Removal of nitrogen and phosphorus by microbial stimulation in a mesocosm of eutrophicated water

With the accelerated industrialization and expanding urbanization of today, healthy water resources are becoming increasingly important. However, changes in environmental conditions and diverse anthropogenic activities lead to water contamination, which is a global concern. The use of water reservoirs to sustain domestic, agricultural, and industrial activities alters the water cycle, while non-treated effluents and the lack of hydric intake into reservoirs increase the concentration of macronutrients in these systems, such as nitrogen (N), phosphorus (P), carbon (C), calcium (Ca), and sulfates, thereby raising the probability of eutrophication problems. This leads to the rapid multiplication of plankton, resulting in the variation in dissolved oxygen (DO), the deterioration of water quality, and the death of organisms inhabiting these waters, further affecting the utility value of their resources. In this study, the removal of N and P was evaluated in a sample of eutrophicated water from a dam through the bio-stimulation of the native population in a mesocosm with controlled aeration for 25 days, achieving removals of 99 and 95% of the total N and P, respectively. These results highlight the importance of stimulating native microorganisms by increasing the OD, to improve biological treatments for nutrient removal; additionally, the importance of using systems that simulate the environmental conditions of water bodies to study their biotreatability is shown.