Características hidrodinâmicas de um reator UASB abiótico

Abstract

This work sought to evaluate the hydrodynamic behaviour of an abiotic UASB reactor in bench scale (1 L) through hydrodynamic stimulus-response assays. Methylene blue, eosin Y, lithium chloride, bromocresol green and bromofenol blue were used as tracers to carry out the pulse-type assays. UASB reactor UASB was operated with influent flowrate of 4 L/d (0,166 L/h), hydraulic retention time (HRT) of 6 h and kept at room temperature. Simulations of the hydrodynamic assays were done on the UASB reactor with only water (WR), injection of air in the bottom part of the reactor simulating generation of gases (RWA), spheres of polyacrylamide gel representing the biomass of an anaerobic reactor (RWS) and injection of air and spheres of polyacrylamide gel at the same time (RWAS). Hydraulic retention time, number of complete mixed reactors in series and number of dispersion of the uniparametric models of N-CSTR, low and high dispersion were determined by reading the wavelength by colorimetric methods. Hydraulic efficiency and the anomalies dead zones and short-circuiting were also determined. The results for the reactor RW, RWA, RWS and RWAS were: HRT of 6.2, 6.7, 5.9 and 5.9, respectively; N-CSTR in series of 4, 5, 4 and 4, respectively; D/uL of low dispersion of 0.14, 0.12, 0.17 and 0.13, respectively; D/uL of high dispersion of 0.15, 0.10, 0.11 and 0.09, respectively; volume of dead zones of 19%, 5%, 10% and 2.5%, respectively; short-circuiting of 5.6%, 2.6%, 0.44% and 2.4%, respectively. Statistical analyses Anova and post-hoc test of Tukey indicated statistical difference comparing the three-uniparametric models with major significance for the presence of spheres of polyacrylamide gel (PS).