Effects of Influent Algae Concentrations and Seasonal Variations on Pollutant Removal Performance in High-Rate Algae Ponds

Algae can increase pH and dissolved oxygen via photosynthesis and affect the wastewater treatment performance of high-rate algae ponds (HRAPs).Nine laboratory-scale HRAPs divided into three groups were constructed to treat synthetic wastewater via six-month experiments.Higher algae concentrations in the influent of HRAPs effectively promoted the wastewater treatment performance.Seasonal variation had a significant impact on algal growth.Summer tests exhibited a higher reduction of pollutants than autumn tests.The high-influent algae concentration group in summer (HRAP-A) largely reduced the TN by 52.7±3.0%,TP by 90.3±1.0%, and dissolved chemical oxygen demand (DCOD) by 99.0±1.0%.It outperformed the low influent algae concentration group in summer (HRAP-B) and was significantly higher than the high influent algae concentration group in autumn (HRAP-C).The appropriate operation and design of HRAPs contributed to efficient wastewater treatments.