Qualidade sanitária e ambiental do gergelim irrigado com água residuária tratada.

Abstract

The purpose of this experimental research was to investigate health, environmental and production of sesame (Sesamum indicum L.) cv aspects. BRS - G4, irrigated with treated wastewater, observing microbiological concentration of seeds in comparison with the standard Coliforms at 45 ° C, without causing harm to human and animal health. The experiment was conducted in a greenhouse located at the Center for Technology and Natural Resources, the Federal University of Campina Grande - UFCG, Campus de Campina Grande - PB. The experimental design was randomized blocks of type, in a 3x3 factorial design with four replications, totaling 36 experimental plots of factorial design with two factors: two wastewater treated by UASB Wetland and post-treated with wetland systems, and water supply as witness. The other factor, were three types of localized irrigation, surface drip, subsurface drip and spray. In the second soil analysis performed immediately after harvesting of sesame, after five months of use of irrigation with treated wastewater, showed changes in their physicochemical properties, evolving into a saline soil, C3 medium salinity, with the same RAS 4.23 and the percent saturation of 27%. The pH of from 6.6 to 6.8. Microbiological analysis of soil, soil samples collected after harvest of sesame was detected concentration (6.6 x 105UFC / 100mL Coliforms at 45 ° C), while in the native soil, the concentration was (0,405x103UFC / 100 mL coliforms at 45 ° C), assigning these relative levels of CFU / 100mL in the soil, with the use of wastewater, which showed concentrations (≤ 1 069 MPN / 100 ml coliforms at 45.) and a removal rate of 58 bacteria 31%. However, in comparison with that soil water treated by the UASB post-treated wetland system, it was found that the bacteria removal rate was 54.00% and showed an average concentrations (≤ 989 MPN / ml Coliforms at 100 45 ° C) for water samples analyzed at 90 DAP, thus confirming, in accordance with the standards recommended by the current legislation, the concentration (≤ 1000NMP / 100 ml Coliforms at 45 ° C). The microbiological results of the grains of sesame, the analysis in the laboratory, for plots that received water from the wetland system, revealed a concentration (> 102NMP / g Coliforms a45ºC) above the adopted standard. Although the microbiological analysis, confirm the presence of Coliforms at 45 ° C and E. coli, for the treatments (T1, T4, T7), with the lower recommended standard for plant foods, (≤100NMP / g) values, measured by safety, it is considered Coliform bacteria. And the microbiological results of grain sesame, produced with the water supply, the laboratory analysis showed similar results to the results of UASB. The treatments (T3 = 1,4nmp / g T6 = 1,1nmp / T9 = 0,36nmp g / g) for the samples, are in accordance with standard and are suitable, it should be recommended for use in food and of warm-blooded animals. The efficiency of the irrigation system, shows a degree of acceptability for regular drip irrigation systems, where each system individually analyzed for subsurface drip, surface drip and micro sprinkler with uniformity coefficient distribution (cud) of 80%, 77% and 73% respectively, compared to flow transmitters; however, showed a high degree of acceptability bad when the three systems were combined to give a percentage of 67% (cud). The flow rate of the emitters used in the experiment was not affected by the type of water used.