Simultaneous CO۲ Bio-fixation and Tuna Processing Factory Wastewater Treatment via Microalgae

Photosynthetic microorganisms such as Chlorella vulgaris can be used for carbon dioxide (CO۲) biofixation to reduce greenhouse gas emissions and combat global warming. In this study, the potential of using wastewater from a tuna processing factory as a cultivation medium for C. vulgaris was investigated with the aim of reducing cultivation costs and water consumption while treating the wastewater. Different CO۲ concentrations (۵%, ۱۰% and ۱۵% in N۲) and wastewater dilutions (۱:۴, ۲:۴, ۳:۴ and ۴:۴) were tested at ambient temperature, controlled pH and cyclic illumination (۱۲h light-۱۲h dark) at ۶۰۰۰ lux, using both batch and semi-continuous cultures. In the batch system, ۱۰۰% CO۲ biofixation was achieved at an effluent dilution of ۱:۴ and ۵% CO۲, with biomass concentration doubling after one week. High removal rates of COD (۹۴%), total phosphorus (۹۹%), nitrate (۹۸%) and ammonium (۹۹%) were observed. The semi-continuous photobioreactor showed a CO۲ stabilization of more than ۵۰% (at ۵% CO۲) and a ۴۰% biomass increase, with over ۵۰% nitrate removal in a ۱:۴ dilution effluent. These promising results demonstrate the potential of the system for simultaneous CO۲ biofixation and wastewater treatment and underline the effectiveness of this circular economy approach to reduce greenhouse gas emissions and treat industrial wastewater.

کلیدواژه ها:

Chlorella vulgaris ، CO۲ Bio-Fixation ، Tuna Processing Factory Wastewater ، photobioreactor