Determination of Microbiological Quality and Chlorophyll Levels Lettuce Grown Hydroponically With Wastewater

The study aimed to determine the microbiological quality for coliform in three lettuce cultivars grown hydroponically with optimized solutions. The study was conducted in a protected environment and driven in a hydroponic system adopting the technique of laminar flow nutrientes-NFT, on the premises of the State University of Paraíba-Campus II in Lagoa Seca, PB having the following coordinates- 7°10′15″S; 35°51′14″W. The experimental design was a randomized block with a split-plot treatment in 7 × 3 factorial, with three replicates whose factors were 7 hydroponic solutions with three lettuce cultivars. The optimized solutions were formulated taking as reference the nutrient solution Furlani. The plot was constituted by nutrient solution (S). S1 = Furlani solution; S2 = domestic wastewater; S3 = optimized domestic wastewater; S4 = well water; S5 = optimized well water; S6 = wastewater from the UASB reactor and S7 = optimized wastewater from the UASB reactor and as for the subplot the three lettuce cultivars (Thais, Vanda and Veronica). In none of the samples of the three lettuce cultivars in the first experiment did the microbiological quality increase at 45°C, by the Most Probable Number (MPN) table, when the tube combination was 0-0-0, that is, without growth in none of the tubes, it is assumed that the MPN is less than 1.8 μg. ll samples were considered acceptable for the microbiological standard of thermotolerant coliforms at 45 °C/g. The leaf chlorophyll content is positively correlated with the N content in the plant.