Wastewater chlorination for reuse, an alternative for small communities

Abstract

Reuse of wastewater is a practice that has been employed all over the world, mainly in agriculture, where the main aim is to reduce the demand for water and provide nutrients. However, these waters for reuse often have excessive amounts of pathogenic microorganisms, requiring a specific disinfection step even after being subjected to a purification process. Thus, this research aimed to evaluate the potential use of calcium hypochlorite and sodium hypochlorite as disinfectant agents for the sanitary effluent of the treatment system based on constructed wetlands for later reuse. Disinfection tests were carried out in batch, using three dosages of hypochlorite (5, 10 and 15 mg.L -1 ) and different contact. In all disinfection tests, inactivation of indicator microorganisms (total coliforms and E. coli) was considered effective for the two disinfectant agents adopted, satisfying the criteria for reuse according to the World Health Organization (WHO). There was no formation of trihalomethanes after disinfection tests.