Effects of the chlorination and pressure flushing of drippers fed by reclaimed wastewater on biofouling

Milli-channel baffle labyrinths are widely used in drip irrigation systems. They induce a pressure drop enabling irrigation. However, with section thickness that is measured mm 2 , they sensitive to clogging, which reduces the performance and service life of system. The impact chlorination (1.5 ppm free chlorine during 1 h application) flushing (0.18 MPa) on biofouling non-pressure-compensating drippers, fed by real reclaimed wastewater, was studied at lab scale using optical coherence tomography. effect these treatments microbial composition (bacteria eukaryotes) also investigated High-throughput DNA sequencing. Biofouling mainly observed inlet, outlet return areas milli-labyrinth channel from drippers. Chlorination reduced biofilm development, particularly mainstream channel, it more efficient when combined flushing. Moreover, maintaining water distribution uniformity (CU < 95% compared less than 85% for unchlorinated lines). It efficiently bacterial concentration (?1 log) diversity community dripper biofilms method. significantly modified communities, promoting chlorine-resistant bacteria such as Comamonadaceae or Azospira . Inversely, several groups were identified Chloroflexi Planctomycetes. Nevertheless, one month after stopping recovered chlorine-sensitive phylum Saprospiraceae Spirochaetaceae Christensenellaceae Hydrogenophilaceae families re-emerged conjunction growth biofouling, highlighting resilience originating Based PCoA analyses, structure communities still clustered separately non-chlorinated showing detectable treatment. • lateral commonly prevent biofouling. Biofilm lowest ?-Proteobacteria Firmicutes contain resistant bacteria. decrease (filamentous bacteria) transitory. resilient interruption cleaning events.