The effect of Pseudomonas putida on the variation of biochemical oxygen demand in the effluents of the domestic WWTPCollique, Lima

Abstract

In Peru, many effluents from domestic wastewater treatment plants often contain high concentrations of biological, physical or chemical contaminants; constituting low quality effluents. In this context, the aim of this research was to evaluate the effect produced by the bacterial strain Pseudomonas putida ATCC 49128 on the variation of biochemical oxygen demand (BOD₅) of effluents extracted from the domestic wastewater treatment plant (WWTP) located in the town of Collique, in the district of Comas, in the province of Lima, Peru. We conducted our experimental research for a period of 120 hours, establishing three treatments and a control, with three repetitions each. The known sources of variation were the different concentrations of P. putida ATCC 49128, in a ratio of 1x10⁸, 1.5x10⁸ and 2x10⁸ CFU/ml. The results demonstrated maximum reductions in BOD₅ and COD of 54.79% and 51.62%, respectively. Furthermore, variations in the pH were evident, with fluctuations between 6.60 and 8.23, which is considered optimal for the purification process of the strain. In the experimental medium, the temperature varied very little, between 25.36°C and 27.47°C, making it statistically constant (p = 0.149 > α = 0.05). Through our research, we were able to conclude that the bacterial strain Pseudomonas putida ATCC 49128 produced a significant effect in the reduction of BOD₅ in the WWTP effluent wastewater.