Microalgae Harvesting: A Review

Abstract

Microalgae are photosynthetic autotrophic microscopic organisms growing in a range of aquatic and terrestrial habitats. They produce a huge complex of compounds in their surroundings which are of important use to humans. Their commercial use lies in human nutrition, animal and aquatic feed, in cosmetics products, natural pigments, pharmaceutical industry, bio-fertilizer for extracting high-value molecules, stable isotope biochemicals, and for the synthesis of antimicrobial, antiviral, antibacterial and anticancer drugs. Therefore, it is necessary to develop a simple, effective and economically advantageous method for harvesting the algal products. Magnetic separation is a simple separation process. Different synthesis methods have been used by researchers to obtain magnetic particles of varying size and shapes according to the algae to be studied. Chemical co-precipitation method has been the most commonly used method, which helps in synthesizing magnetic particles of the micro to nano range. Naked, coated and surface modified are the general types of magnetic particles used for algal harvesting with its own advantages and disadvantages.

The potential use of natural coagulants for microalgae harvesting: a review

“…Harvesting can be done through different means (physical, chemical, or biological) (Milledge & Heaven 2013;Difusa et al 2015), and the method used should ensure that both biomass and wastewater are gathered for future use. 'Centrifugation, filtration, flotation, bio-flocculation, electrocoagulation, flocculation, and sedimentation' are the most often utilized procedures (Christenson & Sims 2011;Kucmanová & Gerulová 2019;Lam et al 2019). The selected method should aim for low prices, low energy requirements, simple processes, and broad application to a wide range of species (Mata et al 2010).…”

Evaluation of Pb, Mg, Al, Zn, and Cu as Electrode Materials in the Electrocoagulation of Microalgae

“…Furthermore, the unicellular nature of microalgae has piqued scientists' interest in doing additional research on microalgae biomass production as it implies ease to culture and minimal upkeep. Even though the culturing of microalgae requires minimal supervision [4], the process of harvesting microalgae has proven to be complicated [5]. This is mainly due to the microscopic size of microalgae cells (5-10 µm for Chlorella vulgaris) and the fact that they possess a negative surface charge, resulting in high colloidal steadiness in suspensions [6].…”