Green technology for bioremediation of the eutrophication phenomenon in aquatic ecosystems: a review

Eutrophication is a serious phenomenon that leads to vigorous algal blooms that alters the structure of ecosystems. It is caused by non-point sources of nutrients; as nitrogen and phosphorus, and point sources as wastewater effluent. Distinctive algae groups are responsible for this phenomenon, such as diatoms, blue-green algae, green algae, and dinoflagellates. Numerous solutions have been considered to control eutrophication and harmful algal blooms such as the biological removal of nitrogen and phosphorus. Advanced treatments (i.e. green technology) depend upon the remediation of wastewater before discharge, such as the removal of phosphorus using agricultural waste-based biosorbents (AWBs) from water and wastewater, and phosphorus sorption performance by both unmodified and modified AWBs. Phyto-remediation includes many procedures that encompass the cost-effective and environmentally friendly methods used to remove or reduce excess natural/inorganic contaminants in groundwater, surface water, and soil. Due to the rapid growth of duckweeds and their ability to rapidly remove minerals as phosphates and nitrogen from the water, duckweed may be the most promising plant for controlling eutrophication and, therefore, harmful algal blooms.