A major consumer of available water on the planet is agriculture, it is estimated that 70% of water global use is devoted to this activity. Thus, the reuse of sanitary effluents appears as a viable alternative to supply the demand of the agricultural sector, however one of the difficulties found to make safe reuse feasible is to determine an efficient disinfection system in the Giardia cysts inactivation. This pathogen is the most found in fecal exams around the world. Thus, the present work aims to evaluate the use of different disinfectants (calcium hypochlorite, peracetic acid, hydrogen peroxide, UV-LED radiation and the advanced H2O2 / UV-LED oxidative process) in the Giardia cysts inactivation. In addition, the research will seek to determine the impacts caused to the soil microbiota by the application of treated and disinfected effluent. For the first stage of analysis, a solution of ultrapure water, supplemented with nutrients and artificially inoculated with a known number of cysts will be used. The disinfectants will be tested at different concentrations and contact times in order to determine the ideal condition of each of them. Following the work, these ideal conditions will be tested in effluents from two treatment systems that use real sewage: a bench scale, anaerobic filter + sand filter, and another from a treatment plant in the city of Campinas-SP (UASB + Biological filter percolator). The disinfected effluents will also be evaluated with the use of toxicity tests with test organisms, and will be arranged in the soil to monitor the possible effects caused to the physical-chemical properties and the microbial community of the soil. In addition, the dry matter yield and the nutritional status of the plants that receive the disinfected effluent application will be evaluated through greenhouse experiments using sunflower, castor bean and soybean.
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