Remoção de matéria carbonácea, nitrogenada e fosforada de efluente aeróbio por ozonização

Abstract

The increased interest in the use of ozone for the treatment is due to its high oxidative potential, especially organic compounds with low biodegradability. In the present study evaluated the efficiency of the ozonation process, as post-treatment, the removal of carbonaceous matter, nitrogenous and phosphorated an aerobic effluent. For this it prepared an experimental apparatus containing air compressor, flowmeter, ozone generator and ozonation column (6 L). The apparatus operated in batch, was fed aerobic effluent of an anaerobic reactor. The effluent was transferred to the column in its natural pH, the pH's adjusted to 3.0 and 10.0 and were taken aliquots of 50 mL every 15 minutes from the experimental process. The effluent received average concentration of 0.83 mgO3.h-1 generated by the generator over 60 min, 120 min and 180 min. The parameters analyzed were: temperature, pH, turbidity, chemical oxygen demand (COD), TNK, nitrate, nitrite, phosphorus, residual ozone and ozone consumed. In this study, the change in pH during the ozonation process was small, in the range 6.19 to 6.92 for the effluent in its natural pH, 3.25 to 3.85 pH adjusted to 3.0 and 9, 35 to 10.10 for pH adjusted to 10.0. The temperature did not affect the analysis and was between 15 to 26 ° C, which was temperature variation months of the study. The average removal efficiencies of organic matter in terms of COD were low and varied. The nitrate concentration was parameter which saw greater removal efficiency especially in pH 3.0. The nitrite parameters, TKN and phosphorus underwent no significant changes throughout the trials This research found that during the first 15 minutes of ozonation, the off-gas has an increasing, indicating that the start of the tests had the highest concentration of material with which ozone and hydroxyl radicals were reacting. Throughout this work it can be observed that the ozonization is efficient results in some parameters and others in inefficient oxidation effluent at all pH variations.