Avaliação de risco no reúso de esgotos domésticos utilizados na agricultura

Abstract

Water scarcity is a current problem of global relevance. In the national scenario, this reality reaches high levels of drought in most of the year, especially in the semi-arid region, and it is necessary to search for mitigating alternatives, such as agricultural reuse, a practice commonly used in several countries, and growing in Brazil. However, the country does not have specific legislation that includes qualitative and quantitative recommendations that guide the use of sewage and possible impacts to health and the environment. In this sense, this work carried out a qualitative sensorial diagnosis in the residents of the vicinity of Domestic Sewage Treatment Stations, in order to evaluate the impacts caused by the operation. At the same time, from the guidelines and international legislation dealing with this issue, a bibliographical review was carried out to propose safety limits for agricultural reuse and subsequent definition of qualityindexes (IRA, ITR, RAS), involving the parameters of greater meaning (physical, chemical, biological). In the application of these indices, the municipalities of Caiçara do Rio do Vento, Parelhas, Pedro Velho and Santana do Seridó, located in Rio Grande do Norte, were used as a field of action, due to the existence of reuse activities for human and animal feeding. In the perception carried out in Parelhas and Pedro Velho, the impacts produced by the treatment system, such as the odor and proliferation of mosquitoes -causing economic, social and sanitary problems -contribute to population rejection. Onthe other hand, there was considerable acceptance in the reuse of sewage in agricultural activities. When dealing with the limits and indexes proposed, these are the first step towards a future regulatory incorporation of the activity, having as primary field of application the semiarid, but expandable to the different regions, by the similarity in the conditions, efficiency and operation of the Stations of the country, composed mostly of systems of Stabilization Ponds.