Remoção de alquilbenzeno linear sulfonato em esgoto doméstico tratado em reator UASB e lagoa de polimento

Abstract

We evaluated the removal of linear alquilbenzene sulfonate (LAS) in a sewage treatment plant (WWTP) with a UASB reactor and a polishing pond during two seasonal periods, dry and rainy. The removal was also evaluated in one of the eight cells of the UASB reactor (810 m3). In this cell, the removal was predominantly by adsorption, of 68±52 and 0% for the dry and rainy seasons, respectively. The total removal efficiency of LAS in the WWTP was between 80±15 and 98±3%, considering the two seasonal periods. The LAS concentration in the polishing pond effluent was between 0.1±0.3 and 0.6±0.3 mg.L-1. Therefore, the quality of the final effluent, in terms of LAS, was very satisfactory, with values lower than those defined by the Brazilian legislation (<0.5 mg L-1 of LAS) of CONAMA, for substances reacting with the methylene blue, when the receiving water body is within the classes 1 to 3.