Effect of leachate on the growth of marine and freshwater microalgae consortia

Objective. This study evaluated the growth kinetics of marine and freshwater microalgae consortia in different concentrations of leachate extracted from a landfill. Materials and methods. An experimental design was carried out for each consortium (marine Chlorella marina and Nannochloropsis oculata and freshwater Chlorella vulgaris and Ankistrodesmus falcatus) in leachate concentrations of 5, 10, 15% and a control (0%), with one main experiment and three replicates for each concentration (K=4), in batch culture. Results. Significant differences were found in the microalgal growth at different concentrations of leachate for both consortia (H=12.9768; p<0.05 for marine microalgae and H=20.0097; p<0.05 for freshwater microalgae), attributed to a higher growth in the control sample. A significant negative correlation (p<0.01) was also found between leachate concentration and both growth rate and cell division. A lower growth was observed at concentrations above 5% in both consortia. Conclusions. The marine consortium was able to generate a higher cell density, which may increase the effectiveness of the pollutant bioremediation process, despite the negative effect observed at higher amounts of the compound.