Constructed wetlands are man-made systems designed to enhance self-purification abilities of natural wetland ecosystems and improve water quality in both rural and urban areas. Constructed wetlands are a versatile technology that has been incorporated into water treatment schemes in both low- and high-income countries. Constructed wetlands were initially developed to meet basic treatment requirements focused on easily biodegradable organic pollution, suspended solids and nutrients. However, constructed wetland can be also used for the removal of other classes of pollutants, including those of emerging concern. Along with the increasing usage of antibiotics the spread of antimicrobial resistance (AMR) is a major global threat to public health, while wastewater is a main vector for AMR spread. Polishing constructed wetlands placed after conventional wastewater treatment facilities may serve as sink and buffer to AMR spread into the environment. However, currently little knowledge is available on the fate of AMR in those systems. In collaboration with Wessex Water, we are investigating the operation of newly constructed 2-ha constructed wetland system receiving wastewater from a rural catchment of a population equivalent of 2000 people. The project aims to understand the fate of pathogens and microbial ecology in constructed wetlands with emphasis on their role as a barrier for AMR dissemination. We use high-throughput 16S rRNA amplicon sequencing to identify functional bacterial communities and assess their role in wastewater treatment process in the given operational conditions. To detect and quantify presence of antimicrobial resistance and related pathogen indicators we use real-time PCR (qPCR). Microbial source tracking methods are applied to indicate cross-contamination events attributed to avian activity. The early results show, promising performance in terms of reducing nutrient load and abundance of AMR genes. This might indicate that the system which has not be primarily designed to deal with pathogen and AMR removal, possess certain treatment capacity that could be further enhanced through target-specific design.

About Franek Bydalek

Franciszek (Franek) Bydalek is a 3rd year PhD student at the Department of Chemical Engineering at the University of Bath. He is member of NERC Center for Doctoral Training in Freshwater and Bioscience and Sustainability at Cardiff University. Trained as an environmental engineer (West Pomeranian University of Technology, Poland) Franek has been fascinated by constructed wetlands early on in his career. Franek conducts interdisciplinary research linking engineering knowledge with passion for environmental science. Franek research activities also include sustainable water management practices such as phosphorus recovery, catchment scale management and decentralized wastewater treatment.