Microalgae-Based Wastewater Treatment and Recovery with Biomass and Value-Added Products: a Brief Review

With economic development and population increase, environmental pollution and water shortages have become inevitable global problems. Microalgae-based wastewater treatment technology can not only purify wastewater and solve environmental pollution problems but also use the nutrient elements in wastewater to produce algal biomass, which has attracted more and more attention. This work reviews the current status of microalgae bioremediation of wastewater, aiming to provide a reference for further research in this field.

Microalgae have been proven to be used to treat municipal wastewater, agricultural wastewater, and industrial wastewater and can convert nutrients into biomass. In order to further improve the wastewater treatment efficacy and algal biomass productivity, it is necessary to understand the mechanism of microalgae to remove nutrients and pollutants from wastewater. Currently, open ponds and enclosed photobioreactors are used for large-scale cultivation of microalgae, and various harvesting technologies are developed to achieve low-cost capture of microalgae as much as possible. Microalgae are rich in pigments, proteins, lipids, carbohydrates, vitamins, and antioxidants and can produce a variety of value-added products, making this biotechnology more cost-effective.

This review discusses the purification efficiencies of microalgae on wastewater from different sources and introduces the mechanism and influencing factors by which microalgae remove carbon, nitrogen, phosphorus, heavy metals, and antibiotics in details. Moreover, the advantages and disadvantages of different microalgae cultivation systems are analyzed. Finally, the different harvesting methods and the current application of microalgae biomass in various fields are summarized.