Balanço de sólidos e nutrientes em sistema de alagado construído para tratamento de resíduos de fossa e tanque séptico

Resumo

Cesspits and septic tanks wastes (CSTW) should be treated prior to disposal in the environment. The use of constructed wetland systems (CWS's) emerges as an alternative technology, simple and low cost, efficient and with great potential for practical use. Thus, this work aimed to study the flow of solids and nutrients in a CWS for treating CSTW. Two tanks were built and filled with overlapping layers of gravel and sand for application and treatment of CSTW. A tank was grown by the plant species Vetiver Grass (Vetiveria zizanioides) and the other worked as control. Physicochemical analyses of crude residue and treated both tanks were made to calculate the efficiency of the treatment, which took into account the evapotranspiration rates of the tanks. The vegetated tank was more efficient in removing total solids, settleable and fixed solids, and total phosphorus and ammonia nitrogen. Both tanks showed variations in their efficiency, mainly due to varying application rates. Due to the high volume of ammonia, the CWS was not enough to compliance with environmental legislation, requiring further treatment of their effluent. A high accumulation of sludge on the surface of both systems with higher moisture in the tank vegetated. For the operation of these systems, it is recommended that the study of optimum rates of application.

Descrição

Palavras-chave

Zona de raízes, Balanço de massa, Fitorremediação, Root zone, Phytoremediation, Mass budget

Citação

SILVA JR., Édio et al. Balanço de sólidos e nutrientes em sistema de alagado construído para tratamento de resíduos de fossa e tanque séptico. Enciclopédia Biosfera, Jandaia, v. 9, n. 17, p. 3281-3291, 2013.