Energy Sources Part A-recovery Utilization and Environmental Effects, Vol.41, No.14, 1674-1682, 2019
Advanced wastewater treatment using filamentous algae in raceway ponds with underwater light
The current study evaluated nutrient removal efficiency, algae productivity, and economic feasibility related to cultivation of the filamentous algae, Hydrodictyon reticulatum, in a pilot plant-scale raceway pond with underwater light. Following the installation of an underwater light device, removal efficiencies of T-N and T-P increased by 11.0% and 12.3%, respectively. The productivity of algae also increased by 133.8% to 5.81 g/m(2)center dot d. Installation of the underwater light device increased the wastewater treatment capacity by over 3 times in the same area and enabled the removal of nutrients by over 3.5 times and removal of carbon dioxide by an additional 39 tons/yr. Estimates indicated that the cost of wastewater treatment and nutrient removal was reduced by more than 67%, while the production cost of H. reticulatum was reduced by 18% or more. Therefore, underwater light may solve issues related to the need for large sites in existing raceway ponds and enhance the economic efficiency by improving nutrient removal efficiency and productivity.