The rapid population increase and subsequently the increase of anthropogenic activities have a growing impact on the environment. More than fifty thousand chemicals are regularly introduced into the environment affecting also the aquatic system, especially the groundwater system, which represents the world’s larger freshwater reservoir. It is highly important to find an efficient biotechnological solution for wastewater treatment and the microalgae-bacteria granular system offers a better alternative solution.
The population and economic growth have generated a significant new number of pollutant compounds which have to be degraded before reaching the environment. The wastewater treatment plants (WWTPs) have been the last barrier between the domestic and/or industrial wastewaters and the environment. At present, the conventional WWTPs have very high operational costs, most of them linked to the aeration process (60-65% from total energy costs related to wastewater treatment).