Electrocoagulation–flotation (ECF) for microalgae harvesting – A review

Harvesting has been recognized as a major bottleneck in any microalgae-based technology, making it a relevant research topic in the field. Among applicable technologies, electrocoagulation-flotation (ECF) has been devoted a lot of attention as an effective alternative to conventional metal salts addition. This paper reports and comments the relevant available literature on ECF, aiming at retrieving and assessing the main parameters affecting process performance by identifying their optimal ranges. After introducing the basic principle of ECF, the paper presents a qualitative analysis of the main factors (electrochemical parameters, microalgae and broth characteristics) and the way they affect the process performance. Then, a quantitative assessment has been performed based on the analysis of a dataset of 190 records from 29 research papers. Metal toxicity and process costs are addressed. Finally, guidelines for future experimentations are discussed in order to support and facilitate the further development of the ECF technology.