Remoción biológica de materia orgánica, nitrógeno y fósforo en un sistema tipo anaerobio-anóxico-aerobio.

Abstract

Experimental results from a series of biological unitary processes for the simultaneous removal of organic matter (OM), nitrogen (N) and phosphorus (P) are shown in this study. A synthetic substrate similar to a domestic wastewater of average concentration was used. The experimental development was made using an A2O system (anoxic-aerobic-anaerobic) performed in two phases. The preliminary stage lasted 60 days and included, besides the acclimatization of the biological sludge, the examination of polyurethane foam as a support medium in the aerobic phase. In the secondary stage, the stability was rapidly reached; this phase lasted 280 more days; a significant increase of the removal efficiencies was observed to be close to 92.5 % in organic matter, 87.7 % in nitrogen, and 83.5 % in phosphorus. Parameters such as dissolved oxygen (DO) and oxide reduction potential (ORP) were permanently monitored and maintained in values according to the requirements of the processes in each reactor. On the other hand, pH was measured to be higher than 7.2 units, ensuring the viability of the nitrification-denitrification processes. A hydraulic study using tracers was developed in order to find out the effect of the support medium on the hydraulic regimen of the aerobic reactor.