Biorremediación de nitratos y amoníaco de las aguas del río San Pedro mediante el uso de un consorcio microalgal a escala de laboratorio

Abstract

The objective of this research was to evaluate the bioremediation capacity at laboratory scale of nitrates and ammonia in the waters of the San Pedro river, by means of a microalgal consortium that was isolated from the river water samples, which is composed of Chlorella sp and Diatomeas sp. native to the river, as well as microbiological tests in which total coliforms were identified. A completely randomized experimental design was applied, which consisted of a control (river water) and 4 treatments, with three replicates each; T1: 920 mL river water + 80 mL of microalgal consortium + photoperiod, T2: 920 mL synthetic water + 80 mL microalgal consortium + photoperiod, T3: 920 mL river water +80 mL microalgal consortium + darkness and T4: 920 mL synthetic water + 80 mL microalgal consortium + darkness, with physical conditions of: pH a range between 6. 5 to 7.5, temperature 15 ºC to 28 ºC, constant aeration and photoperiod of 2000 lux. The evaluation time of the treatments was 4 weeks; the cell count was performed twice a week, for the nitrate analysis it was performed every week and for the ammonia analysis it was performed in the second and fourth week. The results at the end of the investigation were: the consortium culture reached a cell density of 9.26x104 cells/mL, the best treatment for nitrate removal was T1, which reached a removal percentage of 97.59 % and the best treatment for ammonia was T3 with values of 0.53 mg/L initially and ending with 0.55 mg/L. Through this research, it has been demonstrated that the microalgae Chlorella sp has a great capacity to absorb and eliminate pollutants present in wastewater