Impact of synthetic silver nanoparticles on microbial community structure and function of vertical and horizontal subsurface flow wastewater treatment system

The impact of synthetic silver nanoparticles on microbial community of mesocosm scale experimental wastewater treatment system was studied using Illumina based sequencing. Wastewater (mixture of domestic, municipal and industrial) from the inlet of the activated sludge wastewater treatment plant was pumped into the six parallel hybrid filter systems each consisting of a vertical subsurface flow filter (VF) followed by a horizontal subsurface flow filter (HF). During the 35-day long experiment, AgNP and AgNO3 solutions each were dosed into two corresponding VF mesocosms influents (0.1 mg Ag/L in influent), while two parallel subsystems were used as controls. Water samples from influent and effluent of VF were collected on day 35 and filter material samples from VF and HF mesocosms were collected on day 0 and 35. Microbial community profiling was performed using shotgun metagenomics (Illumina NextSeq 500 system).