Wastewater treatment by microalgae.

The growth of the world's population expands the demand for fresh water, food, energy and technology, which on their turn lead to increasing amount of wastewater, produced both by domestic and industrial sources. These different wastewaters contain a huge variety of organic and inorganic compounds, which can cause tremendous environmental problems if released untreated. Traditional treatment systems are usually expensive and energy demanding and often still not capable of facing all challenges presented by the produced wastewaters. Microalgae are promising candidates for wastewater reclamation as they are capable to reduce the amount nitrogen and phosphate as well as other harmful compounds like heavy metals or pharmaceuticals. Compared to the traditional systems, photosynthetic microalgae require less energy input, since they use sunlight as their energy source, and at the same time they lower the carbon footprint of the overall reclamation process. This mini-review focuses on recent advances in wastewater reclamation using microalgae. The most common microalgal strains used for this purpose are described as well as the challenges of using wastewater from different origin and the impact of climate, especially Nordic climate. Besides, the need is addressed to develop technical solutions for bioreactors used in microalgae-based wastewater treatment. This article is protected by copyright. All rights reserved.