Response of treated domestic effluent irrigation on microbiological characteristics of bean grown in protected environment

The use of domestic wastewater treated for irrigation may become a viable alternative for regions facing water scarcity. The objective of the present work was to evaluate the microbiological quality of bean (Phaseolus vulgaris L.) BRS-Pontalcultivar submitted to different irrigation depths with treated domestic effluent. The irrigation depths were obtained according to 50, 75, 100 and 125% of the crop evapotranspiration and the concentrations corresponded to 0, 50 and 100% of treated domestic effluent. The experimental design was randomized blocks, in a 3 x 4 factorial scheme with four replications, in a protected environment. The effluent was collected at the Sewage Treatment Station (STS) belonging to the Federal University of Sergipe, SE, Brazil, were the experiment was conducted. The presence of Thermotolerant coliforms (NMP g-1), mesophiles (CFU g-1), molds and yeasts (CFU g-1), and Salmonella were evaluated. The results of the bean grain samples were submitted to analysis according to the parameters recommended by Resolution 12 of the National Agency of Sanitary Surveillance - ANVISA.All the treatments used presented to be within the microbiological standards recommended by ANVISA for human consumption of bean, so it is recommended bean irrigation with 100% of treated domestic effluents concentration or 50% water supply plus 50% treated effluent, thus targeting treated water for other purposes, since there are no thermotolerant coliforms or Salmonella sp.