Remoção de surfactantes em sistema baseado na natureza tratando água cinza

Abstract

Constructed wetlands are low cost systems used worldwide to treat wastewater. These systems are based on natural ecosystems and treatment process involving complex interactions between soil, water, plants, microorganisms and predominant flow patterns. Studies demonstrate the efficiency of these systems in removing organic matter, solids, nitrogen, phosphorus and bacteria. On the other hand, there is little information on the fate of organic pollutants, such as linear surfactant alkylbenzene (LAS), used in detergents, worldwide, and, as such, is a general component of domestic wastewater. Conventional methods used in the treatment of these water, such as anaerobic biological reactors, stabilization ponds present difficulties in removing these pollutants. In this work, it is possible evaluate an evapotranspiration and graywater treatment system (EvaTAC), treating this water of a pilot system, simulating a family routine on a real scale on removal of LAS. These research achieved removal efficiency that meets states standards CECA 036/2012 and federal CONAMA 430/2011, where COD removal reached 56% and the system’s BOD output (38 to 42 mg.L-1 ) was less than 120 mg.L-1 (standard release legislation), even with a high applied organic load, being 67,7 gDQO.m-2.d-1 for the first phase and e 19,2 gDQO.m-2.d-1 for the second. The legislation mentioned above does not establish limits for release LAS into environment. In this work reached 45% of LAS removal, being average value output of system 22.3±11,1 mg.L-1 in the first phase and 17.8 ±6,8 mg.L-1 in the second. Although this compact system has not achieved a great deal of pollutant removal, it can be used in small communities and the effluent can be used for non-potable purposes.