TRATAMENTO E UTILIZAÇÃO DE ESGOTOS DOMÉSTICOS NA HORTICULTURA FAMILIAR

Abstract

The population growth and the uncontrolled technological advance, have contributed to the increase of the demand by water resources. Water reuse constitutes any alternative to the supply especially in the semiarid region in the Northeast of Brazil, where the rains are irregularly distributed. Studies show that domestic sewage treated in stabilization ponds, can be applied as an alternative source of water for agriculture, specially, in small agriculture areas. The present research is aimed at treating the residual domestic water, us ing anaerobic systems, followed by polishing ponds, with the objective to produce an effluent with microbiological and parasitological characteristics, that are compatible with the standards recommended by WHO (1989). Also compared was the effect of the fe rtile- irrigation on the productivity of the fertilised treatment (mineral and organic fertilizers). The results show that irrigated lettuce with effluent of the polishing ponds (TDH 16 days) showed a smaller contamination than to the one established by the Resolution 12, of ANVISA. However, the lettuce produced with decanted effluent kept the hygienic quality at non-acceptable levels. The greatest observed productivity, was obtained with irrigated lettuce by decanted effluent, but it must not be used for irrigation, because it shows a high concentration of pathogens. The value of fertilizing of nutrients in the sanitary sewer, in general, it is considered beneficial, because their treated effluents have macro and micronutrients necessary to a good performance of agriculture, besides they can substitute the natural fertility of the soil and/or the fertilizer application, when they are not sufficient to keep the plants nutritional necessities for a long time.