Bacterial-algal coupling system for high strength mariculture wastewater treatment: Effect of temperature on nutrient recovery and microalgae cultivation

In the present study, bacterial-algal coupling system, an integration process of acidogenic fermentation and microalgae cultivation was used for high strength mariculture wastewater (HSMW) treatment, resource recovery and low-cost biomass production. The effect of temperature on Chlorella vulgaris (C. vulgaris) cultivation was investigated with culture medium of acidogenic liquid. The results showed that acidogenic liquid could be used as culture medium for C. vulgaris and higher biomass was obtained compared to control. The acidogenic liquid obtained at initial pH of 8 was the most suitable culture medium for C. vulgaris growth due to befitting C/N and considerable volatile fatty acids. Moreover, the optimum temperature for C. vulgaris cultivation was 25 degrees C and the removal efficiency of chemical oxygen demand (COD) and NH4+-N from acidogenic liquid could reach 94.4% and 68.8%, respectively. The outcome could create an innovative value chain with environmental sustainability and economic feasibility in aquaculture industry.

Automated summary

The study demonstrated that using acidogenic liquid as a culture medium for Chlorella vulgaris cultivation resulted in higher biomass, with the most suitable culture medium being acidogenic liquid with an initial pH of 8. The optimal temperature for Chlorella vulgaris cultivation was found to be 25 degrees Celsius, with removal efficiencies of 94.4% for chemical oxygen demand (COD) and 68.8% for NH4+-N from the acidogenic liquid. This outcome could lead to an innovative value chain in the aquaculture industry with environmental sustainability and economic feasibility.