Magyar, TamásSpahiu, Rozafa2024-05-232024-05-232024-04-25https://hdl.handle.net/2437/370183Microalgae, e.g. Chlorella vulgaris cultivation could contribute to achieve several sustainable development goals (SGDs), such as zero hunger, clean water, and sanitation as well as affordable and clean energy. Moreover, microalgae are known as the most efficient biological sequesters, since the photosynthetic process results in the conversion to carbohydrates and oxygen from the captured CO2, meanwhile a large amount of biomass is generated that can be used as animal feed, substrate for biofuel production and a protein supplement. The objective of the research was to investigate the biomass productivity of Chlorella vulgaris microalgae in a self-developed, optimized N:P ratio nutrient solution (T3) with variable CO2 injection (0 mL·min-1 (reference), 2 mL·min-1, 3.5 mL·min-1 and 5 mL·min-1). To characterize the biomass growth as well as the nutrient consumption over the 6-week-long experiment, several biological (chlorophyll concentration and microalgae activity rate) and physico-chemical (NH4+, NO3-, K+, PO43-, COD, pH, EC, and temperature) parameters were monitored weekly. These parameters across altered CO2 injection rates have shown distinct patterns of fitting. Notably, the type of fitting for these parameters varied depending on the CO2 injection rate, with logarithmic and linear trends observed. The decrease in these parameters suggests that the microalgae are effectively utilizing nutrients for growth, emphasizing the potential of optimized N:P ratio nutrient solutions coupled with variable CO2 injection to enhance microalgae biomass productivity. During the cultivation process, a pH drop was observed in all samples due to the CO2 injection, therefore a 0.1 mol dm-3 NaOH solution was used for the pH stabilization. Overall, it was found that 2 mL·min-1 of CO2 injection could significantly enhance the photosynthetic activity resulting in higher chlorophyll concentration with 60.65% compared to the control, while 5 ml·min-1 inhibited the microalgae cultivation.64enMicroalgae; biomass productivity; sustainability; nutrient solution; carbon- dioxide sequestrationKörnyezettudományokMűszaki tudományokHozzáférhető a 2022 decemberi felsőoktatási törvénymódosítás értelmében.