Comparative Study on the Denitrifying Phosphorus Removing Characteristics of MWTPs Guilin China

Denitrification activity of polyphosphate accumulating organisms (PAOs) in full-scale wastewater treatment plants

“…In all batch tests, the rate of anoxic P removal (rP) was on average a third of the rate of aerobic P removal (Table 1). This is similar to results obtained by Bai et al (2011), also with full-scale sludge. Once oxygen is introduced at the end of the anoxic phase, P uptake re-starts at a higher rate, but lower than the one observed when only an aerobic phase is supplied, as also observed by Kerrn-Jespersen and Henze (1993).…”

“…In terms of the ratios of P removed per electron acceptor (P/O2 for oxygen and P/N for nitrate) (Table 1), the values are similar to the ones reported by Bai et al (2011) for full-scale experiments but generally lower than previous values reported in literature for lab-scale enriched cultures both with nitrate and nitrite as electron acceptor (Table 1). This implies a lower overall efficiency of full-scale sludge to remove P in function of their electron acceptor.…”

“…Subsequent improvements were proposed, first by Meinhold et al (1999) and then by Oehmen et al (2010), to use the ratio of phosphate removal to avoid kinetic biases. Based on these methods, sporadic estimations of DPAOs vs. non-DPAOs have been carried out in lab-scale (Oehmen et al 2010;Wachtmeister et al 1997), pilot scale (Meinhold et al 1999;García-Usach et al 2010) and full-scale (Wachtmeister et al 1997;Bai et al 2011) studies. However, there has not been a systematic assessment of the efficiency of anoxic P removal vs. aerobic P removal in full-scale systems using nitrate, coupled with a microbiological analysis that could attempt to link DPAO fractions to the presence of Accumulibacter Type I and Type II or GAOs.…”