@article{Martins Ferreira Gaspar_Passos Piveli_Alem Sobrinho_2009, title={Remoção de nutrientes em sistemas de lodo ativado recebendo esgoto pré-tratado em reator UASB}, volume={1}, url={https://www.revistas.unam.mx/index.php/aidis/article/view/14368}, abstractNote={This paper presents and discusses operational results of a pilot UASB reactor followed by an activated sludge unit for domestic wastewater, aiming the removal of nitrogen and phosphorus. Four experiments were run, maintaining the sludge age of approximately 10 days in all the experimental stages. In order to evaluate the phosphorus removal 4 experiments were carried out with the following operational conditions: STAGE 1) without addition of coagulant or polymer; STAGE 2) addition of ferric chloride (80 mg FeCl3/L), without polymer addition; STAGE 3) addition of ferric chloride (80 mg FeCl3/L), and of 1mg/L cationic polymer; and STAGE 4) ) addition of ferric chloride (150 mg FeCl3/L), without polymer addition. The following conclusions were obtained: A) The activated sludge process, treating the effluent of an UASB reactor, is not efficient for nitrogen removal, due to the low amount of organic matter, needed by the organisms that carry out to denitrification; B) As far as ammonia removal is concerned, the activated sludge process is effective, as average removal efficiencies above 95% were reached; C) The use of ferric chloride for the physical‐chemical removal of phosphorus was shown effective only for high relations Fe/Total P. Fe/Total P average relations ranged from 2.0 to 5.6 in the operational stages. With Fe/Total P relations from 1.5 to 2.1:1 and 2.3 to 2,8:1 the expected phosphorus removals in the order of 85% and 95%, respectively, did not occur. The average efficiencies of total phosphorus removal varied from 63 to 94% in the operational stages; D) The average relations of MLVSS/MLSS varied from 0.7 to 0.5 in the operational stages; the reduction of this relation is due to the generation of "chemical sludge"; and E) The system was shown efficient for the removal of organic matter. The average efficiencies of organic matter removal varied from 73 to 87% for total COD, in the operational stages.}, number={2}, journal={Revista AIDIS de ingeniería y ciencias ambientales: Investigación, desarrollo y práctica}, author={Martins Ferreira Gaspar, Patricia and Passos Piveli, Roque and Alem Sobrinho, Pedro}, year={2009}, month={nov.} }