Influência da carga de nutrientes e da espécie cultivada na remoção de K, Na, Cu e Zn da água residuária da suinocultura tratada em sistemas alagados construídos

Abstract

This study aimed to evaluate the influence of nutrient loading and species cultivated in removing K, Na, Cu and Zn from swine wastewater treated in constructed wetlands (SACs). The experiment consisted of eight SACs, built on a pilot scale. SAC 3, SAC 5, SAC 7 and SAC 9 were planted with Tifton-85 bermudagrass (Cynodon spp.) and SAC 2, SAC 4, SAC 6 and SAC 8 were planted with cattail (Typha latifolia). The difference in load was made by applying different inflows to the SACs, corresponding to loading rates of potassium (TCK), sodium (TCNA), copper (TCCu) and zinc (TCZn) of 21.6, 15.2, 0.017 and 0.140 (SAC 2 and SAC 3), 43.4, 30.6, 0.035 and 0.281 (SAC 4 and SAC 5), 61.1, 43.0, 0.05 and 0.395 (SAC6 and SAC7), and 74.4; 52.4, 0.060 and 0.481 kg ha -1 d -1 (SAC8 and SAC 9). The variables were statistically evaluated in a 2 x 4 factorial (2 species and 4 rates of nutrient loading) in a randomized block design. It has been found that neither the applied load nor the type of species cultivated influenced the removal of Na, Cu and Zn from the SACs, except for K, for which the load applied influenced the removal of this constituent.