Wastewater to Wetlands: Turning the Tide with Azolla Ferns

Abstract

Water pollution is a major problem exacerbated by untreated wastewater discharged into the environment, leading to eutrophication and algal blooms. This research at the American University of Beirut explores the potential of using Azolla pinnata, an aquatic fern, to rid wastewater from ammonium (NH4-N) and soluble reactive phosphorus (SRP), which are the main contributors to eutrophication. A controlled phytoremediation experiment conducted at the Advancing Research and Enabling Communities (AREC) center in the Bekaa valley showed that A. pinnata can decrease NH4-N and SRP in the primary treated wastewater by 98.2% and 96.4% respectively, within 20 days. The color and odor of treated wastewater reverted to the characteristics of fresh water, making this recycling method highly sustainable due to its relatively low cost. The prospective project would be scaled to the university’s farm level by constructing artificial wetlands at AREC using wastewater generated by the farm facilities. The harvested Azolla can be used as animal feed and/or as a green fertilizer. Successfully reintroducing the precarious wetlands in that arid region would alleviate the stress on aquifers and replenish many endemic species currently on their way to extinction. As a result, the university would be treating its wastewater in a sustainable way while contributing to greening the landscape slowly transfigured by desertification.