Sistema de bancada de flotação por ar dissolvido e filtração-adsortiva para tratamento de efluentes de reatores anaeróbios

Abstract

This essay is supposed to evaluate the post-treatment of UASB reactor´s effluent using flotation followed by adsorption filtration using zeolite. The anaerobic effluent that was used in this essay was the one obtained at the ETE Zona Norte´s UASB reactor, located in Londrina. The tests took place in the sanitary laboratory at UTFPR Londrina. The adsorption filters were placed right after the flotation test. The adsorption beds were made with 20 mm diameter plastic, configuring a fixed bed model with descendent flow. There were three columns in parallel. The fixed parameters were: Gmr = 800 s-1; Tmr = 15 s; Gfloc = 80 s-1; Tfloc = 10 min; Psat = 5 Bar; R = 20 %; Tci = 30 s e Vf = 16 cm.min-1, the coagulant was 90 mg/L of Al2O3 in the first step. In the second step it was 9 mg/L of Al2O3. All the others parameters were the same. On the filtration, the surface application rate varied from 200 to 300 m3/m2d. The effluente was analized in the UASB reactor, in the end of the flotation and in the end of the adsorption filtration. The best results were obtained with the dosage from 90 mg/L of Al2O3. The efficiency was 98% for residual turbidity, 97% for apparent color, 90% for QOD, 100% for ammoniacal nitrogen, 89% for total solids, 81% for fixed total solids, and 96% for volatile total solids. It is possible to conclude that the system is a good option for tertiary treatment of wastewater. The zeolite which is commercialized shows that it has a good ammoniacal nitrogen removal capacity.