This laboratory study cultivated Chlorella vulgaris in sterilized and settled grease-trap wastewater. A medium containing 1 g/L calcium hydroxide and an initial density of 5×10^6 cells/mL supported the greatest growth, while COD, nitrate, and phosphate declined over seven days.
Key findings
- The 1 g/L calcium-hydroxide medium produced the highest specific growth rate, 0.318 day−1, and 5×10^6 cells/mL gave the greatest growth. COD fell from an initial 228.00–276.80 to 66.67–212.80 mg/L, while maximum nitrate and phosphate removal reached 91.03% and 75.36%, respectively.
Why this matters globally
Using microalgae to recover nutrients from wastewater supports circular-economy goals by potentially reducing pollution while producing biomass for aquaculture or energy. The study offers starting conditions for a difficult, fat-rich wastewater stream.
Thai researcher contribution
Researchers at Bansomdejchaopraya Rajabhat University developed and tested a process relevant to restaurant and urban-building grease-trap wastewater, a common environmental-management challenge in Thailand.
Limitations to consider
Sterilization and settling make the wastewater less representative of variable real systems containing microbes, fats, and contaminants. The seven-day experiment did not assess biomass quality, pathogens, metals, cost, harvesting, or discharge compliance, so commercial readiness is unproven.