Optimization of Chlorella pyrenoidosa Y3 biomass production in poultry waste anaerobic-digested effluents using a response surface methodology.

Coupling microalgae cultivation with wastewater treatment may provide an economically and environmental friendly way for the production of algae-based biofuel or other value-added products. The nutrient supplement to poultry waste anaerobic-digested effluent (PWADE) as the substrates forChlorella pyrenoidosaY3 (isolated from Tai Lake) cultivation was investigated and optimized using a response surface methodology (RSM). Based on the Plackett–Burman design, NaHCO3and MgSO4·7H2O were selected as the most crucial supplemental nutrients for enhancing the biomass yield and chlorophyll-a content ofC. pyrenoidosaY3. A central composite design was employed to determine the optimal concentration of the two selected supplemental nutrients. With the canonical and ridge max analysis method, the maximum biomass yield of 0.819 g/L was obtained from algae cultivated in the 2% (v/v) PWADE substrate with addition of 4.81 g/L NaHCO3and 92.9 mg/L MgSO4·7H2O after 20 d of the cultivation, which was 1.5 times higher than that of algae cultured in the non-optimized PWADE medium (0.559 g/L). The chlorophyll-a content of algae reached to 27.51 mg/L, and about 100.0% NH4-N and 59.5% total phosphorus were removed from the PWADE with the optimized medium condition. Results indicate that RSM is a reliable method in proposing models for optimizing the algae growth in PWADE. [ABSTRACT FROM PUBLISHER]