Biological CO₂ fixation with production of microalgae in wastewater – A review

Biological CO₂ fixation and wastewater treatment by using microalgae has recently received growing interest. Microalgae can be cultivated in photobioreactors by utilizing CO₂ from point sources such as power plants, cement manufacturing facilities and waste water from industrial, municipal, dairy facilities. These processes can provide the nutrient sources for sunlight microalgae photosynthesis. Thus, microalgae culture can contribute simultaneously to both CO₂ fixation and wastewater treatment. This article presents a critical review, focusing on various photobioreactors and microalgae species cultures in wastewater that can capture high amounts of CO₂ and provide high quality biofuel. In this respect, a number of relevant topics are discussed in this review: a) current wastewater treatment processes, b) wastewater treatment using microalgae, c) classification of photobioreactors, d) microalgae growth parameters and d) the CO₂ capture mechanism.