Desenvolvimento de macrófitas e desempenho de sistemas alagados construídos tratando esgoto bruto

Abstract

In Brazil, approximately 50% of generated sewage is discharged untreated and Constructed Wetlands (CWs) offer a low-cost and highly efficient alternative for pollutant removal in small populations. When ornamental species are introduced into these systems, they can be considered filter gardens, enhancing well-being to surrounding population. This study aimed to evaluate the performance of the species Thaumatophyllum uliginosum, Echinodorus grandiflorus and Cyperus alternifolius in free water surface constructed wetland treating domestic sewage. The experiment consisted in seven treatments with 5 replications, four of them in CWs, including the control system without plants, and the three species in pots with substrate watered with water. Chemical analysis for efluente and species and biometric analisys. Statistical analysis was performed using the SISVAR statistical program. CWs efficiency was assessed over five months and the maximum removal values, considering evapotranspired volume and respective species, were as follows: 98.8% COD with T. uliginosum; 99.8% BOD with E. grandiflorus; for E. coli (6 logarithmic units), phosphorus (98.7%); Ammonium N (98.9%); and chlorides (94.5%) with C. alternifolius and Settable solids (90%) with all CWs. The CWs met state legislative requirements for average physicochemical parameters. Under the evaluated experimental conditions, all CWs species exhibited significant development submerged in sewage, with notable biometric parameters and nutriente accumulation, particularly in C. alternifolius and T. uliginosum. In conclusion, the studied species have potential for implementation in full-scale CWs, providing not only sewage treatment functionality but also the benefits of landscaping in a filter Garden.