Tecnologia de tratamento de água e resíduos

Abstract

Managing water resources is a great challenge on economic developing and public health. Due to the continuous growth of concern on behalf of this resources, promoting development of technologies capable of reaching the balance between demand and offer of water is important. Therefore, domestic sewage becomes a product, and it’s possible to generate quality water to satisfy activities that need most in quantitative terms, through an efficient treatment. Among the treatment procedures of water, a technology widely known that allows the improvement of effluent quality is slow filtration and can be used with other technologies to achieve more efficiency, as an example, nonwoven material. Consequently, this research has the objective to compare the behave of different kinds of filtration media on slow filtration, and evaluate system’s capacity to treat domestic sewage, pretreated with an activated sludge system, aiming the production of urban reuse water of class II. In this regard, four slow filters were built, they differ the filtration media. The materials used were sand (FLA), synthetic nonwoven material (FNT 1), needled nonwoven material of 20 cm (FNT 2) and needled nonwoven material of 30 cm (FNT 3). To evaluate system’s efficiency, it was observed the physical, chemical and microbiological parameters of the activated sludge system (used as affluent of the filters) and effluents produced by slow filters. As result, the average efficiencies obtained were 80%, 50%, 44% and 38% on removing turbidity, DQO, SST and SSV, respectively, for the FLA. FNT 1 had average efficiency of 32% and 27% on removing turbidity and DQO. FNT 2 had average efficiencies of 83%, 46%, 48% and 49% on removing turbidity, DQO, SST and SSV, respectively. Finally, FNT 3 had average efficiencies of 74%, 43%, 41% and 43% on removing turbidity, DQO, SST and SSV, respectively. In the background, for ammonia parameter it was verified low removal post filters, and for phosphorus there were not differences between affluent and effluent. There were not helminth eggs on the effluent of the filters, the concentrations of Total Coliforms -1 and E. Coli obtained were about 10³ NPM.100 mL order. Concluding that slow filter with needled nonwoven material as a filter media presents equivalency with sand slow filter that is a known system. However, FNT has operation and cleaning facilitations, besides a shorter maturing time comparing to FLA.