TRATAMENTO DE ÁGUA RESIDUÁRIA DOMÉSTICA E SUA UTILIZAÇÃO NA AGRICULTURA

Abstract

The treated domestic sewer when available for the agricultural activities provides economy of water of good quality and chemical fertilizers and it motivates to the agricultural activities. In the semi-arid area of Brazil the reuse of water can be an alternative for the coexistence with the shortage of the hydric resources. In this context, the rural workers of the Municipal district of Lagoa Seca, PB, that produce vegetables during all year as source of revenue happening of the family agriculture. Several researches were already accomplished with the purpose of developing technologies of treatment of sewers that produces effluents with smaller risks of transmission of diseases, but guaranteeing appropriate concentrations of nutrients to the irrigated cultures. The present study had as objective to evaluate the sanitary aspects and nutricionais of the effluents of treated sewers in a system formed by a reactor UASB followed by polishing pond. The use of those effluents was also verified in the fertigation of bell pepper (Capsicum annuum L.). Compared with treatments of the soil using mineral and organic manuring, the planting of the bell pepper obeyed the statistical planning of blocks random, with 5 treatments and 4 repetitions. During the experimental period weekly analyses of the effluents were accomplished and of the culture of bell pepper. The pos-treatment of the sewer in the polishing pond produced effluent with sanitary quality inside of the values recommended by the World Organization of Health (OMS, 1989) for irrigation of vegetables consumed raw. The bell pepper irrigated with effluent of the reactor UASB didn't present significant difference of productivity (at the level of 5% of probability for the test Tukey), when compared to the application of mineral and organic manuring.