Preliminary study of production of biomass of Chlorella vulgaris utilizing recycled nutrients in sediments from Catfish ponds

Abstract

Feasibility of growing Chlorella vulgaris on recycled nutrients in sediments from Catfish ponds was evaluated, where a sediment filtrate-based organic media was prepared in single and double strength (100% and 50%) and tested against a conventional synthetic media (F/2) for algae culture. Findings from the study showed that sediment filtrate media (SFM) was not only able to support the growth of Chlorella vulgaris, but also yielded a significant quantity of biomass. Results for biomass density estimation showed that there was a correlation between nutrient concentration and biomass concentration because more algae concentration was recorded in the highest media concentration (100%) than the lower concentration (50%). This trend was observed for all treatments. Similarly, findings from the study also revealed that the 6^th day of culture was the optimum culture period for harvesting because the highest biomass density was obtained within this period for all mediums. Furthermore, biomass yields and productivities of Chlorella vulgaris showed varied productivities and yields for both SFM and F/2 mediums. For the 3rd day, the highest productivity was obtained in f/2 medium with a productivity of 0.44g/L/day (44.3%). Similarly, in the 6th day, the highest biomass productivity was recorded in F/2 medium with a productivity of 0.17 g/L/day (17%). Even though the synthetic medium (F/2) outperformed SFM, results from the biomass productivities are promising if the growth conditions are optimized. The outcome of this study can serve as a baseline for developing technologies that will encourage the utilization and management of sediments from catfish ponds in the Kainji Lake Basin.