Key Impacts of Iron Presence on Wastewater Treatment Through Subsurface Flow Constructed Wetlands: Critical Review

Abstract

Treatment effectiveness in subsurface vertical flow constructed wetlands is impacted by iron cations present in wastewater. Iron influences the makeup of microbial communities, pathways for the degradation of pollutants, and its interactions with organics and pollutants enhance the elimination of impurities by adsorption and precipitation. In artificial wetlands used for wastewater treatment, iron speciation is redox-dependent and involves changes to organic contaminants, phosphorus, nitrogen, and sulfur removal. But elevated iron levels can also result in the formation of iron oxides, which decrease water movement and substrate permeability. Effective design and operation of these wetlands depend on an understanding of the range of ideal iron concentrations for effective wastewater treatment.