You are here:
LONG TERM RECHARGE OF TRICKLING FILTER EFFLUENT INTO SAND
Citation:
Aulenbach, D. LONG TERM RECHARGE OF TRICKLING FILTER EFFLUENT INTO SAND. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-79/068.
Description:
The rapid infiltration of trickling filter effluent onto natural delta sand beds at the Lake George Village Sewage Treatment Plant has been shown to produce the equivalent of tertiary treatment to the domestic wastewater since 1939 with no indication of exhaustion of the purification capacity. Most of the purification took place in the top 10 m of the sand. BOD, COD, alkylbenzenesulfonates, total and fecal coliforms, and phosphates were essentially completely removed in the sand system. Ammonia and organic nitrogen were converted to nitrates, some of which were removed under reducing conditions. Vertical velocities in the sand were measured between 0.6 m/day and 2.5 m/day. Horizontal velocities varied between 3 m/day and 12 m/day. Allowing weeds to grow on the sand beds increased the infiltration rate when the depth of liquid on the bed exceeded 0.3 m, but decreased the infiltration rate at shallower depths. A rapid sand infiltration system is recommended as a suitable means of providing tertiary treatment to domestic wastewater.