Use of constructed wetlands system (CWS) in the treatment of vinasse and evaluation of their toxicity per histological and molecular analyzes

Abstract

Water is an essential factor for the maintenance of vital functions of living beings. Have been seen an increasing impairment of quality of this resource, due to pollution from many sources and even entire watersheds, either by industrial waste, sewage, or, for substances used in agriculture, such as pesticides, herbicides and fertilizers. The vinasse, a byproduct of ethanol production from sugarcane (Saccharum sp.), is used, mainly in Brazil, as fertilizer. This substance has significant polluting power due to its high concentration of organic matter, which can reach water by percolation and/or leaching. The constructed wetlands systems (CWSs) are highly effective biogeochemical systems to treat wastewater from different sources. The CWSs have natural processes of aquatic macrophytes, which not only directly accumulate pollutants in their tissues, but also act as catalysts for purification reactions that commonly occur in the rhizosphere of plants, which is an alternative treatment for vinasse. Fish are excellent models for experimental studies of aquatic toxicology, because warn of the potential danger of chemicals or the possibility of environmental pollution. Several observed responses in these organisms are excellent biomarkers, for example, histopathology of liver and gill, investigation of the molecular mechanisms that indicate cellular stress. Given the above, this project aims to check the effectiveness of phytoremediation treatment of vinasse from sugar cane through the use of CWS and analyze the toxicity of vinasse treated using ultra morphologic, histological, histochemical analysis and molecular tests in tilapia, using gills and liver of these animals. (AU)