A Comprehensive Review on Microalgae‐Based Biorefinery as Two‐Way Source of Wastewater Treatment and Bioresource Recovery

Abstract

In the past few years, microalgae have gained huge recognition from the scientific community due to their potential applications in the production of a broad array of bio‐based products varying from biofuels to nanoparticles. Due to their elevated growth rate, high tolerance to various types of abiotic stresses, and complex metabolic capacity, microalgae can be used as promising tools for the attainment of a circular bioeconomy. Moreover, they can simply utilize nutrients from wastewater for biorefinery purposes, resulting in resource recovery coupled with wastewater treatment. However, due to their sub‐optimal yields and high production costs, microalgae‐based bio‐products have not yet been commercialized. This review provides insights into the employment of microalgae as an efficient bioresource for the treatment of wastewater with simultaneous enactment as a biorefinery to produce biofuels, biochar, bioplastic, fertilizers, and other high‐value bioproducts. Furthermore, the application of microalgal nanoparticles in wastewater treatment and prospects for genetic modification of microalgae for enhanced biorefinery capabilities have also been briefly highlighted.

Microalgal Consortia for Waste Treatment and Valuable Bioproducts

“…Meanwhile, numerous studies have reported that high-value-added products, including pigments, nutraceuticals, and lipids, as well as animal feeds and gas biofuels, such as CH 4 and H 2 , could be gained concomitantly with wastewater treatment by microalgal consortia processes depending on the type of wastewater treated and the culture conditions (Figure 2) [56,[89][90][91][92]. Additionally, the concept of an algal bio-refinery with wastewater treatment allows for the increased utilization of microalgal biomass when applied to biofuel production as well as allowing for long-term economic viability and the reduction in residuary wastes associated with wastewater treatment [93]. During microalgal-bacterial consortia wastewater treatment processes, it was observed that bacteria release EPS that mediate their aggregation with various microalgae [1,22,94].…”

Gold Nanoparticles Bioproduced in Cyanobacteria in the Initial Phase Opened an Avenue for the Discovery of Corresponding Cerium Nanoparticles

“…The key advantage of biogenic NPs is their small size, which allows them to better reach the application site and act in a more targeted manner, reducing unwanted side effects. This eco-friendly biosynthesis offers significant opportunities for innovative applications in food processing, preservation, packaging [ 14 ], resource recovery [ 15 ], and wastewater treatment [ 16 ]. This is due to their remarkable properties at the nanoscale, including small particle size, large surface-to-volume ratio, and adjustable morphological properties [ 17 ].…”