Effluent quality and reuse potential of wastewater treated in constructed wetlands in Southern Brazil

Abstract

The main objective of this study was to evaluate the quality and reuse potential of treated effluents by constructed wetlands (CW) systems utilized for decentralized wastewater treatment in urban and rural scenarios in southern Brazil. The assessment, based on Brazilian discharge standards and wastewater reuse guidelines, revealed a close link between treatment efficiency and technological configurations, considering diverse inlet wastewater sources. Most CW treated effluents complied with regulatory standards for disposal, prompting the exploration of reuse scenarios in urban and agricultural settings. However, the study underscores the imperative for rigorous disinfection due to the limited microbiological removal capacity of CW. Overall, the research emphasizes the adaptability and resilience of CW in treating diverse wastewater compositions, highlighting their pivotal role in advancing circular economy principles within sanitation services. Importantly, the findings suggest significant potential for treated wastewater reuse in both urban and agricultural settings. Urban applications, including toilet flushing, floor washing, and garden irrigation, prove feasible for CW systems situated in residential and commercial buildings. Meanwhile, rural CW systems demonstrate suitability for reclaimed water directed toward crop fertigation, tailored to the specific needs and irrigation methods of various crops. HIGHLIGHTS Nine systems with constructed wetlands adopted as secondary treatment units were analyzed.; The treated wastewater meets the quality required for its final disposal.; The treated wastewater has the potential to be reused in urban and agricultural scenarios.; Different design parameters were applied, reinforcing the robustness of the ecotechnology.; For effective reuse, it is necessary to conduct risk analysis studies.;

Keywords

• circular economy
• nature-based solutions
• treatment performance
• urban and agricultural settings