Avaliação de sistema wetlands construída no tratamento de efluentes utilizando a macrófita crinum americanum

Abstract

The low level of sanitary sewage treatment and its influence on public health poses challenges to public agencies to find efficient techniques for the treatment of this type of effluent. The use of artificial wetlands has been highly widespread in the world, been characterized as an efficient, economical, and sustainable technique for the reduction of organic load and nutrients in the systems of organic effluents treatment. This system still presents landscape advantages, with research aimed to use ornamental plants in its construction. Although this technology is already widespread and widely used in the world, the Brazilian researchers began their studies on the subject recently, in the 80's. In this work an experimental system of horizontal subsurface flow wetland, with and without recycle, it was studied using the macrophyte Crinum americanum, fed with synthetic organic effluent for a period of 6 months. The objective of the study was to analyze the efficiency of organic matter, phosphorus, nitrate and turbidity removal, besides the monitoring of the plants development and evaluation of the hydraulic detention time of the effluent. The results showed that the system has potential for nutrient removal, phosphorus removal efficiency averaged 83.01% and nitrate 74.25%. For organic matter, the removal was equal to 47.1%. The values of pH, turbidity and temperature obtained from the treated effluent are in accordance with Conama Resolution no. 357/2005 and 430/2011, respectively. In relation to the hydraulic detention time, the best pollutant removal indicators were reached in 12h. The bulbs developed, according to the measurements made during the 6 months, the macrophytes of the planted system reached stems with an average of 20 cm, however, it was not possible to visualize their flowering period.