Influence of irrigation with pulp and paper mill wastewater on bacterial communities of reed fields

The impact of wastewater on the ecological functioning of constructed wetland systems can be assessed by analyzing the microbial diversity, profiling, and community structure of soils irrigated with wastewater. In this study, we utilized in situ, culture-independent 16S rRNA sequencing technology to comprehensively investigate the biodiversity, abundance, and structure of bacterial communities in reed field soils irrigated with pretreated pulp and paper wastewater (PPW) and freshwater. Our results revealed significant differences in bacterial communities across freshwater-irrigated wetlands, short-term wastewater-irrigated wetlands, and long-term wastewater-irrigated wetlands. Redundancy analysis and Spearman's correlation analysis demonstrated that soil pollutants (TX and AOX), nutrients (TN and TP), and heavy metals significantly influenced the microbial community structure. These findings underscore the importance of microbial monitoring and suggest that irrigation should be discontinued after 10 years to facilitate the recovery of wetland ecosystems. • Wastewater irrigation time affects bacterial community structure and diversity. • Acidiferrobacter et al. key biomarkers indicate response to wastewater. • Soil pollutants, nutrients and heavy metals play key roles in microbial structure.