Long-term assessment on performance and seasonal optimal operation of a full-scale integrated multiple constructed wetland-pond system.

Constructed wetlands as natural process-based water treatment technologies are popular globally. However, lack of detailed long-term assessment on the impact of seasonal variations on their performance with focus on optimal seasonal adjustments of controllable operating parameters significantly limits their efficient and sustainable long-term operation. To address this, a full-scale integrated multiple surface flow constructed wetlands-pond system situated between slightly polluted river water and outflow-receiving waterworks in a subtropical monsoon climate area of middle-eastern China was seasonally assessed over a period of six years.