Naturalization of treated wastewater by a constructed wetland in a water-scarce Mediterranean region

• DOI: 10.1016/j.jenvman.2024.120715
• Publication Date: 2024-04-04T22:29:46Z
• Authors: Carlos Rochera; María Peña; Antonio Picazo; Daniel Morant; Javier Miralles-L...; Alba Camacho-Sant...; María Belenguer-M...; Tatiana Montoya; Gloria Fayos; Antonio Camacho
• Keywords: Constructed wetland

The effluents from conventional wastewater treatment plants (WWTP), even if accomplishing quality regulations, substantially differ in their characteristics with those of waters natural environments. Constructed wetlands (CWs) serve as transitional ecosystems within WWTPs, mitigating these differences and restoring features before water is poured into the environment. Our study focused on an experimental surface-flow CW naturalizing WWTP effluent a semiarid area Eastern Spain. Despite relatively low pollutant concentrations entering CW, it effectively further reduced settled organic matter nitrogen. Dissolved (DOM) reaching was mainly protein-like, yet optical property changes DOM indicated increased humification, aromaticity, stabilization flowed through CW. Flow cytometry analysis revealed that released less abundant but more active bacterial populations than received. MiSeq Illumina sequencing highlighted prokaryotic community composition, phyla Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria dominating outflow. Functional prediction tools (FaproTax PICRUSt2) demonstrated shift towards microbial guilds aligned aquatic environments, aerobic chemoheterotrophs, photoautotrophs, metabolic reactions at higher redox potentials. Enhanced capabilities for degrading plant material correlated well pool. findings emphasize role CWs releasing biochemically stable functionally suited receiving Consequently, we propose naturalization nature-based solution (NBS) water-scarce regions like Mediterranean, where reclaimed discharged can significantly contribute to ecosystem's resources compared flows.