Nutrient removal in constructed wetlands: Especial emphasis on type of plantation method

Abstract

Constructed wetlands (CW) have emerged as sustainable and eco-friendly solutions for mitigating the impact of nutrient pollution in water bodies. Nutrient pollution, primarily caused by excess nitrogen and phosphorus, poses significant threats to aquatic ecosystems, leading to issues such as algal blooms, oxygen depletion, and impaired water quality. In response to these challenges, constructed wetlands have gained prominence as innovative systems capable of efficiently removing nutrients from wastewater and stormwater. These engineered ecosystems mimic the natural processes of wetlands to effectively treat wastewater. Among the key factors influencing the efficiency of nutrient removal, the choice of plantation method in CW stands out as a crucial aspect that demands closer scrutiny. As such, understanding the impact of different plantation methods on nutrient removal becomes paramount for optimizing the performance of constructed wetlands. This study focuses on elucidating the role of diverse vegetation strategies in enhancing the performance of these systems, with particular emphasis on nutrient uptake and transformation processes. Through a comprehensive review of existing literature, this research aims to identify and analyze the impact of various plantation techniques on nutrient removal efficiency. Factors such as plant species selection, plantation type i.e., single plant in a system (monoculture) or multiple vegetation in the system (polyculture) are examined to ascertain their influence on nitrogen and phosphorus removal rates. Polyculture improved TN and TP removal in horizontal subsurface CW by around 5%. However, a very high increment in treatment efficiency of both TN and TP was observed for vertical subsurface CW being more than 20%. Polyculture provided synergistic effect of various plant and microbial species for higher removal of nutrients from wastewater. Ultimately, the research aims to delineate the effect of plantation on performance of different CW in terms of mitigation of nutrient pollution in wastewater.