Desempenho de gotejadores operando com percolado de aterro sanitário diluído sob pressões de serviço

Abstract

The population growth and intense urbanization process, coupled with the excessive consumption of natural resources, are responsible for the exponential increase in the quantities of solid urban waste generated. The arrangement of these in landfills is a common practice; however, this provision requires environmental protection measures, including the treatment of leachate liquid. Due to the scarcity of water in semiarid of northeast, the use of this percolate in agriculture through drip irrigation systems becomes an effective strategy for this region. Considering that, the work aimed to analyze the effect of different service pressures in the performance of drip irrigation systems operating with landfill leachate diluted in water supply. To conduct the tests, it was mounted an experimental bench in the Experimental Unit of Water Reuse (EUWR), which has a total area of 793.13 m2, installed on the Zoo and Botanical Park located at the Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró Campus. The hydraulic performance and the levels of obstruction of the units irrigation applying landfill leachate diluted in water supply were evaluated for 160 h; for that, was mounted an experimental with two factors, the first factor being the three types of emitters (G1, G2 and G3) and the second factor the four operating pressures (P1 - 70 kPa, 140 kPa -P2, P3 - 210 kPa and 280 kPa - P4) in three replicates (three lateral lines by dripper type in each irrigation unit). In every 20 hours of the system s operation it was evaluated the CUC, CUD, CVQ, Us, Q, QR, RQR, APQ and RPQ. The data were submitted to analysis of simple and multiple regression and parametric test of Pearson correlations. The results evidenced that the formation of biofouling resulting from the interaction between the physical, chemical and biological agents occasioned to partial and total clogging of the drippers and consequently reducing in the hydraulic performance of irrigation units which operate with landfill leachate diluted in water supply. The greater susceptibility to clogging was observed for the dripper G2, operating at service pressure P1 (70 kPa). The dripper G3 operating at pressures of service P1 (70 kPa) and P2 (140 kPa) were the combinations that best attenuated clogging. The empirical models null, linear and square root were the best fit to the relation between the variables of hydraulic performance and operation time of units irrigation, for the combinations between types of drippers and service pressures of units irrigation