بررسي تاثير انتخابگرهاي سه مرحله اي اناكسيك بر كاهش پديده هاي حجيم شدن لجن

Impact of Three-Stage Anoxic Selector on Sludge Bulking Control.

Despite extensive research carried out on sludge bulking, it is still a common problem world-wide and a comprehensive solution is yet to be developed. In this research, the effect of three-stage anoxic selector on controlling activated sludge bulking is investigated in laboratory sludge systems. These experiments were carried out on two pilot plants; a three-stage anoxic selector preceding a complete mix system (experimental unit) and a complete mix system (control unit). Results from this study indicate that in selector zones with F/M ratios high enough to allow for rapid substrate uptake to occur predominately by floe forming microorganisms, the sludge settleability is influenced by the mode of substrate removal in the selector and by floe loading along the following lines. The substrate storage mechanism predominates in substrate removal for lower floe loadings, leading to improved sludge settleability, while for higher floe loadings the high rate metabolic mechanism predominates for substrate removal, leading to impoverished sludge settleability.