Uso de macrófitas do bioma Pantanal em soluções baseadas na natureza para o tratamento de água cinza

Abstract

Landscape harmony is a key factor in applying nature-based solutions (NBS) to provide green areas with a crucial role for plants. In the context of this thesis, the plants must also adapt and resist the characteristics of greywater (GW). The aquatic macrophytes are an option, in view of the ornamental potential and possibility of producing bioactive compounds, improving the performance of the systems and enabling the use of biomass to generate byproducts. The Pantanal is rich in aquatic macrophytes and is little explored in terms of studies of bioactive molecules. Thus, first, seven macrophyte species were selected and evaluated for antimicrobial action against nine strains of bacteria. The species Ludwigia lagunae and Polygonum acuminatum were promising, revealing the presence of bioactive compounds in the extracts. Thus, they were selected to evaluate their adaptability and performance in mesocosms irrigated with graywater. Correlation analyses of the PSII photosystem and physico-chemical parameters showed that mesocosms irrigated with GW without nutrient supplementation exhibited stress. Dissolved oxygen values below 3 mg L-1 for L. lagunae and temperature above 27 °C for P. acuminatum were limiting factors for development. Supplementation of AC with nutrients resulted in good growth and performance, with an average of 85% chemical oxygen demand (COD) removal for both. L. lagunae irrigated with GW supplemented with nutrient still showed the best evapotranspiration capacity. Therefore, for a third step, testing two reduced-scale evapotranspiration chamber (CEvaT) configurations, the systems were planted with L. lagunae, received GW, and operated at zero liquid discharge. The different systems did not differ in the removal of COD and surfactant loading, with an average removal of 86% and 94%, respectively. However, it was noted that the difference in area between the systems required greater volumetric feeding and therefore loading for the larger area CEvaTs. Thus, the use of planted CEvaTs, especially with L. lagunae, a species in bioactive compounds, can increase the availability of green areas in urban areas and take advantage of the resource available in GW.