Increasing feasibility of microlagal-based wastewater treatment using different light spectra during cultivation

Wastewater treatment (WWT) has received increasing attention due to rapid industrialization and urbanization. Microalgae-based WWT is a promising approach that can also provide co-benefits such as CO₂ bio-fixation and the production of high-value bioproducts. However, large-scale implementation remains limited because of long processing times and high operating costs. In this study, we investigated, for the first time, the effects of different light spectra (white, green, blue, and red) on the bioremediation performance of microalgae. Blue light at an intensity of ۱۰۰ μmol ms produced the highest biomass concentration (۱.۳۰ g/L) and productivity (۰.۳۰ g/L/d), whereas green light negatively affected microalgal growth. Compared with white light, using blue LEDs increased COD, total nitrogen (TN), and total phosphorus (TP) removal by ۸۸.۵%, ۹۱.۵%, and ۹۳.۸%, respectively. Nutrient uptake mass-balance analysis showed that red LEDs achieved the highest uptake per unit biomass, with COD, TN, and TP values of ۱۷۲.۳, ۱۹.۹, and ۳.۴۷ mg, respectively, per ۱ g of C. sorokiniana. Overall, these findings highlight the advantages of blue light for maximizing microalgal growth and red light for enhancing nutrient uptake under appropriate light intensity, offering a practical pathway to optimize microalgae-based WWT for sustainable, large-scale applications.

کلیدواژه ها:

Waste water treatment ، Light spectra ، Microalgal-based treatment ، Sorokiniana