The Potential Application of Diatom-aided Constructed Floating Wetlands for Domestic Wastewater Treatment

Urbanization and industrialization have resulted in the generation of a large quantity of wastewater. The substantial amount of resources and capital requirement is driving the growing demand for sustainable, eco-friendly, and cost-effective treatment systems. In this context, extensive research is underway on Constructed Floating Wetlands (CFWs) for wastewater treatment. The present study attempts to treat real-domestic wastewater using diatoms and four different macrophytes, including Eichhornia crassipes, Salvinia molesta, Lemna minor, and Pistia stratiotes. Chemical oxygen demand (COD), phosphates, and total nitrogen (TN) were monitored to assess the ability of individual plants, diatoms, and their combinations to treat wastewater. COD, phosphate, and TN removal efficiencies varied from 56.4% to 86.5%, 64.8% to 99.1%, and 85% to 96.2% respectively, with the plants and their combination with diatoms. A 4-fold increase in wet biomass of the seeded plants and their roots was observed. This increased biomass and root length indicates the acclimatization of plants to the wastewater. The plant biomass produced during the treatment can be a potential substrate for bioenergy and bio-fertilizer production.