Sistema híbrido para remoção biológica de nitrogênio de esgoto sanitário

Abstract

Combining anaerobic and aerobic processes in wastewater treatment systems have been considered viable alternatives technically-economically than traditional systems because they have higher nutrient removal , using this way compact systems , low cost - effective and easy maintenance and operation. Since then, Brazilian law regarding the release of effluents into water bodies. In this study, studies were developed as a treatment system combining anaerobic / anoxic ( An/Ax ) followed by aerobic reactor with immobilized support medium (RAMSI) , seeking to produce effluent with low concentrations of organic material and nutrients and produce less sludge excess. The experiment was conducted in two phases. The first phase consisted of combined system anaerobic / anoxic (An/Ax) followed by aerobic reactor of immobilized support medium (synthetic polyurethane sponge) submerged immobilized (RAMSI) operated under batch recirculation . In the second, respirometric tests were performed as a tool to assess the biodegradability of activated sludge lysate through techniques induced cell lysis : acid-base reaction , microwave , thermal and mechanical action. The combined system removed efficiently carbonaceous material (92%, SST (98%), SSV (97%), NTK (93%) and N- NH 4 - (96 %). Producing effluent with average concentrations of nitrite and nitrate, respectively 0.04 mg N - NO 2 - .L -1 and 0.65 mg N-NO 3 - .L - 1 . Through the bullet mass is found a bacterial growth designed for the consumption and removal of substrate (organic fraction) and the nitrification followed by denitrification (nitrogen fraction). Regarding the quantification of biomass present in the reactor An/Ax and RAMSI, found RAMSI showed that the highest concentration of SSV (12766) mg.L and COD (10,878 mg L -1 ) that An/Ax reactor, associating this result in the biofilm support medium (polyurethane foam) inserted inside the reactor. Results obtained through respirometric tests found that the concentration of sludge presented ground rapidly biodegradable material superior to others lysates sludge.