.4%, ammonia nitrogen by 1.2% and total phosphorus by 23.0%, and reduction efficiency regarding BOD5 by 1.5% and COD by 11.3% with relation to the 0.10-meter thick assisting hydro-anthracite layer (all percentages – in average). The investigations confirm that the hydro-anthracite with the granulation of 1.8–2.5 mm can be used to assist in removal of nitrogen and phosphorus compounds from sewages