Impact of seasonal climate variability on constructed wetland treatment efficiency
Dykes, Charlotte, Pearson, Jonathan M., Bending, Gary D. and Abolfathi, Soroush
Free-water surface constructed wetlands (CWs) are sustainable, low emission, nature-based solutions for water and wastewater treatment. However, the discharge of nutrient-rich effluents from CWs treating wastewater can adversely impact freshwater ecosystems and exacerbate eutrophication. Despite their ecological benefits, limited research exists on the treatment efficiency and pollutant dynamics of CWs under varying seasonal and environmental pressures. This study investigates the treatment efficiency of an integrated CW (ICW) serving as a nature-based solution for treating partially treated wastewater before release into the environment. Our findings highlight the dynamic and sensitive mechanisms influencing nutrient removal in CWs, driven by seasonal hydraulic conditions, vegetation phenology, and climatic factors. The study provides critical insights for optimizing CW design and management under fluctuating environmental conditions to enhance their resilience, ensure regulatory compliance, and maintain long-term treatment efficiency. This understanding is essential for guiding future regulatory policies and ensuring that CWs meet water quality standards in response to climate pressures.