Evaluation of nutrients removal (NO₃-N, NH₃-N and PO₄-P) with Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and a consortium of these microorganisms in the treatment of wastewater effluents

In this research removal of NH₃-N, NO₃-N and PO₄-P nutrients from municipal wastewater was studied, using Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and an artificial consortium of them. The objective is to analyze the performance of these microorganisms and their consortium, which has not been previously studied for nutrient removal in municipal wastewater. A model wastewater was prepared simulating the physicochemical characteristics found at the wastewater plant in Chapala, Mexico. Experiments were carried out without adding an external carbon source. Results indicate that nutrient removal with Chlorella vulgaris was the most efficient with a removal of 24.03% of NO₃-N, 80.62% of NH₃-N and 4.30% of PO₄-P. With Bacillus cereus the results were 8.40% of NO₃-N, 28.80% of NH₃-N and 3.80% of PO₄-P. The removals with Pseudomonas putida were 2.50% of NO₃-N, 41.80 of NH₃-N and 4.30% of PO₄-P. The consortium of Chlorella vulgaris–Bacillus cereus–Pseudomonas putida removed 29.40% of NO₃-N, 4.2% of NH₃-N and 8.4% of PO₄-P. The highest biomass production was with Bacillus cereus (450 mg/l) followed by Pseudomonas putida (444 mg/l), the consortium (205 mg/l) and Chlorella vulgaris (88.9 mg/l). This study highlights the utility of these microorganisms for nutrient removal in wastewater treatments.