Genome-level insights into the operation of an on-site biological wastewater treatment unit reveal the importance of storage time

On-site wastewater treatment systems are gaining popularity in areas where centralized is not available. In the current case study a domestic activated sludge system was investigated, treated effluent stored short-term (1 week turn-over time) and long-term (over 2–3 months) storage tank then used for irrigation. This design provided unique opportunity to assess chemical microbial changes of upon storage. Long-term greatly improved both quality degradation efficiency most organic micropollutants examined, including petroleum hydrocarbons pesticide diethyltoluamide. Taxonomic profile core microbiome also influenced Relative abundance values members Azoarcus Thauera genera, which important degrading polycyclic aromatic compounds, clearly indicated biodegrading activity these microbes across samples. The xenobiotics functions correlated with observed micropollutant indicating efficient decomposition contaminants. Functions related infectious diseases had highest corresponding well relative indicator organisms implying significance time elimination pathogens. Based on results, small, on-site could benefit from effluent.