AVALIAÇÃO DE SISTEMA HÍBRIDO DE WETLANDS CONSTRUÍDAS COM E SEM RECIRCULAÇÃO

Abstract

The use of constructed wetlands (WCs) in wastewater treatment is not widespread in Brazil. These systems consist of an eco-technological alternative with potential use for treatment of domestic, industrial, and agricultural wastewater. In Brazil, the total sewage service rate is only 54.95%, considering the municipalities served with water, then a large part of the Brazilian population does not have adequate sanitary sewage management. That elucidates the growing studies that are being developed to implement decentralized treatment systems capable of serving mainly small towns and more distant communities. The proposal for recirculation arises to reach a higher level in the treatment, increasing the effluent detention time to reduce the organic matter concentration. In this scenario, this experimental research, even treating low volumes, could open paths for the diffusion of decentralized wastewater treatment systems in recirculation in Brazil, prioritizing the search for solutions that are highly efficient, replicable and had low cost. In this work, a review of applied literature was carried out, based on data from the CAPES Periodicals portal, with scientific articles that evaluated the WCs performance to remove organic matter. From this search, 15 articles were selected referring to research carried out in the last 10 years. The systems evaluated in the recirculation phase showed efficiencies ranging between 34-98% and 29-98% to remove BOD and COD, respectively. Among the hybrid systems evaluated, WC-FSSV presented the best results to remove organic matter in most of the researches. In the studies evaluated, it was also evident that the presence of vegetation is important to remove pollutants in WCs, especially organic matter, where removal efficiencies were higher in systems with vegetation. Regarding the substrate, in 60% of the studies the authors used gravel as substrate. In short, it is concluded that the use of WCs, both vertical and horizontal flow, as well as coupled and hybrid systems, showed high potential to remove organic matter.