Recent trends in microalgal harvesting: an overview

In this modern era due to multidimensional problems associated with petrochemical fuels, the scientific community is showing a burgeoning interest in microalgae due to their potential applications which are indispensable for economic amelioration. Microalgae are a fundamental source of oils and various other biomolecules that can be used in the production of biofuels and various other value-added bioproducts. However, implication of microalgae-based biofuels is not economically viable due to various factors. One of these prime reasons is the cost associated with its harvesting. This review focuses on various harvesting techniques applied to microalgae in the last 2/3 decades, presenting the main benefits and drawbacks of each method to allow the selection of appropriate method(s) for economically harvesting microalgal biomass. According to this review, use of any single technique is not viable for harvesting microalgal biomass. However, keeping in view the morphological characteristics of the microalgae, growth density, utility purpose of the harvested biomass, harvesting scale and physico-chemical characteristics of the production medium, these techniques should be applied in suitable combinations to obtain fruitful results.