The aim of this study was to enhance the rhizobacterium potential in horizontal subsurface flow constructed wetland (CW) system planted by Phragmites australis using specific and lytic phages. The bioinoculation of specific bacteriophage for target bacteria; Salmonella typhi, and the monitoring of bacterial inactivation under different conditions showed the effectiveness of this methodology to enhance bacteria reduction and consequentially ameliorate purification performance of this studied biological treatment system. The injection of the phage at a concentration equal to 103 UFP/mL within the rhizosphere of the inoculated filter (F) was allowed 1 U-Log10 of improvement of bacterial inactivation compared to the control filter (T) nearly 1 logarithmic unit thus, a 90% improvement of bacteria reduction. When we increased the phage titer (105 UFP/mL), the bacterial reduction equal to 2.75 U-Log10 (N/N0) was registered that corresponds to a decrease of nearly 99.9%. According to the first-order model, the inactivation coefficient is equal to 2.29 min-1 (0.88 min-1 for the first experiment) and the bacterial reduction rate is 5 times higher than that determined for the control filter. This results show the positive impact of the phage in the bacterial inactivation and the improvement of water treatment of the biofilter C.
Keywords: Bioinoculation; constructed wetland; phage; rhizobacterium.